A method for evaluating the protection of a fire breathing protection article

Abstract

The protection evaluation method of the fire respiratory protection articles of the present invention realizes the high-throughput, high-sensitivity, and high-resolution on-line detection of trace complex components by on-line analyzing trace complex component toxic and harmful gases and human exhaled air. The established effectiveness evaluation technology of respiratory protection articles based on high-throughput mass spectrometry detection of trace complex components has the advantages of fast speed, high sensitivity, simplicity, and friendliness. The evaluation of the filtration effect of respiratory protection articles on trace toxic and harmful gases provides respiratory safety guarantee for fire investigators, and has significant economic and social benefits for scientific and effective protection and reduction of occupational hazards; the indicators are specific, applicable to the evaluation of various protection articles, and have good applicability.

Description

Technical Field

[0001] The present invention relates to the technical field of protective article evaluation, and particularly to a method for evaluating the protection of fire breathing protective articles. Background Art

[0002] Smoke in a fire has become the number one killer. According to incomplete statistics, the number of people killed by smoke in fires accounts for more than 80% of the total number of fire deaths each year. Fire smoke is the product generated by the thermal decomposition or combustion of combustible materials during the occurrence and development of a fire, or other gases volatilized by heat. Its components mainly include carbon-containing particles with a particle size of a few micrometers to dozens of micrometers and a variety of small molecule gases. Especially with the rapid development of China's economy, many high molecular chemical materials have been widely used. In particular, a large amount of synthetic fibers, plastics, synthetic rubbers and other high molecular compounds are used in interior building decoration. These materials will generate a large amount of smoke during combustion and thermal decomposition, and their components may contain formaldehyde, saturated hydrocarbons, acetone, benzene, toluene, and some chlorinated hydrocarbons (vinyl chloride, chloroform, carbon tetrachloride), acrolein, etc., making the components of toxic and harmful substances in the smoke more complex;

[0003] At present, domestic and foreign research departments only study toxic gases in the fire field in several stages such as the occurrence, development, and fire fighting and rescue of a fire, but there is no research on the residual toxic and harmful gases in the post-fire investigation stage; with the progress of society, fire investigators pay more and more attention to occupational health and safety issues, and objectively require research on occupational hazard factors and corresponding protective products. In particular, the effective protection against occupational hazard factors such as chemical toxic and harmful substances is one of the hotspots of attention.

[0004] The prior art has not disclosed an evaluation method for fire breathing protective articles.

[0005] Therefore, the technical personnel in this field are committed to developing an evaluation method for the protection of fire breathing protective articles to solve the above deficiencies of the prior art. Summary of the Invention

[0006] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is the defect that there is no publicly disclosed evaluation method for fire breathing protective articles in the current prior art.

[0007] To achieve the above object, the present invention provides a method for evaluating the protection of fire breathing protective articles, including the following steps:

[0008] Step 1: Determine the gas components in the fire environment; determine the evaluation index of the fire breathing protective article according to the gas components in the fire environment;

[0009] Step 2: Set up a respiratory protection equipment testing device to simulate the breathing process of a normal person wearing respiratory protection equipment. Prepare VOCs standard gas according to the gas components obtained in Step 1, simulate the fire scene environment, and conduct respiratory protection tests on each respiratory protection equipment to be evaluated; Monitor in real time and online the concentration change information of toxic and harmful gases in the simulated environment after passing through the respiratory protection equipment, and record the protection effect data of the respiratory protection equipment.

[0010] The respiratory protection test includes the following steps: Step 2-1: Fill a clean Tedlar gas bag with nitrogen, then use a syringe to draw a mixed gas from the Tedlar gas bag containing the mother gas and inject it into the Tedlar gas bag. Shake the gas bag and then let it stand for about 20 minutes to make the gas in the gas bag mix evenly, and finally obtain a mixed gas of benzene, 1-hexene, toluene, styrene, xylene, chlorobenzene, n-hexane, and tetrachloroethylene.

[0011] Step 2-2: Open the HPPI-TOFMS control software, load the test parameters, and wait for the instrument signal to stabilize; Connect the flow controller and the air pump with a capillary and a quick connector, open the air pump, and set the flow rate of the flow controller.

[0012] Step 2-3: Connect the Tedlar gas bag directly to the HPPI-TOFMS injection capillary with a quick connector to detect the signal intensity of the mixed gas without passing through the mask.

[0013] Step 2-4: Fix the respiratory protection equipment to be evaluated with a sealing and fixing device, connect the sealing and fixing device to the gas bag and the HPPI-TOFMS injection capillary with quick connectors, and detect the signal intensity of the mixed gas after passing through the respiratory protection equipment to be evaluated; Adopt the continuous monitoring mode, accumulate the signal intensity at each point for 30 seconds, stop the detection when the signal intensity of each respiratory protection equipment to be evaluated is stable, parallelly detect two of each type of respiratory protection equipment to be evaluated, and take the average value of the data of the two respiratory protection equipment to be evaluated when processing the data.

[0014] At the same time, introduce nitric oxide molecules to promote the ionization of formaldehyde molecules. The ionization mechanism formula is:

[0015] NO + h γ = NO + + e -

[0016] CH2O + NO+ = [CH2O]NO +

[0017] Step 3: Evaluate and analyze the existing respiratory protection equipment based on the data obtained from the test in Step 2, and draw a conclusion on the evaluation of the respiratory protection equipment for this fire.

[0018] Further, in the step 1, the determination of the fire environmental gas components includes collecting the environmental gas at the fire scene, analyzing the fire scene gas sample by HPPI-TOFMS to obtain the types of residual VOCs gas in the air at each fire scene;

[0019] Further, in the step 2, the respiratory protection equipment testing device includes a Tedlar gas bag, a sealing and fixing device, a mass spectrometer, a flow meter, and a suction pump; the Tedlar gas bag, the sealing and fixing device, the mass spectrometer, the flow meter, and the suction pump are connected in sequence; the suction pump is used to simulate the actual breathing flow of the human body; the sealing and fixing device includes two stainless steel cup-shaped clamps with their openings buckled together, clamping the respiratory protection equipment to be evaluated in the middle, and a rubber O-ring is arranged at the opening sealing surface of the cup-shaped clamp to achieve sealing, avoiding the leakage of toxic and harmful sample gases and the influence of the penetration of external environmental air on the experiment; pipeline interfaces are arranged at the bottoms of the two cup-shaped clamps, one end is connected to the air outlet of the Tedlar gas bag, and the other end is connected to the sampling capillary of the mass spectrometer and the suction pump through a tee;

[0020] Further, in the step 2, the preparation of the VOCs standard gas includes the preparation of formaldehyde standard gas and the preparation of a mixed standard gas of 8 VOCs other than formaldehyde;

[0021] Further, in the step 3, the evaluation and analysis criteria are as follows: among the concentration decrease amplitudes of the 9 VOCs of each respiratory protection equipment to be evaluated after passing through the respiratory protection equipment to be evaluated,

[0022] if the concentration decrease amplitude of each of the 9 data is below 35%, it is an extremely poor respiratory protection equipment;

[0023] if the concentration decrease amplitude of each of the 9 data is between 35% and 55%, it is a poor respiratory protection equipment;

[0024] if the concentration decrease amplitude of each of the 9 data is between 55% and 75%, it is a medium respiratory protection equipment;

[0025] if the concentration decrease amplitude of each of the 9 data is between 75% and 90%, it is an excellent respiratory protection equipment;

[0026] if the concentration decrease amplitude of each of the 9 data is between 90% and 100%, it is an extremely excellent respiratory protection equipment;

[0027] if only 1 - 2 of the 9 data have a concentration decrease amplitude higher than 35% and the concentration decrease amplitudes of the other data are lower than 35%, it is a poor respiratory protection equipment;

[0028] if 3 - 6 of the 9 data have a concentration decrease amplitude higher than 35% and the concentration decrease amplitudes of the other data are lower than 35%, it is a medium respiratory protection equipment;

[0029] Among the 9 data, if the concentration decline of 6 - 9 data is higher than 35%, and the concentration decline of other data is lower than 35%, it is an excellent respiratory protection product;

[0030] Among the 9 data, if only 1 - 2 data have a significantly higher concentration decline than other data, and the concentration decline of other data is lower than 35%, it is a special respiratory protection product for the toxic and harmful gas;

[0031] Furthermore, for the protection evaluation method of the fire respiratory protection product, in step 2, the respiratory protection product testing device for testing can also be actual fire investigators. The specific operation is to detect the components of the exhaled gas of the fire investigators before entering the fire scene and after leaving the fire scene respectively, and conduct comparative analysis to obtain the types of residual VOCs gas in the exhaled gas of the fire investigators, and evaluate the protection effect of the protection products used by the fire investigators in this investigation;

[0032] Furthermore, for the protection evaluation method of the fire respiratory protection product, the types of residual VOCs gas in the exhaled gas of the fire investigators can also be collected and transmitted into the big database. Through qualitative and quantitative analysis of the chemical components in the exhaled gas of the investigators, reliable evaluation of the health risks of fire investigators can be achieved;

[0033] In the specific implementation manner of the present invention, in step 1, the types of VOCs in the fire scene gas can be roughly divided into 8 categories, namely ketones, olefins, alkanes, alcohols, aromatic hydrocarbons, esters, halogenated hydrocarbons, and others; the determined evaluation indicators include formaldehyde, benzene, hexene, toluene, styrene, xylene, chlorobenzene, hexane, and tetrachloroethylene;

[0034] In the specific implementation manner of the present invention, in step 2, the respiratory protection product to be evaluated is a mask;

[0035] Adopting the above - mentioned scheme, the protection evaluation method of the fire respiratory protection product disclosed by the present invention has the following advantages:

[0036] (1) The protection evaluation method of the fire respiratory protection product of the present invention realizes high - throughput, high - sensitivity, and high - resolution online detection of trace complex components through online analysis of trace complex component toxic and harmful gases and human exhaled gas. The established effectiveness evaluation technology of respiratory protection products based on high - throughput mass spectrometry detection of trace complex components has the advantages of fast speed, high sensitivity, simplicity, and friendliness. The evaluation of the filtration effect of respiratory protection products on trace toxic and harmful gases provides respiratory safety protection for fire investigators, and has significant economic and social benefits for scientific, effective protection and reduction of occupational hazards;

[0037] (2) The protection evaluation method of the fire breathing protection articles of the present invention has specific indicators, is applicable to the evaluation of various protection articles, and has good applicability;

[0038] In summary, the protection evaluation method of the fire breathing protection articles disclosed by the present invention realizes the high-throughput, high-sensitivity, and high-resolution on-line detection of trace complex components by on-line analyzing trace complex component toxic and harmful gases and human exhaled breath. The established effectiveness evaluation technology of breathing protection articles based on high-throughput mass spectrometry detection of trace complex components has the advantages of fast speed, high sensitivity, simplicity, and friendliness. The evaluation of the filtering effect of breathing protection articles on trace toxic and harmful gases provides breathing safety guarantee for fire investigators, and has significant economic and social benefits for scientific and effective protection and reduction of occupational hazards; the indicators are specific, applicable to the evaluation of various protection articles, and have good applicability.

[0039] The following will further illustrate the concept, specific technical solutions and technical effects of the present invention in combination with specific embodiments to fully understand the purpose, features and effects of the present invention. Brief Description of the Drawings

[0040] Figure 1 It is a schematic diagram of the principle structure of HPPI-TOFMS in Embodiment 1 of the present invention;

[0041] Figure 2 It is a statistical chart of the mass spectrometry resolution calculated by Gaussian fitting of the mass spectrometry peak at m / z = 92 in Embodiment 1 of the present invention;

[0042] Figure 3 It is a mass spectrometry diagram of the gas sample at the fire scene of a residential building in Embodiment 1 of the present invention;

[0043] Figure 4 It is a mass spectrometry diagram of the gas sample at the fire scene of a certain restaurant in Embodiment 1 of the present invention;

[0044] Figure 5 It is a mass spectrometry diagram of the gas sample at the fire scene of a certain "three-in-one" place in Embodiment 1 of the present invention;

[0045] Figure 6 It is a flow chart of the mask protection test experiment in Embodiment 1 of the present invention; from left to right in the direction of gas flow are Tedlar gas bag, mask sealing and fixing device, mass spectrometer, flow meter, and air pump;

[0046] Figure 7 It is a physical diagram of the mask sealing and fixing device in Embodiment 1 of the present invention;

[0047] Figure 8Statistical chart of the concentration changes of formaldehyde, benzene, toluene, xylene, styrene, chlorobenzene and hexene before and after the sample gas of Example 1 of the present invention passes through the DOCTOR MASK activated carbon mask;

[0048] Figure 9 Statistical chart of the concentration of hexane and tetrachloroethylene before and after the sample gas of Example 1 of the present invention passes through the DOCTOR MASK activated carbon mask;

[0049] Figure 10 Statistical chart of the concentration changes of formaldehyde, benzene, toluene, xylene, styrene, chlorobenzene and hexene before and after the sample gas of Example 1 of the present invention passes through a disposable mask;

[0050] Figure 11 Statistical chart of the concentration changes of hexane and tetrachloroethylene before and after the sample gas of Example 1 of the present invention passes through a disposable mask;

[0051] Figure 12 Statistical chart of the concentration changes of formaldehyde, benzene, toluene, xylene, styrene, chlorobenzene and hexene before and after the sample gas of Example 1 of the present invention passes through the Reboo mask;

[0052] Figure 13 Statistical chart of the concentration changes of hexane and tetrachloroethylene before and after the sample gas of Example 1 of the present invention passes through the Reboo mask;

[0053] Figure 14 Statistical chart of the concentration changes of formaldehyde, benzene, toluene, xylene, styrene, chlorobenzene and hexene before and after the sample gas of Example 1 of the present invention passes through the Songyan KN95 mask (with a breathing valve);

[0054] Figure 15 Statistical chart of the concentration changes of hexane and tetrachloroethylene before and after the sample gas of Example 1 of the present invention passes through the Songyan KN95 mask (with a breathing valve);

[0055] Figure 16 Statistical chart of the concentration changes of benzene, toluene, xylene, styrene, chlorobenzene and hexene before and after the sample gas of Example 1 of the present invention passes through the KN95 protective mask;

[0056] Figure 17 Statistical chart of the concentration changes of hexane and tetrachloroethylene before and after the sample gas of Example 1 of the present invention passes through the KN95 protective mask;

[0057] Figure 18 Statistical chart of the concentration changes of benzene, toluene, xylene, styrene, chlorobenzene and hexene before and after the sample gas of Example 1 of the present invention passes through the 3M 3200CN gas mask half-mask;

[0058] Figure 19It is the enrichment statistical chart of hexane and tetrachloroethylene before and after the sample gas of Embodiment 1 of the present invention passes through the 3M 3200CN gas mask half-mask;

[0059] Figure 20 It is the comparative mass spectrometry chart of the exhaled breath of Fire Investigation Personnel Chen of Embodiment 1 of the present invention before and after entering and leaving the fire scene;

[0060] Figure 21 It is the comparative mass spectrometry chart of the exhaled breath of Fire Investigation Personnel Sun of Embodiment 1 of the present invention before and after entering and leaving the fire scene;

[0061] Figure 22 It is the comparative mass spectrometry chart of the exhaled breath of Fire Investigation Personnel Zhang of Embodiment 1 of the present invention before and after entering and leaving the fire scene;

[0062] Figure 23 It is the comparative mass spectrometry chart of the exhaled breath of Fire Investigation Personnel Bao of Embodiment 1 of the present invention before and after entering and leaving the fire scene;

[0063] Figure 24 It is the physical picture of the DOCTOR MASK activated carbon mask;

[0064] Figure 25 It is the physical picture of the disposable mask;

[0065] Figure 26 It is the physical picture of the Reboo mask;

[0066] Figure 27 It is the physical picture of the Songyan KN95 mask (with a breathing valve);

[0067] Figure 28 It is the physical picture of the KN95 protective mask;

[0068] Figure 29 It is the physical picture of the 3M 3200CN gas mask half-mask; Detailed implementation manners

[0069] The following introduces multiple preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and these embodiments are exemplary descriptions. The protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0070] In the detailed implementation manners of the present invention, a method for evaluating the protection of a fire breathing protection article of the present invention includes the following steps:

[0071] Step 1: Collect the environmental gas at the fire scene, conduct HPPI-TOFMS analysis on the fire scene gas sample, and obtain the types of residual VOCs gas in the air at each fire scene; the types of VOCs in the fire scene gas can be roughly divided into 8 categories, namely ketones, olefins, alkanes, alcohols, aromatic hydrocarbons, esters, halogenated hydrocarbons, and others; the determined evaluation indicators include formaldehyde, benzene, hexene, toluene, styrene, xylene, chlorobenzene, hexane, and tetrachloroethylene.

[0072] Step 2: Build a respiratory protection equipment test device, which includes a Tedlar gas bag, a sealing and fixing device, a mass spectrometer, a flow meter, and a suction pump; the Tedlar gas bag, the sealing and fixing device, the mass spectrometer, the flow meter, and the suction pump are connected in sequence; the suction pump is used to simulate the actual breathing flow of the human body; the sealing and fixing device includes two stainless steel cup-shaped jigs with their openings buckled together, clamping the mask in the middle, and a rubber O-ring is set at the opening sealing surface of the cup-shaped jig to achieve sealing, avoiding the leakage of toxic and harmful sample gas and the influence of the penetration of external environmental air on the experiment; pipeline interfaces are provided at the bottoms of the two cup-shaped jigs, one end is connected to the air outlet of the Tedlar gas bag, and the other end is connected to the sampling capillary of the mass spectrometer and the suction pump through a three-way joint.

[0073] Prepare VOCs standard gas according to the gas components obtained in Step 1, including the preparation of formaldehyde standard gas and the preparation of a mixed standard gas of 8 VOCs other than formaldehyde, simulate the fire scene environment, and conduct respiratory protection tests on each mask; real-time online monitor the concentration change information of toxic and harmful gases in the simulated environment after passing through the respiratory protection equipment, and record the protection effect data of the respiratory protection equipment; the respiratory protection test includes Step 2-1: Fill nitrogen into a clean Tedlar gas bag, then use a syringe to extract the mixed gas from the Tedlar gas bag containing the mother gas and inject it into the Tedlar gas bag, shake the gas bag and then let it stand for about 20 minutes to make the gas in the gas bag mix evenly, and finally obtain a mixed gas of benzene, 1-hexene, toluene, styrene, xylene, chlorobenzene, n-hexane, and tetrachloroethylene.

[0074] Step 2-2: Open the HPPI-TOFMS control software, load the test parameters, and wait for the instrument signal to be stable; connect the flow controller and the suction pump with a capillary and a quick connector, turn on the suction pump, and set the flow rate of the flow controller.

[0075] Step 2-3: Connect the Tedlar gas bag directly to the HPPI-TOFMS sampling capillary with a quick connector to detect the signal intensity of the mixed gas without passing through the mask.

[0076] Step 2-4: Fix the mask with the sealing and fixing device, connect the sealing and fixing device to the air bag and the HPPI-TOFMS sampling capillary with a quick connector, and detect the signal intensity of the mixed gas after passing through the mask; adopt the continuous monitoring mode, accumulate the signal intensity at each point for 30 s, stop the detection when the signal intensity of each mask is stable, detect two masks in parallel for each type of mask, and take the average value of the data of the two masks when processing the data.

[0077] Meanwhile, introduce nitric oxide molecules to promote the ionization of formaldehyde molecules. The ionization mechanism formula is:

[0078] NO + h γ = NO + + e -

[0079] CH2O + NO+ = [CH2O]NO +

[0080] Step 3: Based on the data obtained from the test in Step 2, evaluate and analyze the existing respiratory protection products, and draw the evaluation conclusion of the respiratory protection products in this fire.

[0081] The evaluation and analysis criteria are as follows: for the 9 VOCs of each mask, among the concentration decrease ranges after passing through the mask,

[0082] if the concentration decrease range of each of the 9 data is below 35%, it is a very poor respiratory protection product;

[0083] if the concentration decrease range of each of the 9 data is 35% - 55%, it is a poor respiratory protection product;

[0084] if the concentration decrease range of each of the 9 data is 55% - 75%, it is a medium respiratory protection product;

[0085] if the concentration decrease range of each of the 9 data is 75% - 90%, it is an excellent respiratory protection product;

[0086] if the concentration decrease range of each of the 9 data is 90% - 100%, it is an extremely excellent respiratory protection product;

[0087] if only 1 - 2 of the 9 data have a concentration decrease range higher than 35% and the concentration decrease ranges of the other data are below 35%, it is a poor respiratory protection product;

[0088] if 3 - 6 of the 9 data have a concentration decrease range higher than 35% and the concentration decrease ranges of the other data are below 35%, it is a medium respiratory protection product;

[0089] Among the 9 data, if 6 - 9 data have a concentration decrease rate higher than 35%, and the concentration decrease rates of the other data are all lower than 35%, it is an excellent respiratory protection product;

[0090] Among the 9 data, if only 1 - 2 data have a significantly higher concentration decrease rate than the other data, and the concentration decrease rates of the other data are all lower than 35%, it is a special respiratory protection product for the toxic and harmful gas;

[0091] Example 1

[0092] Experimental device: The instrument used is a high - pressure photoionization - time - of - flight mass spectrometer HPPI - TOFMS R5020 based on vacuum ultraviolet lamp (VUV), as Figure 1 、 Figure 2 shown in Table 1;

[0093] Device experimental principle: Adopt VUV photoionization technology under high pressure, combined with a vertical acceleration reflection - type time - of - flight mass analyzer for experiments;

[0094] Table 1 Instrument performance indicators

[0095] Parameter Name Technical Index Sensitivity 50ppt (Direct measurement of toluene, accumulation for 30 s) Mass Resolution 5000 (At mass-to-charge ratio m / z 92) Mass Range 1 - 1000 amu Linear Range > 3 orders of magnitude Single Sample Analysis Time 30s

[0096] Step 1: Determine the gas components in the fire environment; determine the evaluation indicators for fire respiratory protection products according to the gas components in the fire environment;

[0097] Step 1 - 1: Collect the gas in the fire scene environment

[0098] Use Tedlar sampling bags and sampling pumps to collect environmental gas as analysis samples during the on - site investigation of building fires in Fushun and Liaoyang. The samples are randomly collected by fire investigators. 2 gas samples are collected at each fire scene, 1 as an analysis sample and 1 as a duplicate sample, for a total of 32 fire scene samples.

[0099] Step 1 - 2: Test the residual VOCs gas in the fire scene ambient air

[0100] Before mass spectrometry detection, first place the gas bag containing the sample gas in a vacuum drying oven and keep it at a constant temperature of 40°C for 1 h to desorb the VOCs components adsorbed on the inner wall of the gas bag, preventing some VOCs components from being adsorbed on the inner wall of the gas bag during gas bag sampling and storage, resulting in loss of sample components and measurement errors.

[0101] Take out the gas bag, connect the gas bag to the HPPI - TOFMS injection port with a quick connector, and directly inject for analysis, ensuring that the entire detection is completed within 10 min under room temperature conditions (20 ± 2°C).

[0102] Detection conditions: The pressure in the ionization region is 450 Pa, the sampling and accumulation time for each spectrum is 30 s, each gas bag is detected in parallel three times, and the average value is finally taken.

[0103] Steps 1-3: HPPI-TOFMS analysis was performed on 32 fire scene gas samples collected, and the types of VOCs remaining in the air at each fire scene were obtained. For example,

[0104] Figure 3 is the mass spectrometry analysis chart of the gas sample collected at a residential house fire scene. It can be seen from the chart that 39 gases with relatively high concentrations were qualitatively analyzed, and they can be roughly divided into 8 categories; namely ketones (acetone, methyl vinyl ketone, butanone, cyclohexanone, etc.), aldehydes (propanal), alkenes (butadiene, butene, hexadiene, hexene, heptene, octene, nonene, limonene, etc.), alkanes (cyclohexane, hexane, cyclopentane, octane, nonane, etc.), alcohols (ethanol, ethylene glycol, ethanethiol, propylene glycol, etc.), aromatic hydrocarbons (benzene, toluene, xylene, trimethylbenzene, butylbenzene, etc.), esters (ethyl formate, ethyl acetate), halogenated hydrocarbons (chlorobenzene) and others (acetic acid, propionitrile, furan, pyridine, etc.).

[0105] Figure 4 is the mass spectrometry analysis chart of the gas sample collected at a restaurant fire scene. It can be seen from the chart that 37 gases with relatively high concentrations were qualitatively analyzed, and they can also be roughly divided into 8 categories; namely ketones (acetone, butanone), aldehydes (acetaldehyde, propanal), alkenes (butadiene, butene, pentene, styrene, cyclohexene, heptene, octene, nonene, limonene, etc.), alkanes (pentane, heptane, octane, nonane, etc.), alcohols (ethanol, ethylene glycol, ethanethiol), aromatic hydrocarbons (benzene, toluene, xylene, trimethylbenzene, butylbenzene), esters (ethyl acetate), halogenated hydrocarbons (chlorobenzene) and others (acetonitrile, propionitrile, acetic acid, pyridine, thiophene, benzoic acid, aniline).

[0106] Figure 5 is the mass spectrometry analysis chart of the gas sample collected at a three-in-one place fire scene. It can be seen from the chart that 44 gases with relatively high concentrations were qualitatively analyzed, and they can also be roughly divided into 8 categories; namely ketones (acetone, butanone), aldehydes (propanal), alkenes (butadiene, butene, cyclopentadiene, isoprene, pentene, cyclohexene, heptene, styrene, heptadiene, octene, nonene, limonene, etc.), alkanes (pentane, hexane, heptane, octane, nonane), alcohols (ethanol, ethylene glycol, ethanethiol, propylene glycol), aromatic hydrocarbons (benzene, toluene, xylene, trimethylbenzene, butylbenzene), esters (ethyl formate, ethyl acetate), halogenated hydrocarbons (chlorobenzene) and others (acetonitrile, propionitrile, acetic acid, furan, thiophene, pyridine, valeric acid, benzoic acid, aniline, dimethylaniline).

[0107] In the above three gas samples, a total of 58 volatile organic compounds were detected, and the information of each compound is summarized in Table 2.

[0108] Summary Table of Gas Components at Fire Scene in Table 2

[0109]

[0110]

[0111]

[0112] Step 1-4: Draw conclusions from the analysis results of 32 fire scene samples;

[0113] The types of VOCs in fire scene gases can be roughly divided into 8 categories, namely ketones, olefins, alkanes, alcohols, aromatic hydrocarbons, esters, halogenated hydrocarbons and others. However, the gas categories and contents in each type of gas are different.

[0114] Step 1-5: Determine the evaluation indicators for fire breathing protection equipment;

[0115] According to what is obtained in Step 1-4, the evaluation indicators for fire breathing protection equipment include formaldehyde, benzene, hexene, toluene, styrene, xylene, chlorobenzene, hexane, and tetrachloroethylene;

[0116] Step 2: Select various types of masks as protective equipment, build a breathing protection equipment test device, simulate the breathing process of a normal person wearing breathing protection equipment, prepare VOCs standard gas according to the gas components obtained in Step 1, and simulate the fire scene environment; use high-pressure photoionization-time-of-flight mass spectrometry to systematically test the filtration effects of 6 common masks on the market for typical VOCs in the fire scene.

[0117] Step 2-1: Determine the types of masks for the test

[0118] A total of six common protective masks on the market are selected. The specific information of each protective equipment is shown in Table 3.

[0119] Summary Table of Protective Mask Information in Table 3

[0120]

[0121]

[0122] Step 2-2: Build a mask test device

[0123] The test device includes a Tedlar gas bag, a mask sealing and fixing device, a mass spectrometer, a flow meter, and a suction pump; the Tedlar gas bag, the mask sealing and fixing device, the mass spectrometer, the flow meter, and the suction pump are connected in sequence; the suction pump is used to more realistically simulate the actual breathing flow rate of the human body (between 15 - 80 L / min); the mask test experimental device is as Figure 6 shown;

[0124] The mask sealing and fixing device is as follows Figure 7 shown, including two stainless steel cup-shaped clamps that are buckled with their openings facing each other, clamping the mask in the middle. A rubber O-ring is provided at the opening sealing surface of the cup-shaped clamp to achieve sealing, avoiding the leakage of toxic and harmful sample gases and the influence of external environmental air penetration on the experiment; Pipeline interfaces are provided at the bottoms of the two cup-shaped clamps. One end is connected to the air outlet of the Tedlar gas bag, and the other end is connected to the inlet capillary of the mass spectrometer and the air extraction pump through a three-way joint.

[0125] The effective breathable surface of the mask is a circle with a diameter of φ56mm, and the breathable area is about 25cm2. Since the area of commercially available masks is usually about 200cm2, and although the gas flow rate during normal human breathing varies at different positions of the mask, there is gas flow across the entire mask surface. Therefore, considering the actual situation, in this embodiment, the pumping speed is fixed at 10L / min, and the breathable flow rate converted to the entire mask surface can reach a maximum of 80L / min, meeting the actual breathing volume of 15 - 80L / min under different working or exercise intensities of the human body.

[0126] Step 2 - 3, Preparation of VOCs standard gas

[0127] According to the VOCs components in the ambient air at the fire scene tested above, it mainly includes benzene series, aldehydes, straight-chain alkenes, alkanes, and some halogenated alkenes and other substances. Therefore, when evaluating the VOCs protection effects of different masks, according to the content of VOCs in the air at the fire scene in Step 1 and the literature reports, 1 - 2 types of each kind of VOCs are selected to simulate the ambient air at the fire scene, and standard gases are configured. The compound information is summarized in Table 4.

[0128] Preparation of formaldehyde standard gas: Fill 200L of nitrogen into a clean 300L Tedlar gas bag, then inject the sample from the formaldehyde injection port, and detect the background of the gas bag with HPPI - TOFMS; Then fill 40L of 3ppmV formaldehyde into the Tedlar gas bag, and finally obtain 500ppbV of formaldehyde gas.

[0129] Preparation of 8-VOCs mixed standard gas except formaldehyde: After purging a 3-L Tedlar gas bag with clean air, the nitrogen flow rate was controlled by a flow controller, and 2 L of high-purity nitrogen was injected into the Tedlar gas bag. Then, 7.25 μL of benzene, 10.20 μL of 1-hexene, 419.66 μL of n-hexane, 8.86 μL of toluene, 9.44 μL of styrene, 10.07 μL of xylene, 8.3 μL of chlorobenzene, and 41.73 μL of tetrachloroethylene were successively injected into the gas bag with a microsyringe. Then, the gas bag was purged with a hot air gun to accelerate the volatilization of the organic substances and make them mix evenly. Finally, a mixed mother gas of 8 VOCs was obtained, in which the concentrations of benzene, 1-hexene, toluene, styrene, xylene, and chlorobenzene were 1000 ppmV, the concentration of n-hexane was 40000 ppmV, and the concentration of tetrachloroethylene was 5000 ppmV.

[0130] Table 4 Summary of information on 9 typical VOCs selected

[0131]

[0132] Step 2-4: Test the protective effect of the mask

[0133] Step 2-4-1: Charge 260 L of nitrogen into a clean 300-L Tedlar gas bag, and then use a syringe to extract 260 mL of the mixed gas from the 3-L Tedlar gas bag containing the mother gas and inject it into the 300-L Tedlar gas bag. Shake the 300-L gas bag and then let it stand for about 20 min to make the gas in the bag mix evenly. Finally, a mixed gas with concentrations of benzene, 1-hexene, toluene, styrene, xylene, and chlorobenzene of 1 ppmV, the concentration of n-hexane of 40 ppmV, and the concentration of tetrachloroethylene of 5 ppmV was obtained.

[0134] Step 2-4-2: Open the HPPI-TOFMS control software, load the test parameters, and wait for the instrument signal to stabilize. Connect the flow controller (30 L / min) and the air pump with a Φ4 capillary and a quick connector. Open the air pump and set the flow rate of the flow controller at 10 L / min.

[0135] Step 2-4-3: First, connect the Tedlar gas bag directly to the HPPI-TOFMS injection capillary with a quick connector to detect the signal intensity of the mixed gas without passing through the mask for about 2 min.

[0136] Step 2-4-4: Fix the mask with a mask fixing device, connect the mask fixing device to the gas bag and the HPPI-TOFMS injection capillary with quick connectors, and detect the signal intensity of the mixed gas after passing through the mask. In the continuous monitoring mode, the signal intensity at each point is accumulated for 30 s. The detection stops when the signal intensity of each mask is stable. Two masks of each type are detected in parallel, and the average value of the data of the two masks is taken when processing the data.

[0137] Since the ionization energy of formaldehyde (10.88 eV) is higher than the energy of photons generated by the VUV lamp (10.64 eV), direct photoionization cannot effectively ionize formaldehyde molecules. Therefore, nitrogen monoxide molecules are introduced to promote the ionization of formaldehyde molecules, and the ionization mechanism is as follows:

[0138] NO + h γ =NO + + e -

[0139] CH2O + NO+ = [CH2O]NO +

[0140] Step 2-5, Data analysis

[0141] Step 2-5-1, Data of DOCTOR MASK activated carbon mask

[0142] The DOCTOR MASK activated carbon mask adopts a four-layer design. The moisture-proof layer (outer layer) prevents fog and water vapor from penetrating; the activated carbon layer (the middle layer) adsorbs organic gases harmful to the human body and removes odors; the filter mesh layer (the middle second layer) blocks fine dust and bacteria from invading the human body; the ultra-soft fiber layer (inner layer) has excellent skin-friendly properties, can absorb sweat and oil, and increases the comfort during wearing; it is especially suitable for occasions containing organic gases, acid volatiles, pesticides, SO2, Cl2 and other irritating gases, and has significant anti-virus and deodorizing effects.

[0143] From Figure 8 and Figure 9 it can be obtained that the concentrations of formaldehyde, benzene, toluene, xylene, styrene, chlorobenzene, hexene, hexane and tetrachloroethylene all show varying degrees of decrease after passing through the DOCTOR MASK activated carbon mask. The concentration decrease of benzene and hexane, these two compounds with relatively small molecular weights, is less than 10%, while the concentration decrease of compounds with relatively large molecular weights such as styrene, toluene, xylene and tetrachloroethylene is larger, all exceeding 15%; formaldehyde shows good adsorption on activated carbon, and the filtration efficiency can reach 86.48%; the presence of polar substituents will reduce the adsorption of compounds on activated carbon. Therefore, although chlorobenzene has a relatively large molecular weight, due to the different substituents, its concentration decrease is small, less than 4%; the DOCTOR MASK activated carbon mask has the worst filtration effect on hexene, and can hardly filter it, only 0.69%.

[0144] Step 2-5-2, Data of disposable mask

[0145] The disposable three-layer mask is made of two layers of non-woven fabric and filter paper. The nose bridge uses an environment-friendly all-plastic strip, which does not contain any metal, and is breathable and comfortable to wear. It is a mask that is worn more frequently in daily life.

[0146] From Figure 10 and Figure 11 it can be seen that the concentrations of various VOCs have all decreased. Among them, the concentration of formaldehyde has decreased by 15.36%, benzene has decreased by 23.28%, hexene has decreased by 18.29%, toluene has decreased by 20.01%, styrene has decreased by 27.61%, xylene has decreased by 22.16%, chlorobenzene has decreased by 6.63%, hexane has decreased by 17.88%, and tetrachloroethylene has decreased by 22.63%. This shows that wearing a disposable mask in normal life has a certain protective effect; however, its adsorption of halogenated aromatic chlorobenzene is relatively poor.

[0147] Step 2-5-3, Data of Reboo Mask

[0148] The Reboo mask is made of 82.9% polyester fiber and 17.1% spandex, known as ice silk fabric, and its main function is to provide sun protection and wind protection in summer.

[0149] From Figure 12 and Figure 13 it can be seen that the Reboo mask has a certain adsorption effect on the VOCs tested this time. Among them, the adsorption effects on benzene, toluene, styrene, xylene, chlorobenzene, and tetrachloroethylene are similar, and the concentration of several VOCs decreases by about 18% after passing through the mask; while the concentration decreases of hexene and hexane are very large, decreasing by 41.24% and 33.72% respectively; however, its adsorption effect on formaldehyde is relatively poor, only 3.95%.

[0150] Step 2-5-4, Data of Songyan KN95 Mask (with Exhalation Valve)

[0151] The Songyan KN95 mask (with exhalation valve) adopts a four-layer design of PP non-woven fabric, melt-blown filter cloth, primary filter cotton, and corn fiber cloth, and is equipped with an exhalation valve; it is suitable for environments with relatively large dust, as well as seasons with more influenza and pollen.

[0152] From Figure 14 and Figure 15 it can be seen that after several VOCs pass through the Songyan KN95 mask, only the concentrations of formaldehyde, benzene, and hexane have decreased. Among them, the adsorption effect of formaldehyde is relatively good, reaching 68.96%, while the concentrations of other several VOCs have not decreased significantly. Among them, for the two VOCs of styrene and xylene, their concentrations show a phenomenon of first decreasing briefly and then increasing after passing through the mask (the concentration decrease ratio is negative).

[0153] Step 2-5-5, Data of KN95 Protective Mask

[0154] The main materials of the KN95 protective mask are non-woven fabric and melt-blown cloth, meeting the GB2626-2006 KN95 standard. It is mainly used for preventing haze, droplets, and dust.

[0155] From Figure 16 and Figure 17 it can be obtained that the KN95 protective mask has a certain filtering effect on several tested VOCs; among them, the filtering effects of formaldehyde, toluene, styrene and xylene are better, and the concentrations have decreased by 62.27%, 52.6%, 32.67% and 44.10% respectively, while the concentrations of other several VOCs have only decreased by about 20%, but the concentration of chlorobenzene has only decreased by 10%.

[0156] Step 2-5-6, Data of 3200CN Gas Mask

[0157] The main body of the 3200CN gas mask is the 3200CN half mask, and there are different combinations when used in different occasions. In this test, VOCs are involved, so 3N11CN filter cotton (which can effectively filter paint mist generated in various painting operations), 3001CN / 3301CN organic vapor filter cartridges (which can effectively protect against organic gases and vapors) and 385CN filter cotton cover (to fix the pre-filter cotton) are used. This set of combination can be used for respiratory protection against paint mist and organic vapors generated during paint mixing and spraying processes.

[0158] From Figure 18 and Figure 19 it can be obtained that after several tested VOCs pass through the 3200CN gas mask, the concentrations decrease sharply. The concentration of formaldehyde has decreased by 99.08%, the concentration of benzene has decreased by 99.68%, the concentration of hexene has decreased by 98.51%, the concentration of toluene has decreased by 99.70%, the concentration of styrene has decreased by 99.82%, the concentration of xylene has decreased by 99.55%, the concentration of chlorobenzene has decreased by 99.56%, the concentration of hexane has decreased by 98.25%, and the concentration of tetrachloroethylene has decreased by 99.38%.

[0159] The comprehensive adsorption efficiency of this gas mask for different VOCs is as high as over 99%.

[0160] Step 2-6, Summarize data

[0161] The specific values of the concentration decrease range (%) of 9 VOCs after passing through the mask are shown in Table 5.

[0162] Table 5 Concentration Decrease Range (%) of 9 VOCs after Passing through the Mask

[0163]

[0164]

[0165] Step 3, Based on the data obtained from the test in Step 2, evaluate and analyze the existing respiratory protection products;

[0166] Among the data obtained in Step 2, in the decline rate of the concentration of 9 VOCs passing through each mask,

[0167] If the decline rate of each of the 9 data is below 35%, it is an extremely poor respiratory protection product;

[0168] If the decline rate of each of the 9 data is between 35% and 55%, it is a poor respiratory protection product;

[0169] If the decline rate of each of the 9 data is between 55% and 75%, it is a medium respiratory protection product;

[0170] If the decline rate of each of the 9 data is between 75% and 90%, it is an excellent respiratory protection product;

[0171] If the decline rate of each of the 9 data is between 90% and 100%, it is an extremely excellent respiratory protection product;

[0172] If only 1 - 2 of the 9 data have a decline rate higher than 35% and the decline rate of other data is lower than 35%, it is a poor respiratory protection product;

[0173] If 3 - 6 of the 9 data have a decline rate higher than 35% and the decline rate of other data is lower than 35%, it is a medium respiratory protection product;

[0174] If 6 - 9 of the 9 data have a decline rate higher than 35% and the decline rate of other data is lower than 35%, it is an excellent respiratory protection product;

[0175] If only 1 - 2 of the 9 data have a decline rate significantly higher than other data and the decline rate of other data is lower than 35%, it is a special respiratory protection product for this toxic and harmful gas;

[0176] From the data obtained in Step 2,

[0177] Among the DOCTOR MASK activated carbon masks, only 1 data (formaldehyde concentration) has a decline rate significantly higher than other data, which is 86.48%, and the decline rate of other data is lower than 35%, so it is a special respiratory protection product for formaldehyde;

[0178] Among the disposable masks, the decline rate of each of the 9 data is only below 35%, so it is an extremely poor respiratory protection product;

[0179] Among the Reboo masks, only 1 data (ethylene concentration) has a decline rate slightly higher than 35%, which is 41.24%, and the decline rate of other data is lower than 35%, so it is a poor respiratory protection product;

[0180] Among the Songyan KN95 masks, only 1 out of 9 data (formaldehyde concentration) shows a significantly higher decline rate after passing through than other data (68.96%), and the decline rates of other data are all lower than 35%. It is a special respiratory protection product for formaldehyde.

[0181] Among the KN95 protective masks, the decline rates of 3 out of 9 data (formaldehyde concentration, toluene concentration, xylene concentration) are higher than 35% (62.27%, 52.60%, 44.10% respectively), and the decline rates of other data are all lower than 35%. It is a medium respiratory protection product.

[0182] For the 3200CN gas mask, if the decline rate of each data among the 9 data is 90% - 100%, it is an excellent respiratory protection product.

[0183] Among the special respiratory protection products for formaldehyde, the protective effect of the Rebo mask is significantly lower than that of the DOCTOR MASK activated carbon mask.

[0184] It shows that among the 6 respiratory protection products to be evaluated in this embodiment, the 3200CN gas mask has the best protection performance (all above 99%). For firefighters who need to enter and exit the fire scene for inspection work, wearing a gas mask with an organic gas or vapor absorption filter cartridge during rescue can effectively reduce the threat of various toxic and harmful gases and particles in the fire scene air and protect the personal safety of firefighters. For other types of masks, although they have partial protection against VOCs, most VOCs will still leak and be inhaled by the human body. Therefore, they can only be used for anti-haze, anti-dust or sunscreen in daily life and are not suitable for use in fire scenes with high VOCs content.

[0185] Conduct actual effect tests on the gas masks and KN95 masks with relatively good data for wearing respiratory protection products.

[0186] Step 1: Gas sample collection

[0187] Take the exhaled breath of fire investigators before entering the scene for investigation and the exhaled breath after completing the on-site inspection as analysis samples. The age of the fire investigators is between 25 and 53. When sampling, the fire investigators just need to blow up the Tedlar sampling bag (1L or 3L).

[0188] Step 2: Sample analysis

[0189] Before mass spectrometry detection, first place the gas bag containing the sample gas in a vacuum drying oven and keep it at a constant temperature of 40°C for 1 hour, as Figure 4As shown, desorb the VOCs components adsorbed on the inner wall of the gas bag to prevent some VOCs components from being adsorbed on the inner wall of the gas bag during gas bag sampling and storage, resulting in loss of sample components and measurement errors.

[0190] Take out the gas bag, connect the gas bag to the HPPI-TOFMS injection port with a quick connector, and perform direct injection analysis. As Figure 5 shown, ensure that the entire detection is completed within 10 minutes at room temperature (20 ± 2 °C).

[0191] Detection conditions: The ionization region pressure is 450 Pa, the sampling and accumulation time for each spectrum is 30 s, each gas bag is detected in parallel three times, and finally the average value is taken.

[0192] Step 3: Detect the exhaled breath of healthy volunteers in a normal environment

[0193] The exhaled breath of healthy people in a normal environment was sampled and analyzed using HPPI-TOFMS technology, and 30 groups of exhaled breath of volunteers aged 20 - 35 were collected. Through analysis, some VOCs information was qualitatively determined as shown in Table 6. It can be seen from the table that in the exhaled breath of normal people, compounds such as acetone, ethanol, phenol, and isoprene were detected. Based on the characteristic ion pairs of these compounds, the mass spectrometry peaks in the exhaled breath of fire investigators were assigned to distinguish endogenous and exogenous VOCs.

[0194] Table 6 Detection results of VOCs in the exhaled breath of healthy volunteers

[0195]

[0196] Step 4: Detect the exhaled breath of fire investigators before and after entering the fire scene

[0197] The first group: At the fire scene of a residential building in Fushun on October 9, two investigators, Chen and Sun, both wore half-face gas masks and entered the fire scene for investigation;

[0198] Figure 20 and Figure 21 shown are the comparative spectrograms of the exhaled breath of fire investigators Chen and Sun before and after entering and leaving the fire scene (the spectrogram after leaving the fire scene is subtracted from the mass spectrogram before entering the fire scene).

[0199] It can be found from the spectrograms that there is not much difference in the exhaled breath of the two fire investigators before and after entering and leaving the fire scene. The spectrograms are relatively simple and there are few additional mass spectrometry peaks. Although the intensities of isoprene and butanone are relatively high, these substances are endogenous compounds present in the exhaled breath and are related to normal human metabolism, belonging to the normal fluctuation range.

[0200] It shows that the respiratory protection effect of the gas mask is good.

[0201] Group 2: At the fire scene of a restaurant in Fushun on November 2, fire investigators Zhang and Bao both wore KN95 masks and entered the fire scene for investigation;

[0202] Figure 22 and Figure 23 The following shows the comparative mass spectrometry of the exhaled breath of fire investigators Zhang and Bao before and after entering and leaving the fire scene (the spectrum after leaving the fire scene is subtracted from the mass spectrum before entering the fire scene).

[0203] As can be seen from the figure, in addition to VOCs such as ethanol, acetone, and butanone produced by normal breathing, toxic and harmful VOCs such as styrene and xylene were detected in the exhaled breath of both fire investigators. Therefore, it can be seen that when the two fire investigators were carrying out rescue work, they inhaled a certain amount of polluted gas at the fire scene.

[0204] This indicates that wearing a KN95 mask cannot effectively protect against toxic and harmful gases.

[0205] Result analysis: The protective effect of the gas mask is significantly higher than that of the KN95 mask, and the actual effect of the respiratory protection equipment is the same as the result obtained from the simulation experiment.

[0206] In summary, the technical solution of this patent realizes the high-throughput, high-sensitivity, and high-resolution online detection of trace complex components by online analyzing trace complex component toxic and harmful gases and human exhaled breath. The established effectiveness evaluation technology of respiratory protection equipment based on high-throughput mass spectrometry detection of trace complex components has the advantages of fast speed, high sensitivity, simplicity, and friendliness. The evaluation of the filtering effect of the respiratory protection equipment on trace toxic and harmful gases provides respiratory safety protection for fire investigation workers, and has significant economic and social benefits for scientific and effective protection and reduction of occupational hazards; the indicators are specific, applicable to the evaluation of various protection equipment, and have good applicability.

[0207] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations according to the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. A method for evaluating the protection of a fire breathing protection article, characterized in that, It includes the following steps: Step 1: Determine the gas components in the fire environment; determine the evaluation indexes of fire respiratory protection products according to the gas components in the fire environment; Step 2: Set up a respiratory protection product testing device to simulate the breathing process of a normal person wearing a respiratory protection product. Prepare a VOCs standard gas according to the gas components obtained in Step 1, simulate the fire scene environment, and conduct respiratory protection tests on each respiratory protection product to be evaluated; Monitor in real time and online the concentration change information of toxic and harmful gases in the simulated environment after passing through the respiratory protection product, and record the protection effect data of the respiratory protection product; The respiratory protection test includes Step 2-1: Fill a clean Tedlar gas bag with nitrogen, then use a syringe to extract a mixed gas from the Tedlar gas bag containing the mother gas and inject it into the Tedlar gas bag. Shake the gas bag and then let it stand for about 20 minutes to make the gas in the gas bag mix evenly. Finally, obtain a mixed gas of benzene, 1-hexene, toluene, styrene, xylene, chlorobenzene, n-hexane, and tetrachloroethylene; Step 2-2: Open the HPPI-TOFMS control software, load the test parameters, and wait for the instrument signal to stabilize; Connect the flow controller and the air pump with a capillary and a quick connector. Open the air pump and set the flow rate of the flow controller; Step 2-3: Connect the Tedlar gas bag directly to the HPPI-TOFMS injection capillary with a quick connector to detect the signal intensity of the mixed gas without passing through the mask; Step 2-4: Fix the respiratory protection product to be evaluated with a sealing and fixing device, connect the sealing and fixing device to the gas bag and the HPPI-TOFMS injection capillary with a quick connector, and detect the signal intensity of the mixed gas after passing through the respiratory protection product to be evaluated; Adopt the continuous monitoring mode, accumulate the signal intensity at each point for 30 s, stop the detection when the signal intensity of each respiratory protection product to be evaluated is stable, and detect two respiratory protection products to be evaluated in parallel for each type. When processing the data, take the average value of the data of the two respiratory protection products to be evaluated; At the same time, introduce nitric oxide molecules to promote the ionization of formaldehyde molecules. The ionization mechanism formula: NO + h γ = NO + + e - CH2O + NO+ = [CH2O]NO + Step 3: Evaluate and analyze the existing respiratory protection products based on the data obtained from the test in Step 2, and draw the evaluation conclusion of the fire respiratory protection products this time.

2. The protection evaluation method of the fire breathing protection articles according to claim 1, characterized in that In the said Step 1, The determination of the gas components in the fire environment includes collecting the gas in the fire scene environment and conducting HPPI-TOFMS analysis on the fire gas sample to obtain the types of VOCs gases remaining in the air in each fire scene.

3. The protection evaluation method of the fire breathing protection articles as described in claim 1, characterized in that, In the said Step 2, The respiratory protection equipment testing device includes a Tedlar gas bag, a sealing and fixing device, a mass spectrometer, a flow meter, and a suction pump; the Tedlar gas bag, the sealing and fixing device, the mass spectrometer, the flow meter, and the suction pump are connected in sequence; the suction pump is used to simulate the actual breathing flow of the human body; the sealing and fixing device includes two stainless steel cup-shaped jigs with their openings buckled together, clamping the respiratory protection equipment to be evaluated in the middle, and a rubber O-ring is arranged at the sealing surface of the opening of the cup-shaped jig to achieve sealing, avoiding the leakage of toxic and harmful sample gases and the influence of external environmental air penetration on the experiment; pipeline interfaces are arranged at the bottoms of both cup-shaped jigs, one end is connected to the air outlet of the Tedlar gas bag, and the other end is connected to the sampling capillary of the mass spectrometer and the suction pump through a three-way joint; The preparation of the VOCs standard gas includes the preparation of formaldehyde standard gas and the preparation of a mixed standard gas of 8 VOCs other than formaldehyde.

4. The protection evaluation method of the fire breathing protection articles according to claim 1, characterized in that In step 3, The evaluation and analysis criteria are as follows: among the concentration decline ranges of the 9 VOCs of each respiratory protection equipment to be evaluated after passing through the respiratory protection equipment to be evaluated, If the concentration decline range of each of the 9 data is below 35%, it is an extremely poor respiratory protection equipment; If the concentration decline range of each of the 9 data is 35% - 55%, it is a poor respiratory protection equipment; If the concentration decline range of each of the 9 data is 55% - 75%, it is a medium respiratory protection equipment; If the concentration decline range of each of the 9 data is 75% - 90%, it is an excellent respiratory protection equipment; If the concentration decline range of each of the 9 data is 90% - 100%, it is an extremely excellent respiratory protection equipment; If only 1 - 2 of the 9 data have a concentration decline range higher than 35% and the concentration decline ranges of the other data are all below 35%, it is a poor respiratory protection equipment; If 3 - 6 of the 9 data have a concentration decline range higher than 35% and the concentration decline ranges of the other data are all below 35%, it is a medium respiratory protection equipment; If 6 - 9 of the 9 data have a concentration decline range higher than 35% and the concentration decline ranges of the other data are all below 35%, it is an excellent respiratory protection equipment; If only 1 - 2 of the 9 data have a concentration decline range significantly higher than the other data and the concentration decline ranges of the other data are all below 35%, it is a special respiratory protection equipment for toxic and harmful gases.

5. The protection evaluation method of the fire breathing protection article according to claim 2, characterized in that In step 1, The types of VOCs in the fire scene gas are divided into 8 categories, namely ketones, olefins, alkanes, alcohols, aromatic hydrocarbons, esters, halogenated hydrocarbons, and others; the determined evaluation indicators include formaldehyde, benzene, hexene, toluene, styrene, xylene, chlorobenzene, hexane, and tetrachloroethylene.

6. The protection evaluation method of the fire breathing protection article according to claim 1, characterized in that In step 2, The respiratory protection equipment to be evaluated is a mask or a half-face gas mask.

7. The protection evaluation method of the fire breathing protection articles according to claim 1, characterized in that, In step 2, the respiratory protection equipment testing device for testing is actual fire investigators. The specific operation is to compare and analyze by detecting the components of the exhaled gas of the fire investigators before entering the fire scene and after leaving the fire scene respectively, obtain the types of residual VOCs gas in the exhaled gas of the fire investigators, and evaluate the protection effect of the protection equipment used by the fire investigators in this fire investigation.

8. The protection evaluation method of the fire breathing protection articles according to claim 7, characterized in that, Collect the types of residual VOCs in the exhaled gas of fire investigators and transmit them to a large database. Through the qualitative and quantitative analysis of the chemical components in the exhaled gas of investigators, a reliable evaluation of the health risks of fire investigators can be achieved.

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