A flame retardant, intumescent pressure sensitive adhesive (PSA) composition for EMI shielding gaskets, tapes, wraps, and the like. The composition is formulated as an admixture of: (a) a PSA component; (b) a halogenated first flame retardant component; (c) a metal-based second flame retardant component; and (d) a filler component of expandable, intercalated graphite particles. In a representative embodiment the PSA component (a) is acrylic-based, the halogenated first flame retardant component (b) is a polybrominated diphenyl compound such as decabromodiphenyl oxide or decabromodiphenyl ether, the metal oxide-based second flame retardant component (c) is antimony oxide, antimony trioxide, or antimony pentoxide, and the filler component (d) is graphite flake.