TYPE OF AGENT – Smoke composition (pyrotechnic)
NAME (CHEMICAL) – Terephthalic Acid
NAME (COMMON) – TA
DATE OF DISCOVERY – 1846
MOLECULAR FORMULA – C8H6O4
MOLECULAR WEIGHT – 166.132 g/mol
PHYSICAL STATE @ 20° C. (68° F.) – Solid
FLASH POINT – 260° C. (500° F.)
MELTING POINT – 300° C. (572° F.)
BOILING POINT – Decomposes (Sublimes) @ 402° C. (756° F.)
SOLID DENSITY – 1.519 g/cc
VAPOR PRESSURE (mm/Hg) – 0.0000092 mm/Hg
APPEARANCE – White crystals or powder
SOLUBILITY – 0.065 g/L @ 25° C. (77° F.)
INHALATION TOXICITY – Irritating
SKIN TOXICITY – Irritating, causes surface redness
EYE TOXICITY – Irritating, causes redness
RATE OF ACTION – Rapid
SYMPTOMS (PHYSIOLOGICAL ACTION) – Cough, irritates skin and eyes
TREATMENT – Remove from exposure, wash affected areas
DURATION OF EFFECTIVENESS – Several minutes
PROTECTION – Gas mask, gloves
DECONTAMINATION – Remove contaminated clothes, wash and shower, wash area with water
USE – M83 Grenade
Burning compositions containing Terephthalic Acid as their active smoke-producing agent were developed for use during training as a replacement for the toxic HC smoke composition. Terephthalic Acid eliminates any exposure to toxic fumes from smoke, but the agent is much less effective than HC smoke. In general, it takes three M83 smoke grenades to produce a cloud close to being as dense as the older AN-M8 HC grenades, which are no longer produced. Though the M83 grenade loaded with Terephthalic Acid (TA) mixture has been adopted for combat use, research into smoke-producing compounds continues. TA can be mixed with 25 to 50% Granular Nitrocellulose, 10 to 25% Potassium Chlorate, 10 to 25% Sucrose, and 2.5 to 5% Manganese carbonate for use in burning-type munitions. The formulation employed by the US Military in the M83 Smoke Grenade is: by weight – 23% KCLO3, 14% Sucrose, 57% TA, 3% MgCO3, and 3% Stearic acid.
