The dichlorophenyl isocyanates are combustible, crystalline (sugar or sand-like) solids. In general, they
are white to yellow in color, but the 1,4-dichloro-2-phenyl
isomer is white to light green. Their flash points are
generally .113C but that of the 1,3-dichloro-2-phenyl isomer is reported as 77C. These chemicals are insoluble in
water, and some may be reactive. 1,2-dichloro-4-isomer
(CAS 102-36-3) is the isomer of regulatory focus
May form explosive mixture with air.
Isocyanates are highly flammable and reactive with many
compounds, even with themselves. Incompatible with
oxidizers (chlorates, nitrates, peroxides, permanganates,
perchlorates, chlorine, bromine, fluorine, etc.); contact may
cause fires or explosions. Reaction with moist air, water or
alcohols may form amines and insoluble polyureas and
react exothermically, releasing toxic, corrosive or flammable gases, including carbon dioxide; and, at the same time,
may generate a violent release of heat increasing theconcentration of fumes in the air. Incompatible with
amines, aldehydes, alkali metals, ammonia, carboxylic
acids, caprolactum, alkaline materials, glycols, ketones,
mercaptans, hydrides, organotin catalysts, phenols, strong
acids, strong bases, strong reducing agents such as
hydrides, urethanes, and ureas. Elevated temperatures or
contact with acids, bases, tertiary amines, and acylchlorides may cause explosive polymerization. Contact
with metals may evolve flammable hydrogen gas. Attacks
some plastics, rubber, and coatings.
