MIL-HDBK-1110
concentrations are very low, they are expressed as parts of vapor
per million parts of air by volume (ppm). The higher the value,
the safer the solvent.
3.2.4
Hazardous Air Pollutants. Some solvents currently used
in coatings are on the list of hazardous air pollutants of the
Clean Air Act. Restrictions on the use of some of these solvents
in coatings are expected. Also, halogenated solvents currently
exempted from VOC restrictions because of their photo-chemical
inactivity, may be eliminated from use in coatings in the near
future because they deplete the upper atmosphere ozone layer. In
addition, halogenated solvents can become explosive when in
contact with aluminum spray guns.
3.2.5
Binders - Polyurethanes, Coal Tars, Asphalts. Coatings
formulated with these resins may required special worker safety
measures. Respirators and protective clothing may be needed.
The material safety data sheet and the installations health and
safety office should be consulted.
3.2.6
Heavy Metal-Containing Pigments and Additives. Lead-
and chromate-containing pigments have been used in paints to
provide color and corrosion control. Because of health concerns,
a Federal regulation limits lead concentration in new consumer
paints to less than 0.06 percent of the weight of the paint
solids. Although chromium, as chromate, is not specifically
excluded from paints by Federal regulation, the military guide
specifications for painting facilities (NFGS-09900, Paints and
Coatings and CEGS 09900, Painting, General) exclude chromate-
containing coatings. Chromate is also on the ACGIH list of
suspected carcinogens. Mercury-containing additives have been
used to provide in-can bacteria control and paint-film mildew
control. Because of health concerns, mercury can no longer be
used in paints for residential use. Organic materials are used
to control bacterial growth in the can and mildew growth on
films.
Organo-tins have been used to control fouling on paints
exposed to sea water. Because of the toxic effects of these
materials, they have been restricted by the EPA. Copper-
containing and some organic materials are being used to provide
this protection.
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