why you must ground spray equipment to prevent ignition by a spark from static electricity.
(3) Vapor concentration and flash points in enclosed spaces. Solvent vapors, which are
heavier than air, will move along the ground for dozens of yards from the area of application. For this
reason, you must extinguish all flames anywhere near the painting area. The flash points and flammable
vapor/air limits of common paint solvents are given in Appendix D.
b. Oil-Based Paints. Many exterior paints for wood and steel are based on raw or refined
linseed oil. These represent a very definite fire hazard if you allow paint-soaked waste or wiping rags to
remain lying around. As the paint dries, the oxidation of the oil can cause the temperature to rise to the
point where the rag or waste material will ignite spontaneously. The situation is especially dangerous if
rags are contaminated with pure raw or boiled linseed oil (Figure 1-21).
c. Other Paints. The majority of paints that you apply on site contain high-flashing solvents
(over 100€F); therefore, they are relatively low in hazard and require only normal precautions.
However, some finishes represent an abnormal fire and explosion hazard. Among these are spray
finishes with low- flashing solvents as described above. Others are nitrocellulose lacquers that burn
rapidly because of the nitrocellulose present and two-component products that are subject to
spontaneous combustion if mixed in large quantities.
Figure 1-21. Keep combustibles stored in tightly covered, metal waste cans
Precautions and Prevention.
You, as the supervisor, must ensure that certain general safety rules regarding fire and explosion hazards
are applied to all situations.