MIL-HDBK-1110
Table 3 (Continued)
TLV and Other Safety Data on Paint and Cleaning Solvents
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NOTES: (1) Relative evaporation time is the relative time
required for the solvent to completely evaporate, based on an
arbitrary value of 1.0 for ethyl ether. The higher the number,
the longer the time required for evaporation.
(2) Flash point is the temperature of the solvent in
degrees F at which the solvent releases sufficient vapor to
ignite in the presence of a flame. The higher the value, the
safer the solvent with respect to flash point.
(3) Explosive limits define the range of solvent vapor
concentration in air for which the vapor could explode or ignite.
Below the minimum concentration and above the maximum
concentration, the vapor will not ignite. These values are
expressed as the percentage of the solvent vapor in the total
volume of vapor plus air. They are also called flammable limits.
(4) Threshold limit values (TLV) were obtained from the
American Conference of Governmental Industrial Hygienists
(ACGIH), Threshold Limit Values for Chemical Substances and
Physical Agents in the Workroom Environment. TWA is the time
weighted average exposure limit for an 8-hour workday or a 40
hour week. STEL is the short-term exposure limit for a maximum
15-minute exposure. Both values are expressed as parts per
million (ppm) of vapor per volume of air. The higher the value,
the safer the solvent. These TLV's are ACGIH's recommendations;
Occupational Safety and Health Administration (OSHA) limits may
be lower.
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3.3
Issues Affecting Surface Preparation
3.3.1
Regulations. This section is aimed at environmental
issues. Worker safety issues are discussed in Section 13.
Environmental concerns and regulations affecting surface
preparation activities involve contamination of the environment
and waste disposal. Air regulations (National Ambient Air
Quality Standards described in 40 CFR 50-99) that are closely
associated with surface preparation and paint removal are the
ones for air particulate matter (PM 10) and lead. Air
particulate matter is defined as particles with an aerodynamic
diameter less than a nominal 10 micrometers. The allowable limit
is 150 milligrams per cubic meter, based on a 24-hour average
concentration. For lead, the criterion is 1.5 milligrams per
cubic meter, based on a 90-day average. Exceeding the PM 10
criterion is more likely during abrasive blasting than other
coating operations.
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