MIL-HDBK-1110
5.20.1
Painted Markings. Military airfields and roadways have
been successfully marked with alkyd paints for many years.
Chlorinated rubber was added to the alkyd resin to obtain faster
drying times. More recently, environmental restrictions on total
paint solvent have in many geographical locations eliminated or
restricted the use of these marking paints. Thus, most pavements
at military activities are marked with latex paints today.
Yellow marking paints constitute a possible safety and
environmental problem. Historically, a lead chromate pigment has
been used to impart this color because it is relatively light,
stable, and inexpensive. Lead pigments were recently restricted
from use in consumer paints because of concerns that dust from
weathering paints might be ingested by children. More recently,
concern has been expressed about the hazards of chromate
pigments. New regulations impose restrictions on the removal of
old paints containing lead and chromium because of possible
adverse health effects the dust produced may have on workers or
residents in the area. Also, residues of lead and chromate-
containing paints may constitute hazardous waste which must be
specially handled, stored, and disposed of properly. This has
lead to the virtual elimination of lead and chromium constituents
in paint. The State of California Department of Transportation
and other state highway departments have had good success with
yellow striping paints with organic pigments that do not
constitute a health or environmental hazard.
5.20.1.1 Specifications for Marking Paints. Currently, there
are five federal specifications for marking paints.
Specification TT-P-85, Paint, Traffic and Airfield Marking,
Solvent Base is for a solvent-based traffic and airfield marking
paint, available in white and yellow. Alkyd formulations have
generally been used, even though no specific generic type is
required. Paints of this specification are high in VOCs and so
cannot be used in areas where such paints are prohibited (urban
areas with air pollution). Water-based marking paints conforming
to TT-P-1952 are used in such areas, as well as in areas without
such restrictions.
a) Specification TT-P-87, Paint: Traffic, Premixed,
Reflectorized is for a premixed, solvent-based, reflectorized
traffic paint, available in white and yellow. Low index of
refraction (road) beads are premixed with the paint before
packaging. The embedded beads are reported to be exposed as
vehicular traffic erodes away the marking. They are not suitable
for use on airfields because of the low index of refraction
beads.
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