Air Monitoring Applications - Paints & Coatings

Paints & Coatings - Pigments

Paint pigments have been around since prehistoric early artwork and have evolved to what they are today. Pigments come in a variety of types from those that are naturally occurring mineral-based (iron oxide, clay-based, carbon black, zinc, etc) to the synthesized pigments of today. The earliest synthetic pigments contained lead (white) and copper silicate (Egyptian blue). As other synthetic pigment colors were created, cadmium and chromium became popular.


Types of Pigments:
Lead-Based
Chromium-Based
Cadmium Based

Air Sampling Media by Regulatory Method
Method Contaminants of Interest Sampling Media
OSHA
OSHA ID 103 Chromic Acid and Chromates (Hexavalent Chromium) Filter- PVC (23387)
OSHA ID 121 Metal and Metalloid Particulates (Pb, Cr, & Cd) Filter – MCE (23381)
OSHA ID 125G Metal and Metalloid Particulates (Pb, Cr, & Cd) Filter – MCE (23381)
OSHA ID 189 Cadmium Filter – MCE (23381)
NIOSH
NIOSH 7024 Chromium and Compounds Filter – MCE (23381)
NIOSH 7048 Cadmium and Compounds Filter – MCE (23381)
NIOSH 7300 Elements (Pb, Cd, & Cr) Filter – MCE (23381)
NIOSH 7600 Chromium Hexavalent (Chromic Acid and Chromates) Filter- PVC (23387)
NIOSH 7604 Chromium Hexavalent (Chromic Acid and Chromates) Filter- PVC (23387)
NIOSH 7605 Chromium Hexavalent by ICP Filter- PVC (23387)

Lead-Based Pigments back to top

The US Consumer Product Safety Commission banned lead-based paints for use in the US in 1978 (16 Code of Federal Regulations CFR 1303). The European Union followed with a ban in 1992.
Lead poisoning is the leading environmentally induced illness in children under the age of six because of their rapid physiological and neurological development. The most common source of lead-poisoning is from degradation of lead-based paint in the home; additional sources include contaminated dust from ambient sources such as motor vehicles and industrial emissions, contaminated soils, and drinking water from plumbing materials.

Today, lead-based paint and motor vehicle emmissions are no longer the leading sources of lead pollution in air, but industrial sources are the primary cause. The highest level of lead emissions comes from lead-smelting industries, waste incineration, utilities, and lead-acid battery manufacturers.

Exposure Limits
Agency Exposure Limit
Lead
OSHA (PEL) for General Industry: 0.05 mg/m³ TWA; 0.03 mg/m³ Action Level
for Construction Industry: 0.05 mg/m³ TWA; 0.03 mg/m³ Action Level
for Maritime: 0.05 mg/m³ TWA; 0.03 mg/m³ Action Level
ACGIH (TLV) 0.05 mg/m³ TWA; Appendix A3 - Confirmed Animal Carcinogen w/ Unknown Relevance to Humans
NIOSH (REL) 0.050 mg/m³ TWA; Appendix C - Supplementary Exposure Limits (Air concentrations should be maintained so that worker blood lead remains less than 0.060 mg Pb/100 g of whole blood.)
NIOSH (IDHL) 100 mg/m³ as Pb
(TWA=Time-weighted average; TLV=Threshold Limit Value; PEL=Personal Exposure Limit, REL=Recommended Exposure Limit; IDHL=Immediately Dangerous to Life and Health concentration)

References
NIOSH Pocket Guide – Lead
OSHA – Lead Standard
EPA Air Toxics – Lead


Chromium-Based Pigments back to top

Primer paint containing hexavalent chromium is still widely used for aerospace and automobile refinishing applications. Zinc chromate has been used as a pigment for artists paint, known as Zinc Yellow or Yellow 36. It is highly toxic and now rarely used. Exposure may result in respiratory ailments.

Exposure Limits
Agency Exposure Limit
Chromium
OSHA (PEL) for General Industry: 1.0 mg/m³
for Construction Industry: 1.0 mg/m³ TWA
for Maritime: 1.0 mg/m³ TWA
ACGIH (TLV) 0.5 mg/m³ TWA
NIOSH (REL) 0.5 mg/m³ TWA
(TWA=Time-weighted average; TLV=Threshold Limit Value; PEL=Personal Exposure Limit, REL=Recommended Exposure Limit

Hexavalent Chromium
Exposure to hexavalent chromium occurs mainly among workers who handle pigments containing dry chromate, spray paints and coatings containing chromate, operate chrome plating baths, and weld or cut metals containing chromium, such as stainless steel. Workers who inhale these compounds at their jobs over many years may be at increased risk of developing lung cancer. Breathing high levels can irritate or damage the nose, throat, and lungs. Irritation or damage to the eyes and skin can occur if it contacts these organs in high concentrations or for a prolonged period of time.

Exposure Limits
Agency Exposure Limit
Hexavalent chromium
OSHA (PEL) for General Industry: 29 CFR 1910.1000 Z-1 Table -- 29 CFR 1910.1026 0.005 mg/m³ or 5 mg/m³ TWA; 0.0025 mg/m³ or 2.5 g/m³ Action Level; 0.025 mg/m³ or 25 mg/m³ TWA (Painting of aerospace industry's aircraft or large aircraft parts).
NOTE: Applies to all occupational exposures to Chromium (VI) except application of pesticides regulated by the Environmental Protection Agency or another Federal government agency (e.g., the treatment of wood with preservatives); portland cement; or where the employer has objective data demonstrating that a material containing chromium or a specific process, operation, or activity involving chromium cannot release dusts, fumes, or mists of chromium (VI) in concentrations at or above 0.5 µg/m³ as a TWA under any expected conditions of use.
for Construction Industry: 29 CFR 1926.55 Appendix A -- 29 CFR 1926.1126; follows same PEL’s
for Maritime: 29 CFR 1915.1000 Table Z-Shipyards -- 29 CFR 1915.1026; follows same PEL’s
ACGIH (TLV) Metal and Cr(III) cmpds, as Cr, 0.5 mg/m³ TWA, Appendix A4 - Not Classifiable as a Human Carcinogen; Water-Soluble Cr(VI) cmpds, as Cr, 0.05 mg/m³ TWA, Appendix A1 - Confirmed Human Carcinogen; Insoluble Cr(VI) cmpds, as Cr, 0.01 mg/m³ TWA, Appendix A1 - Confirmed Human Carcinogen; Strontium Chromate, as Cr, 0.0005 mg/m³ TWA, Appendix A2 - Suspected Human Carcinogen
NIOSH (REL) 0.001 mg Cr(VI)/m³ 10-hr TWA; Carcinogenic; Appendix A - NIOSH Potential Occupational Carcinogens; Appendix C - Supplementary Exposure Limits
NIOSH (IDHL) 15 mg/m³ as Cr(VI)
(TWA=Time-weighted average; TLV=Threshold Limit Value; PEL=Personal Exposure Limit, REL=Recommended Exposure Limit

References
OSHA Safety and Health Topics – Hexavalent Chromium
EPA Air Toxics Website – Chromium Compounds
NIOSH Pocket Guide – Chromic Acid and Chromates


Cadmium-Based Pigments back to top

Cadmium is found in some industrial paints and may present a hazard when spraying applications are employed, additional risks are possible when removing cadmium based paints by scraping or blasting methods.

The most common uses for cadmium are ore smelting, electroplating and some types of batteries. Cadmium emits a characteristic brown fume (CdO) when heated, which is relatively non-irritating, and thus does not alarm the exposed individual. Several deaths from acute exposure have occurred among welders who have unsuspectingly welded on cadmium-containing alloys or worked with silver solders.


Exposure Limits
Agency Exposure Limit
Cadmium
OSHA (PEL) for General Industry: 5 µg/m³ TWA; 2.5 µg/m³ Action Level
for Construction Industry: 5 µg/m³ TWA; 2.5 µg/m³ Action Level
for Maritime: 5 µg/m³ TWA; 2.5 µg/m³ Action Level
ACGIH (TLV) 0.01 mg/m³ TWA; 0.002 mg/m³ - Respirable Fraction TWA;
Appendix A2 - Suspected Human Carcinogen
NIOSH (REL) Appendix A - NIOSH Potential Occupational Carcinogens;
REL applies to all Cadmium compounds (as Cd)
(TWA=Time-weighted average; TLV=Threshold Limit Value; PEL=Personal Exposure Limit, REL=Recommended Exposure Limit; IDHL=Immediately Dangerous to Life and Health concentration)