Agent Name |
Lead |
CAS Number |
7439-92-1 |
Formula |
Pb |
Major Category |
Metals |
Synonyms |
Plumbum; [NIOSH] |
Category |
Elements, Metallic |
Description |
A heavy, ductile, soft, gray solid; Inorganic lead includes lead oxides, metallic lead, and lead salts (including organic salts such as lead soaps but excluding lead arsenate). [NIOSH] |
Sources/Uses |
MINING OR SMELTING: Produce lead fume by primary or secondary smelting--includes brass, copper, and lead foundries and scrap metal recycling operations; MANUFACTURING: Lead-acid battery; crystal glass; lead joints/babbitt; pewter; fishing weights; leaded or stained glass; paint and ink; leaded plastics; ammunition; electronic components (ceramic coated capacitors and resistors); electrical components using fritted glass; lead pipe, sheet, solder, type metal, cable shielding, or anodes; ceramics (mix glaze & fire kiln); mix and weigh lead powders; USING: Weld, cut, braze, grind, sand or blast old paint: houses and buildings (painted before 1978); bridges; ships; steel towers; water, petroleum or underground tanks; Produce lead fume or dust by heating, machining, or spraying lead products; radiator repair; firing ranges; In a 2003 survey of industries using lead in New Jersey, 83% of lead was used to make automotive batteries. The second highest use was metal production (primary and scrap recycling). The third was cable and wire production. The fourth was making leaded compounds in plastics, pastes, and caulks. [PMID 17558800] |
Comments |
At blood lead levels above 90 ug/dl, poisoning can cause acute lead encephalopathy. Peripheral neuropathy results from levels above 60 ug/dl, and nerve conduction delays have been measured at levels as low as 30 ug/dl. [ACGIH: BEI Documentation] Exposure to high air concentrations of lead can precipitate hemolytic anemia. [LaDou, p. 217] At blood levels above 50-60 ug/dl, suppression of heme synthesis causes anemia. [Rom, p. 978] Lead-exposed workers may develop proximal renal tubular damage and progressive renal insufficiency. [Rom, p. 966] Lead can produce slight hepatic injury in experimental animals. [Zimmerman, p. 419] There is strong positive data associating lead exposure with spontaneous abortions and prematurity in pregnant women, neurological dysfunction in children and decreased sperm counts in men. [ATSDR Case Studies #29] The OSHA standard requires periodic determination of blood lead in workers exposed at or above action level (30 ug/m3) for more than 30 days per year. [ATSDR ToxProfiles] About 90% of pre-1940 homes contain lead-based paints, while about 60% of 1960-1979 homes contain significant amounts of lead in paint. The use of lead piping and lead solder in plumbing has been prohibited since 1986. [Coluccio VM. Lead-Based Paint Hazards. Wiley, John & Sons; 1997, p. 8-15] Inorganic lead compounds are probable human carcinogens. Organic lead compounds are not classifiable. [IARC] In contrast to inorganic lead, organic compounds are absorbed readily through the skin and into the CNS. [Sullivan, p. 979] Tetraethyl & tetramethyl lead (CAS # 78-00-2 & 75-74-1) are covered separately. |
Restricted |
Organic lead was added to gasoline in the US until January 1996. Lead allowable in US paint was reduced to 1% in 1971 and to 0.006% in 1977. [ATSDR Case Studies, Lead Toxicity] |
Reference Link |
ATSDR - Index, Lead Toxicity Case Study |
Exposure Assessment |
BEI |
Lead in blood = 30 ug/100 ml; sampling time not critical; |
Skin Designation (ACGIH) |
No |
Bioaccumulates |
Yes |
TLV (ACGIH) |
0.05 mg/m3 |
PEL (OSHA) |
0.05 mg/m3 |
MAK |
0.1 mg/m3, inhalable fraction |
IDLH (NIOSH) |
100 mg/m3 |
Excerpts from Documentation for IDLHs |
Basis for revised IDLH: No inhalation toxicity data are available on which to base an IDLH for lead compounds. |
Explanatory Notes |
Melting Point = 621 degrees F; |
Half Life |
Blood: 1-3 months; whole body: 5 years; [TDR, p. 790] |
Reference Link |
ATSDR - ToxFAQs - Lead |
Adverse Effects |
Anemia |
Anemia, Hemolytic |
Neurotoxin |
Motor Neuropathy |
Hepatotoxin |
Hepatotoxin, Secondary |
Nephrotoxin |
Yes |
Reproductive Toxin |
Yes |
IARC Carcinogen |
Probable Carcinogen |
Links to Other NLM Databases |
Health Studies |
Human Health Effects from Hazardous Substances Data Bank: LEAD, ELEMENTAL
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