Agent Name

FLUORIDES

Alternative Name

CLASS

Major Category

Other Classes

Synonyms

CLASSES; Fluorspar; Cryolite;

Category

Fluorides, Inorganic

Description

The main fluoride minerals are fluorspar (CaF2) and cryolite (Na3AlF6). [ACGIH]

Sources/Uses

Used in the primary production of aluminum, smelting operations (flux), welding (welding rods), and water treatment; [Levy, p. 409] Fluorosis was first recognized in the 1930s in factories processing cryolite. Today, occupational fluoride exposure occurs in factories manufacturing aluminum, glass, and fertilizer. Exposure also occurs in workers mining and processing cryolite, fluorspar, and apatite. [Rosenstock, p. 544] Used mainly as hydrogen fluoride to make fluoropolymers and hydrofluorocarbons; Also used as AlF3 to make aluminum, refined petroleum, herbicides, and uranium fluorides; The main sources of fluorides are diet, drinking water, and dentifrices; [ACGIH BEI]

Comments

50% of absorbed fluoride is excreted in urine within 24 hours; 99% of the remainder is taken up by bone with a 1/2 life of up to 8 years; tooth mottling is caused by 2-4 mg/day; skeletal changes are rare at 8 mg/day, but can be crippling at 20 to 80 mg/day; [Rosenstock, p. 544] Fluorides (inorganic, used in drinking water) are not classifiable as to carcinogenicity to humans. [IARC] The PEL and IDLH apply to sodium fluoride and other inorganic, solid fluorides. [NIOSH] Abnormal liver enzymes have been reported in cases of sodium fluoride toxicity. In acute poisoning cases, patients may have hyperactive reflexes and tetanic contractures from fluoride-induced hypocalemia and cardiac arrhythmias from hyperkalemia; Ingestion can cause hemorrhagic gastroenteritis; [HSDB] The TLV applies to inorganic fluorides; [ACGIH] In the US, no skeletal fluorosis observed after exposure to 4 mg/L in drinking water, but uptake of 20 mg/day for more than 20 years can cause skeletal fluorosis; Dental caries are reduced in adults after uptake of up to 4 mg/day; BEIs are not applicable to non-metal fluorides or organic compounds containing fluorine; [ACGIH BEI]

Exposure Assessment
BEI

Fluorides in urine = 2 mg/L prior to shift or 3 mg/L at end of shift; (Repeated measurements recommended.) [ACGIH]

Skin Designation (ACGIH)

Insufficient data

Bioaccumulates

Yes

TLV (ACGIH)

2.5 mg/m3, as F

PEL (OSHA)

2.5 mg/m3, as F

MAK

1 mg/m3, as F, inhalable fraction

IDLH (NIOSH)

250 mg/m3, as F

Excerpts from Documentation for IDLHs

"No data on acute inhalation toxicity are available on which to base the IDLH for fluorides. The chosen IDLH, therefore, has been estimated from the human acute lethal dose of 5 grams of sodium fluoride. . . . Skin rashes and complaints of the gastric, intestinal, circulatory, respiratory, and nervous systems have been reported in workers exposed chronically to concentrations ranging from 11 to 24 mg F/m3 " [NIOSH]

Explanatory Notes

"The BEIs are not applicable to non-metal fluorides and organic fluorine containing compounds. . . . Pre-shift sample measurement is an indicator of body burden and is significantly affected by environmental exposure." [ACGIH]

Half Life

Serum: 3-7 hours; [TDR, p. 706] 50% of absorbed fluoride is excreted in the urine within 24 hours. Of the remainder, 99% is absorbed in bone with a half-life of up to 8 years. [Rosenstock, p. 544]

Reference Link

ATSDR - ToxFAQs - Fluorine, Hydrogen Fluoride, and Fluorides

Adverse Effects
Hepatotoxin

Hepatotoxin, Secondary

IARC Carcinogen

Not Classifiable

ACGIH Carcinogen

Not Classifiable

Links to Other NLM Databases
Toxicity Information

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Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure:

Activities

Activities with risk of exposure: