Fluorides (as F)

CAS number: Varies

NIOSH REL: 2.5 mg/m³ TWA

Current OSHA PEL: 2.5 mg/m³ TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 2.5 mg/m³ TWA

Description of Substance: Varies

Original (SCP) IDLH: 500 mg F/m³

Basis for original (SCP) IDLH: 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 [Largent 1961 cited by AIHA 1965]. AIHA [1965] stated that the atmospheric concentration immediately hazardous to life is unknown, but "particulate fluorides are not likely to cause acute health problems among workmen unless large quantities are swallowed, or unless the more toxic decomposition products are involved. Exact concentrations producing immediate illness are unknown, but most likely are very high."

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA

Lethal concentration data:

Species	Reference	LC50	LCLo	Time	Adjusted 0.5-hr LC (CF)	Derived value
SiF4 Rat	Carpenter et al. 1949	-----	69,220 mg/m3	4 hr	101,071 mg F/m3	10,107 mg F/m3

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
CaF2 G. pig Rat	Budavari 1989 Vest Akad Med Nk 1977	oral oral	----- -----	>5,000 4,250	>17,051 mg F/m3 14,488 mg F/m3	>1,705 mg F/m3 1,449 mg F/m3
AlF6·3Na Rabbit	Largent 1948	oral	-----	9,000	34,208 mg F/m3	3,421 mg F/m3
F6Si·2Na Mouse Rabbit	Gig Tr Prof Zabol 1988 Sine 1993	oral oral	----- -----	70 125	297 mg F/m3 530 mg F/m3	30 mg F/m3 53 mg F/m3
F6Si·Mg·6H2O G. pig	Frear 1969	oral	200		581 mg F/m3	58 mg F/m3

Human data: 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 [Roholm 1937]. Chronic exposures at concentrations greater than 24 mg F/m³ have been considered to be "elevated" and a concentration of 10 mg F/m³ was considered "excessive" [Collings et al. 1952]. It has also been stated that the atmospheric concentration immediately hazardous to life is unknown, and particulate fluorides are not likely to cause acute health problems among workers unless large quantities are ingested; concentrations producing immediate illness are unknown, but most likely are very high [AIHA 1965]. It has been stated that 5 grams of sodium fluoride is the probable lethal oral dose [Largent 1961]. [Note: An oral dose of 5 grams is equivalent to a worker being exposed to about 1,500 mg F/m³ for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]

Revised IDLH: 250 mg F/m3 Basis for revised IDLH: The revised IDLH for fluorides is 250 mg F/m3 based on toxicity data in humans [AIHA 1965; Largent 1961; Roholm 1937]. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations above 250 mg F/m3.

REFERENCES:

1. AIHA [1965]. Fluoride-bearing dusts and fumes (inorganic). In: Hygienic guide series. Am Ind Hyg Assoc J 26:426-430.

2. Budavari S, ed. [1989]. 1669. Calcium fluoride. In: The merck index. 11th edition. Rahway, NJ: Merck & Co., Inc., p. 253.

3. Carpenter CP, Smyth HF Jr, Pozzani UC [1949]. The assay of acute vapor toxicity, and the grading and interpretation of results on 96 chemical compounds. J Ind Hyg Toxicol 31:343-346.

4. Collings GH, Fleming RBL, May R, Bianconi WO [1952]. Absorption and excretion of inhaled fluorides. AMA Arch Ind Hyg Occup Med 6:368-373.

5. Frear EH, ed. [1969]. Pesticide index. 4th ed. State College, PA: College Science Publishers, p. 265.

6. Gig Tr Prof Zabol [1988]; 53(11):80 (in Russian).

7. Largent EJ [1948]. The comparative toxicity of cryolite for rats and for rabbits. J Ind Hyg Toxicol 30:92-97.

8. Largent EJ [1961]. Fluorosis, the health aspects of fluorine compounds. Columbus, OH: Ohio State University Press.

9. Roholm K [1937]. Fluorine intoxication. A clinical hygiene study with a review of the literature and some experimental investigations. London, England: H.K. Lewis & Co.

10. Sine C, ed. [1993]. Safsan®. In: Farm chemicals handbook '93, p. C302.

11. Vest Akad Med Nk [1977]; 2:28-33 (in Russian).