Arsenic (inorganic compounds, as As)

CAS number . . . . . . . . . . . 7440-38-2 (Metal)
NIOSH REL. . . . . . . . . . . . 0.002 mg As/m3 15-minute CEILING; NIOSH
                                 considers inorganic arsenic compounds to be
                                 potential occupational carcinogens as
                                 defined by the OSHA carcinogen policy [29 CFR
                                 1990].
Current OSHA PEL . . . . . . . . 0.010 mg As/m3 TWA
1989 OSHA PEL. . . . . . . . . . Same as current PEL
1993-1994 ACGIH TLV. . . . . . . 0.01 mg As/m3 TWA, A1
Description of substance . . . . Varies
Original (SCP) IDLH. . . . . . . 100 mg As/m3
Basis for original (SCP) IDLH. . The chosen IDLH is based on the cat 1-hour
                                 LCLO of 100 mg/m3 for arsenic trichloride
                                 [Flury 1921 cited by NIOSH 1976].
Short-term exposure guidelines . None developed

ACUTE TOXICITY DATA

Lethal concentration data:

                                                   Adjusted               
                                                    0.5-hr           Derived
Species  Reference   LC50      LCLo    Time         LC (CF)           Value
______________________________________________________________________________
AsCl3
 Cat    Flury 1921   -----  100 mg/m3  1 hr   52 mg As/m3 (1.25)  5.2 mg As/m3
 Cat    Spector      -----  200 mg/m3 20 min  79 mg As/m3 (0.96)  7.9 mg As/m3
        1955
 Mouse  Spector      -----  338 ppm   10 min 726 mg As/m3 (0.69) 73   mg As/m3
        1955

Lethal dose data:


                                                                              
                                 LD50    LDLo                         Derived
Species     Reference    Route (mg/kg) (mg/kg)     Adjusted LD         Value
______________________________________________________________________________
As
 Rat     Davydova et al. oral    763    -----   5,341 mg As/m3  534   mg As/m3
         1987
 Mouse   Davydova et al. oral    145    -----   1,015 mg As/m3  102   mg As/m3
         1987
Ca3(AsO4)2
 Rat     Lehman 1951     oral     20    -----      53 mg As/m3    5.3 mg As/m3
 Mouse   MacEwen and     oral    794    -----   2,090 mg As/m3  209   mg As/m3
         Vernot 1972
 Rabbit  Muehlberger     oral     50    -----     132 mg As/m3   13   mg As/m3
         1930
 Dog     Perkow 1971/    oral     38    -----     100 mg As/m3   10   mg As/m3
         1976
Pb3(AsO4)2
 Rabbit  Muehlberger     oral     75    -----      88 mg As/m3    8.8 mg As/m3
         1930

Human data . . . . . . . . . . . None relevant for use in determining the
                                 revised IDLH.

Revised IDLH: 5 mg As/m3
Basis for revised IDLH: The revised IDLH for inorganic arsenic compounds is 5 mg As/m3 based on acute inhalation toxicity data in animals [Flury 1921; Spector 1955]. This may be a conservative value due to the lack of relevant acute toxicity data for workers. [Note: NIOSH recommends as part of its carcinogen policy that the "most protective" respirators be worn for inorganic arsenic compounds at concentrations above 0.002 mg As/m3. OSHA currently requires in 29 CFR 1919.1018 that workers be provided with and required to wear and use the "most protective" respirators in concentrations exceeding 20 mg As/m3 (i.e., 2,000 x the PEL).]

REFERENCES:

1. Davydova VE, Neizuestnova EM, et al. [1987]. Toxicity of metallic arsenic. Gig Tr Prof Zabol 31(12):58 (in Russian).
2. Flury F [1921]. Arsentrichlorid. In: Uber kampfgasvergiftungen. IX. Lokal reizende arsenverbindungen. Zeit Ges Exp Med 13:527-528 (in German).
3. Lehman AJ [1951]. Chemicals in foods: a report to the Association of Food and Drug Officials on current developments. Part II. Pesticides. Q Bulletin Assoc Food Drug Off U.S. 15(4):122-125.
4. MacEwen JD, Vernot EH [1972]. Toxic Hazards Research Unit annual technical report: 1972. Wright-Patterson Air Force Base, OH: Aerospace Medical Research Laboratory, Report AMRL-TR-72-62.
5. Muehlberger CW [1930]. Toxicity studies of fluorine insecticides. J Pharmacol Exp Ther 39:246-248.
6. NIOSH [1976]. CG17500. Arsenic chloride. In: Registry of toxic effects of chemical substances (RTECS) 1976 ed. Cincinnati, OH: U.S. Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication No. 76-191, p. 126.
7. Perkow W [1971/1976]. Wirksubstanzen der Pflanzenschytz and Schadlingsbekampfungsmittel. Berlin, Germany: Verlag Paul Parey (in German).
8. Spector WS, ed. [1955]. Handbook of toxicology. Vol. 1. Acute toxicities of solids, liquids and gases to laboratory animals. Philadelphia, PA: W.B. Saunders Co., pp. 324-325.