ANTU

CAS number . . . . . . . . . . . 86-88-4
NIOSH REL. . . . . . . . . . . . 0.3 mg/m3 TWA
Current OSHA PEL . . . . . . . . 0.3 mg/m3 TWA
1989 OSHA PEL. . . . . . . . . . Same as current PEL
1993-1994 ACGIH TLV. . . . . . . 0.3 mg/m3 TWA
Description of substance . . . . White crystalline or gray, odorless powder.
LEL. . . . . . . . . . . . . . . Noncombustible Solid
Original (SCP) IDLH. . . . . . . 100 mg/m3
Basis for original (SCP) IDLH. . No useful acute inhalation toxicity data are
                                 available on which to base the IDLH for ANTU.
                                 The chosen IDLH, therefore, has been
                                 estimated from the fatal human oral dose of 1
                                 gram given by Stolman [1969].  According to
                                 ACGIH [1971], McClosky and Smith [1945]
                                 reported that the acute oral toxicity varies
                                 greatly among different species, with rats
                                 and dogs being the most susceptible (LD50 of
                                 30 to 50 mg/kg) and rabbits the least
                                 susceptible (LD50 of 1,000 mg/kg).
Short-term exposure guidelines . None developed

ACUTE TOXICITY DATA

Lethal dose data:

                                  LD50     LDLo                      Derived
Species     Reference     Route  (mg/kg)  (mg/kg)   Adjusted LD      Value
______________________________________________________________________________
Dog      AAPCO 1966       oral       0.38  -----       2.7 mg/m3     0.3 mg/m3
Rat      Lehman 1952      oral       6     -----      42   mg/m3     4.2 mg/m3
Monkey   Perkow 1971/76   oral   4,250     -----  29,750   mg/m3 2,975   mg/m3
Mouse    Yakkyoku 1977    oral       5     -----      35   mg/m3     3.5 mg/m3

Other animal data. . . . . . . . It has been reported that the mean oral
                                 lethal dose is 4,000 mg/kg in monkeys and is
                                 presumably much the same in man [Gosselin et
                                 al. 1984].
Human data . . . . . . . . . . . The fatal oral dose has been reported to be
                                 1,000 mg [Stolman  1969].  [Note:  An oral
                                 dose of 1,000 mg is equivalent to a worker
                                 being exposed to 650 mg/m3 for 30 minutes,
                                 assuming a breathing rate of 50 liters per
                                 minute and 100% absorption.]

Revised IDLH: 100 mg/m3 [Unchanged]
Basis for revised IDLH: No inhalation toxicity data are available on which to base an IDLH for ANTU. However, based on acute oral toxicity data in humans [Stolman 1969] and animals [Gosselin et al. 1984; Perkow 1971/76], the original IDLH for ANTU (100 mg/m3) is not being revised at this time.

REFERENCES:

1. AAPCO [1966]. Pesticide chemicals official compendium. Topeka, KS: Association of American Pesticide Control Officials, Inc., p. 57.
2. ACGIH [1971]. ANTU (alpha-naphthyl-thiourea). In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 15-16.
3. Gosselin RE, Smith RP, Hodge HC [1984]. Clinical toxicology of commercial products. 5th ed. Section III. Baltimore, MD: Williams and Wilkins Company, pp. 40-42.
4. Lehman AJ [1952]. Chemicals in foods: a report to the Association of Food and Drug Officials on current developments. Part II. Pesticides. Section III. Subacute and chronic toxicity. Q Bulletin Assoc Food Drug Off U.S. 16:47-53.
5. McClosky WT, Smith MI [1945]. Studies on the pharmacologic action and the pathology of alpha-naphthylthiourea (ANTU). I. Pharmacology. Public Health Rep 60(38):1101-1113.
6. Perkow W [1971/76]. Wirksubstanzen der pflanzenschutz und schadlingsbekampfungsmittel. Berlin, Germany: Verlag Paul Parey (in German).
7. Stolman A, ed. [1969]. Progress in chemical toxicology. Vol. 4. New York, NY: Academic Press, p. 235.
8. Yakkyoku (Pharmacy) [1977]; 28:329-335 (in Japanese).