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May 1994

Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)


CAS number: 98–95–3

NIOSH REL: 1 ppm (5 mg/m3) TWA [skin]

Current OSHA PEL: 1 ppm (5 mg/m3) TWA [skin]

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 1 ppm (5 mg/m3) TWA [skin]

Description of substance: Yellow, oily liquid with a pungent odor like paste shoe polish.

LEL(@200°F): 1.8% (10% LEL(@200°), 1,800 ppm)

Original (SCP) IDLH: 200 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by ACGIH [1971] and AIHA [1959] that Henderson and Haggard [1943] reported that 200 ppm is the maximum concentration that can be inhaled for 1 hour without serious disturbance.

Short-term exposure guidelines: None developed


Lethal dose data:


SpeciesReferenceRouteLD50 (mg/kg)LDLo (mg/kg)Adjusted LDDerived value
DogFlury and Zernik 1935 oral-----7501,025 ppm103 ppm
RatKashkalda &d Kolodub 1988 oral780-----1,066 ppm107 ppm
RatSmyth et al. 1969 oral600-----820 ppm82 ppm
MouseVasilenko & Zvezdai 1981 oral590-----807 ppm 81 ppm

Human data: It has been reported that 200 ppm is the maximum concentration that can be inhaled for 1 hour without serious disturbance [Henderson and Haggard 1943].


Revised IDLH: 200 ppm [Unchanged]

Basis for revised IDLH: Based on acute inhalation toxicity data in humans [Henderson and Haggard 1943], the original IDLH for nitrobenzene (200 ppm) is not being revised at this time.


1. ACGIH [1971]. Nitrobenzene. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 183.

2. AIHA [1959]. Nitrobenzene. In: Hygienic guide series. Am Ind Hyg Assoc J 20:66-67.

3. Flury F, Zernik F [1935]. Zusammenstellung der toxischen und letalen dosen für die gebräuchlichsten gifte und versuchstiere. Abder Hand Biol Arbeitsmethod 4:1289-1422 (in German).

4. Henderson Y, Haggard HW [1943]. Noxious gases. 2nd ed. New York, NY: Reinhold Publishing Corporation, p. 228.

5. Kashkalda DA, Kolodub FA [1988]. Effect of para-nitrobenzol and 2,4-dinitrochlorobenzol on condition of hydrocarbon-energetic exchange in rats. Gig Tr Prof Zabol 32(2):48-49 (in Russian).

6. Smyth HF Jr, Weil CS, West JS, Carpenter CP [1969]. An exploration of joint toxic action: twenty-seven industrial chemicals intubated in rats in all possible pairs. Toxicol Appl Pharmacol 14:340-347.

7. Vasilenko NM, Zvezdai VI [1981]. Mathematical prognosing of toxicity data for nitro and amino compounds having a benzene ring. Gig Tr Prof Zabol 25(8):50-52 (in Russian).

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