May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)

CAS number: 100–01–6

NIOSH REL: 3 mg/m3 TWA [skin]

Current OSHA PEL: 6 mg/m3 (1 ppm) TWA [skin]

1989 OSHA PEL: 3 mg/m3 TWA [skin]

1993-1994 ACGIH TLV: 3 mg/m3 TWA [skin]

Description of substance: Bright yellow, crystalline powder with a slight ammonia-like odor.

LEL: . . . Unknown

Original (SCP) IDLH: 300 mg/m3

Basis for original (SCP) IDLH: The chosen IDLH (300 mg/m3 or 50 ppm) is based on an analogy with aniline and the statement by AIHA [1955] that 50 to 100 ppm aniline can probably be tolerated for 1 hour. Although the IDLH chosen for aniline was 100 ppm, the IDLH of 50 ppm (300 mg/m3) chosen for p-nitroaniline is reasonable because Von Oettingen [1941] stated that p-nitroaniline is more toxic than aniline.

Short-term exposure guidelines: None developed


Lethal dose data:

Species Reference Route LD50




Adjusted LD Derived value


G. pig


Back et al. 1972

Matrka et al. 1978

Moskalenko 1966

Vernot et al. 1977













22,743 mg/m3

5,250 mg/m3

3,150 mg/m3

5,670 mg/m3

2,274 mg/m3

525 mg/m3

315 mg/m3

567 mg/m3

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

Revised IDLH: 300 mg/m3 [Unchanged]

Basis for revised IDLH: No inhalation toxicity data are available on which to base an IDLH for p-nitroaniline. Therefore, based on acute oral toxicity data in animals [Matrka et al. 1978; Moskalenko 1966; Vernot et al. 1977], the original IDLH for p-nitroaniline (300 mg/m3) is not being revised at this time.


1. AIHA [1955]. Aniline. In: Hygienic guide series. Am Ind Hyg Assoc Q 16:331-332.

2 Back KC, Thomas AA, MacEwen JD [1972]. Reclassification of materials listed as transportation health hazards. Wright-Patterson Air Force Base, OH: 6570th Aerospace Medical Research Laboratory, Report No. TSA-20-72-3, pp. A-298 to A-299.

3. Matrka M, Rambousek V, Zverina Z [1978]. Toxicity of p-substituted derivatives of aniline in experimental rats. Ceskoslovenska Hygiena (Czechoslovak Hygiene) 23:168-172 (in Czechoslovakian).

4. Moskalenko EG [1966]. Toxicological characteristics of nitroanilines. Vop Komm Gig 6:89-94 (in Russian).

5. Vernot EH, MacEwen JD, Haun CC, Kinkead FR [1977]. Acute toxicity and skin corrosion data for some organic and inorganic compounds and aqueous solutions. Toxicol Appl Pharmacol 42:417-423.

6. von Oettingen WF [1941]. The aromatic amino and nitro compounds, their toxicity and potential dangers. Public Health Bulletin 271:34.

Page last reviewed: December 4, 2014