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

CAS number: 479–45–8

NIOSH REL: 1.5 mg/m3 TWA [skin]

Current OSHA PEL: 1.5 mg/m3 TWA [skin]

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 1.5 mg/m3 TWA

Description of substance: Colorless to yellow, odorless, crystalline solid.

LEL: . . Unknown

Original (SCP) IDLH*: No Evidence [*Note: “Effective” IDLH = 3,000 mg/m3 — see discussion below.]

Basis for original (SCP) IDLH: The available toxicological data contain no evidence that an acute exposure to a high concentration of tetryl would impede escape or cause any irreversible health effects within 30 minutes. For this draft technical standard, therefore, respirators have been assigned on the basis of the assigned protection factor afforded by each device up to 2,000 ´ the OSHA PEL of 1.5 mg/m3 (i.e., 3,000 mg/m3); only the “most protective” respirators are permitted for use in concentrations exceeding 3,000 mg/m3.

Short-term exposure guidelines: None developed


Lethal dose data:

Species Reference Route LD50




Adjusted LD Derived value
Dog Wells et al. 1920 s.c. ----- 5,000 35,000 mg/m3 3,500 mg/m3

Human data: Tetryl is highly irritating to the skin and mucous membranes and may cause severe upper respiratory tract irritation with coughing and epistaxis; heavy airborne exposures may also cause liver damage [Hardy and Maloof 1950]. No systemic poisoning was noted following chronic exposure to 1.5 mg/m3, other than some skin sensitization [Bergman 1952].

Revised IDLH: 750 mg/m3

Basis for revised IDLH: Based on acute subcutaneous toxicity data in animals [Wells et al. 1920], a value of about 3,500 mg/m3 would have been appropriate. However, the revised IDLH for tetryl is 750 mg/m3 based on being 500 times the NIOSH REL and OSHA PEL of 1.5 mg/m3 (500 is an assigned protection factor for respirators and was used arbitrarily during the Standards Completion Program for deciding when the "most protective" respirators should be used for particulates).


1. Bergman BB [1952]. Tetryl toxicity: a summary of ten years experience. AMA Arch Ind Hyg Occup Med 5(1):10-20.

2. Hardy WL, Maloof CC [1950]. Evidence of systemic effect of tetryl. AMA Arch Ind Hyg Occup Med 1:545-555.

3. Wells HG, Lewis JH, Sansum WD, McClure WB, Lussky HO [1920]. Observations on the toxicity of tetranitromethylaniline (tetryl), tetranitroxylene (T.N.X.), tetranitraniline (T.N.A.), dinitrodichlorbenzene (parazol), and metanitraniline. J Ind Hyg 2:247-252.

Page last reviewed: December 4, 2014