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

CAS number: 17702–41–9

NIOSH REL: 0.3 mg/m3 (0.05 ppm) TWA, 0.9 mg/m3 (0.15 ppm) STEL [skin]

Current OSHA PEL: 0.3 mg/m3 (0.05 ppm) TWA [skin]

1989 OSHA PEL: 0.3 mg/m3 (0.05 ppm) TWA, 0.9 mg/m3 (0.15 ppm) STEL [skin]

1993-1994 ACGIH TLV: 0.25 mg/m3 (0.05 ppm) TWA,

0.75 mg/m3 (0.15 ppm) STEL [skin]

Description of Substance: Colorless to white crystalline solid with an intense, bitter, chocolate­like odor.

LEL:. . Unknown

Original (SCP) IDLH: 100 mg/m3

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by ILO [1971] that the 4­hour LC50 was 122 to 230 mg/m3 for small animals.

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50 LCLo Time Adjusted 0.5-hrLC (CF) Derivedvalue


Schechter 1958Schechter 1958

Svirbely 1954

276 mg/m372 mg/m3

144 mg/m3



4 hr4 hr

4 hr

552 mg/m3 (2.0)144 mg/m3 (2.0)

288 mg/m3 (2.0)

55 mg/m314 mg/m3

29 mg/m3


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



1. ILO [1971]. Boron hydrides. In: Encyclopaedia of occupational health and safety. 2nd ed. Vol. I (A­K). Geneva, Switzerland: International Labour Office, p. 206.

2. Schechter WH [1958]. Toxicity of high energy fuels. AMA Arch Ind Health 17:362­366.

3. Svirbely JL [1954]. Acute toxicity studies of decaborane and pentaborane by inhalation. AMA Arch Ind Hyg Occup Med 10:298­304.

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