Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 1335–87–1
NIOSH REL: 0.2 mg/m3 TWA [skin]
Current OSHA PEL: 0.2 mg/m3 TWA [skin]
1989 OSHA PEL: Same as current PEL
1993-1994 ACGIH TLV: 0.2 mg/m3 TWA [skin]
Description of Substance: White to light-yellow solid with an aromatic odor.
LEL:. . Noncombustible Solid
Original (SCP) IDLH: 2 mg/m3
Basis for original (SCP) IDLH: Although AIHA  stated that “IDLHs for the chloronaphthalenes are probably unattainable,” an IDLH of 2 mg/m3 for hexachloronaphthalene has been chosen for this draft technical standard. The chosen IDLH is based on the industrial exposure cited by ACGIH  in which fatal cases of hepatic injury occurred in a plant where air concentrations of mixed pentachloronaphthalenes and hexachloronaphthalenes ranged from 1 to 2 mg/m3 [Elkins 1959].
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA
Animal data: Repeated exposure of rats to 8.9 mg/m3 of a mixture of hexachloronaphthalene and pentachloronaphthalene for up to 4.5 months produced jaundice and was fatal; minor liver injury still occurred at 1.16 mg/m3 [Drinker et al. 1937]. Hexachloronaphthalene has been shown to be more toxic than pentachloronaphthalene in ingestion studies with calves [Bell 1958]. Total doses of hexachloronaphthalene ranging from 5 to 23 mg/kg were given orally in mineral oil over 10 days and lacrimation, salivation, nasal discharge, depression, and anorexia occurred by the 5th day [Bell 1958].
Human data: It has been reported that fatal cases of hepatic injury have occurred from chronic exposures in a plant where air concentrations of mixed pentachloronaphthalenes and hexachloronaphthalenes ranged from 1 to 2 mg/m3 [Elkins 1959].
|Revised IDLH: 2 mg/m3 [Unchanged]
Basis for revised IDLH: Based on chronic inhalation toxicity data in humans [Elkins 1959] and animals [Bell 1958, Drinker 1937], the original IDLH for hexachloronaphthalene (2 mg/m3) is not being revised at this time.
1. ACGIH . Hexachloronaphthalene. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 125.
2. AIHA . Chloronaphthalenes. In: Hygienic guide series. Am Ind Hyg Assoc J 27:89.
3. Bell WB . The relative toxicity of the chlorinated naphthalenes in experimentally produced bovine hyperkeratosis (x-disease). Vet Med 48:135-140.
4. Drinker CK, Warren MF, Bennett GA . The problem of possible systemic effects from certain chlorinated hydrocarbons. J Ind Hyg Toxicol 19(7):283-299.
5. Elkins HB . The chemistry of industrial toxicology. 2nd ed. New York, NY: John B. Wiley & Sons, Inc., pp. 151-152.