May 1994

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

Sulfuric acid

CAS number: 7664–93–9

NIOSH REL: 1 mg/m³ TWA

Current OSHA PEL: 1 mg/m³ TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 1 mg/m³ TWA, 3 mg/m³ STEL

Description of substance: Colorless to dark-brown, oily, odorless liquid.

LEL: . . Noncombustible Liquid

Original (SCP) IDLH: 80 mg/m³

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by ACGIH [1971] that guinea pigs died after 2.75 hours of exposure at 87 mg/m³ [Treon et al. 1950].

Existing short-term exposure guidelines: National Research Council [NRC 1984] Emergency Exposure Guidance Levels (EEGLs):

10-minute EEGL: 5 mg/m³

30-minute EEGL: 2 mg/m³

60-minute EEGL: 1 mg/m³

ACUTE TOXICITY DATA:

Lethal concentration data:

Species	Reference	LC₅₀	LC_Lo	Time	Adjusted 0.5-hr LC (CF)	Derived value
G. pig	Amdur et al. 1952a	50 mg/m³	-----	8 hr	125 mg/m³ (2.5)	13 mg/m³
Rat	Izmerov et al. 1982	510 mg/m³	-----	2 hr	816 mg/m³ (1.6)	82 mg/m³
Mouse	Izmerov et al. 1982	320 mg/m³	-----	2 hr	512 mg/m³ (1.6)	51 mg/m³
G. pig	Raule 1954	18 mg/m³	-----	?	?	?
G. pig	Treon et al. 1950	-----	87 mg/m³	2.75 hr	154 mg/m³ (1.77)	15 mg/m³

Lethal dose data:

Species	Reference	Route	LD₅₀ (mg/kg)	LD_Lo (mg/kg)	Adjusted LD	Derived value
Rat	Smyth et al. 1969	oral	2,140	-----	14,980 mg/m³	1,498 mg/m³

Human data: In exposures of 5 to 15 minutes, some volunteers found 5 mg/m³ to be very objectionable, while others found it less so [Amdur et al. 1952b]. The lethal oral dose has been reported to be 135 mg/kg [Arena 1970]. [Note: An oral dose of 135 mg/kg is equivalent to a worker being exposed to about 6,300 mg/m³ for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]

Revised IDLH: 15 mg/m³

Basis for revised IDLH: The revised IDLH for sulfuric acid is 15 mg/m³ based on acute inhalation toxicity data in humans [Amdur et al. 1952b] and animals [Amdur et al. 1952a; Treon et al. 1950]. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations above 5 mg/m³.

REFERENCES:

1. ACGIH [1971]. Sulfuric acid. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 239-240.

2. Amdur MO, Schulz RZ, Drinker P [1952a]. Toxicity of sulfuric acid mist to guinea pigs. AMA Arch Ind Hyg Occup Med 5:318-329.

3. Amdur MO, Silverman L, Drinker P [1952b]. Inhalation of sulfuric acid mist by human subjects. AMA Arch Ind Hyg Occup Med 6(4):305-313.

4. Arena JM [1970]. Poisoning, toxicology, symptoms, treatments. 2nd ed. Springfield, IL: C.C. Thomas, p. 73.

5. Izmerov NF, Sanotsky IV, Sidorov KK [1982]. Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 107.

6. NRC [1984]. Emergency and continuous exposure limits for selected airborne contaminants. Vol. 1. Washington, DC: National Academy Press, Committee on Toxicology, Board on Toxicology and Environmental Health Hazards, Commission on Life Sciences, National Research Council, pp. 107-112.

7. Raule A [1954]. Occupational diseases caused by sulfuric acid. Med Lav 45:590-599 (in Italian).

8. Smyth HF Jr, Carpenter CP, Weil CS, Pozzani UC, Striegel JA, Nycum JS [1969]. Range-finding toxicity data: list VII. Am Ind Hyg Assoc J 30(5):470-476.

9. Treon JF, Dutra FR, Cappel J, Sigmon H, Younker W [1950]. Toxicity of sulfuric acid mist. AMA Arch Ind Hyg Occup Med 2:716-734.