Isopropyl ether

CAS number: 108–20–3

NIOSH REL: 500 ppm (2,100 mg/m³) TWA

Current OSHA PEL: 500 ppm (2,100 mg/m³) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 250 ppm (1,040 mg/m³) TWA, 310 ppm (1,300 mg/m³) STEL

Description of substance: Colorless liquid with a sharp, sweet, ether-like odor.

LEL: . . 1.4% (10% LEL, 1,400 ppm)

Original (SCP) IDLH: 10,000 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the UCC [1968] report that breathing the vapors in a state approaching saturation in room air killed all rats in a 10-minute exposure. [Note: Based on a vapor pressure of 119 mmHg [Patty 1963], the saturated concentration of isopropyl ether in air at 20°C is about 157,000 ppm.] Breathing 8,000 ppm was not fatal after a 4-hour exposure, but 16,000 ppm killed 6 of 6 animals exposed for the same period of time [UCC 1968].

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA:

Lethal concentration data:

Species	Reference	LC50 (ppm)	LCLo (ppm)	Time	Adjusted 0.5-hr LC (CF)	Derived value
Rat	Pavlova et al. 1963	38,138	-----	?	?	?
Rabbit	Pavlova et al. 1963	30,840	-----	?	?	?
Rabbit	Pavlova et al. 1963	28,486	-----	?	?	?
Rat	UCC 1968	LC100: 157,000	-----	10 min	105,190 ppm (0.67)	10,519 ppm
Mammal	UCC 1968	LC100: 16,000	-----	4 hr	32,000 ppm (2.0)	3,200 ppm

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
Rabbit	Machle et al. 1939	oral	-----	5,000-6,500	8,235-10,706 ppm	824-1,071 ppm
Rat	UCC 1968	oral	8,470	-----	13,951 ppm	1,395 ppm

Other animal data: It has been reported that animals survived a 4-hour exposure to 8,000 ppm [UCC 1968].

Human data: Volunteers exposed to 800 ppm for 5 minutes reported irritation of the eyes and nose [Silverman et al. 1946].

Revised IDLH: 1,400 ppm [LEL] Basis for revised IDLH: Based on health considerations and acute inhalation toxicity data in animals [UCC 1968], a value of about 3,200 ppm would have been appropriate for isopropyl ether. However, the revised IDLH for isopropyl ether is 1,400 ppm based strictly on safety considerations (i.e., being 10% of the lower explosive limit of 1.4%).

REFERENCES:

1. Machle W, Scott EW, Treon J [1939]. The physiological response to isopropyl ether and to a mixture of isopropyl ether and gasoline. J Ind Hyg Toxicol 21:72-96.

2. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1662.

3. Pavlova LP, Lagunova VV, Imanov RM [1963]. Determination of the maximal permissible concentration of diisopropyl ether in the air of working zone. Gig Tr Prof Zabol 19(10):55-57 (in Russian).

4. Silverman L, Schulte HF, First MW [1946]. Further studies on sensory response to certain industrial solvent vapors. J Ind Hyg Toxicol 28:262-266.

5. UCC [1968]. Toxicology studies: isopropyl ether. New York, NY: Union Carbide Corporation.