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n-Propyl alcohol

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

CAS number: 71-23-8

NIOSH REL: 200 ppm (500 mg/m3) TWA, 250 ppm (625 mg/m3) STEL [skin]

Current OSHA PEL: 200 ppm (500 mg/m3) TWA

1989 OSHA PEL: 200 ppm (500 mg/m3) TWA, 250 ppm (625 mg/m3) STEL

1993-1994 ACGIH TLV: 200 ppm (492 mg/m3) TWA, 250 ppm (614 mg/m3) STEL [skin]

Description of substance: Colorless liquid with a mild, alcohol-like odor.

LEL: . . 2.2% (10% LEL, 2,200 ppm)

Original (SCP) IDLH: 4,000 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Patty [1963] that 2 of 6 rats died following a 4-hour exposure to 4,000 ppm [Smyth et al. 1954]. In addition, Patty [1963] reported that deep narcosis was produced in 2 mice exposed to 4,100 ppm for 4 hours [Starrek 1938].

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50(ppm) LCLo(ppm) Time Adjusted 0.5-hrLC (CF) Derived value
Rat Smyth et al. 1954 LC33: 4,000 —– 4 hr 8,000 ppm (2.0) 800 ppm

Lethal dose data:

Species Reference Route LD50(mg/kg) LDLo(mg/kg) Adjusted LD Derived value
Rabbit Munch & Schwartze 1925 oral 2,800 —– 7,840 ppm 784 ppm
Mouse Savini 1968 oral 6,800 —– 19,040 ppm 1,904 ppm
Rat Smyth et al. 1954 oral 1,870 —– 5,236 ppm 524 ppm

Other animal data: RD50 (mouse), 12,704 ppm [Alarie 1981]. It has been reported that deep narcosis was produced in 2 mice exposed to 4,100 ppm for 4 hours [Starrek 1938].

Human data: Mild irritation of the eyes, nose, and throat have been reported at 400 ppm [Nelson et al. 1943]. It has been reported that 5,700 mg/kg is the lethal oral dose [Durwald and Degen 1956]. [Note: An oral dose of 5,700 mg/kg is equivalent to a 70-kg worker being exposed to about 94,000 ppm for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]

Revised IDLH: 800 ppmBasis for revised IDLH: The revised IDLH for n-propyl alcohol is 800 ppm based on acute inhalation toxicity data in humans [Nelson et al. 1943] and animals [Smyth et al. 1954]. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations above 400 ppm.


1. Alarie Y [1981]. Dose-response analysis in animal studies: prediction of human responses. Environ Health Perspect 42:9-13.

2. Durwald W, Degen W [1956]. Eine todliche vergiftung mit n-propyl alkohol. Arch Toxikol 16:85 (in German). [From ACGIH [1991]. n-Propyl alcohol. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 1301-1302.]

3. Munch JC, Schwartze EW [1925]. Narcotic and toxic potency of aliphatic alcohols upon rabbits. J Lab Clin Med 10:985-996.

4. Nelson KW, Ege JF, Ross M, Woodman LE, Silverman L [1943]. Sensory response to certain industrial solvent vapors. J Ind Hyg Toxicol 25(7):282-285.

5. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., pp. 1434-1435.

6. Savini EC [1968]. Estimation of the LD50 in mol/kg. Proc Eur Soc St Drug Tox 9:276-278.

7. Smyth HF Jr, Carpenter CP, Weil CS, Pozzani UC [1954]. Range-finding toxicity data: list V. AMA Arch Ind Hyg Occup Med 10:61-68.

8. Starrek E [1938]. The effect of some alcohols, glycols, and esters. Doctoral dissertation (translated). Wurzburg, Germany: Julius Maximillian University.