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




Time Adjusted 0.5-hr


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




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 ppm

Basis 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.

Page last reviewed: December 4, 2014