2-Aminopyridine

CAS number . . . . . . . . . . . 504-29-0
NIOSH REL. . . . . . . . . . . . 0.5 ppm (2 mg/m3) TWA
Current OSHA PEL . . . . . . . . 0.5 ppm (2 mg/m3) TWA
1989 OSHA PEL. . . . . . . . . . Same as current PEL
1993-1994 ACGIH TLV. . . . . . . 0.5 ppm (1.9 mg/m3) TWA
Description of substance . . . . White powder, leaflets, or crystals with a
                                 characteristic odor.
LEL. . . . . . . . . . . . . . . Unknown
Original (SCP) IDLH. . . . . . . 5 ppm
Basis for original (SCP) IDLH. . Very little quantitative data are available
                                 on which to base an IDLH for 2-aminopyridine.
                                 The chosen IDLH is based on the statement
                                 by ACGIH [1971] that a 5-hour exposure to
                                 about 5 ppm produced headache, increased
                                 blood pressure, and nausea in a worker
                                 [Watrous and Schulz 1950].
Short-term exposure guidelines . None developed

ACUTE TOXICITY DATA

Lethal dose data:

                                                                              
                                    LD50     LDLo                      Derived
Species     Reference       Route (mg/kg)  (mg/kg)    Adjusted LD       Value
______________________________________________________________________________
Rat      Marhold 1986       oral    200     -----       385 ppm         39 ppm
Mouse    Verschueren 1983   oral     50     -----        90 ppm          9 ppm

         
Human data . . . . . . . . . . . A 5-hour exposure to approximately 5 ppm
                                 caused severe headache, increased blood
                                 pressure, flushing of the extremities, and
                                 nausea [Watrous and Schulz 1950]

Revised IDLH: 5 ppm [Unchanged]
Basis for revised IDLH: Based on acute inhalation toxicity data in humans [Watrous and Schulz 1950], the original IDLH for 2-aminopyridine (5 ppm) is not being revised at this time. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations above 5 ppm.

REFERENCES:

1. ACGIH [1971]. 2-Aminopyridine. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 11.
2. Marhold J [1986]. Prehled Prumyslove Toxikologie, Organicke Latky. Prague, Czechoslovakia: Avicenum, p. 838 (in Czechoslovakian).
3. Verschueren K [1983]. Handbook of environmental data of organic chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold, Co., p. 192.
4. Watrous RM, Schulz HN [1950]. Cyclohexylamine, p-chlornitrobenzene, 2-aminopyridine: toxic effects in industrial use. Ind Med Surg 19(7):317-320.