Methyl acetylene-propadiene mixture (MAPP)

CAS number: 59355–75–8

NIOSH REL: 1,000 ppm (1,800 mg/m³) TWA,

1,250 ppm (2,250 mg/m³) STEL

Current OSHA PEL: 1,000 ppm (1,800 mg/m³) TWA

1989 OSHA PEL: 1,000 ppm (1,800 mg/m³) TWA,

1,250 ppm (2,250 mg/m³) STEL

1993-1994 ACGIH TLV: 1,000 ppm (1,640 mg/m³) TWA,

1,250 ppm (2,050 mg/m³) STEL

Description of substance: Colorless gas with a strong, characteristic, foul odor.

LEL:. . 3.4% (10% LEL, 3,400 ppm)

Original (SCP) IDLH: 15,000 ppm

Basis for original (SCP) IDLH: Because the TLV for a methyl acetylene-propadiene mixture has been set by analogy to methyl acetylene [ACGIH 1971], the chosen IDLH is also set by analogy with methyl acetylene which has an IDLH of 15,000 ppm.

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA:

Animal or human data: None relevant for use in determining the revised IDLH.

Other data: The American Conference of Governmental Industrial Hygienists TLV for a methyl acetylene-propadiene mixture (MAPP) is based on an analogy to methyl acetylene [ACGIH 1991].

Revised IDLH: 3,400 ppm [LEL] Basis for revised IDLH: Since a methyl acetylene-propadiene mixture appears to have relatively low toxicity, and based on an analogy to methyl acetylene [ACGIH 1991], the revised IDLH is 3,400 ppm based strictly on safety considerations (i.e., being 10% of the lower explosive limit of 3.4%).

REFERENCES:

1. ACGIH [1971]. Methyl acetylene-propadiene mixture (MAPP). In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 154.

2. ACGIH [1991]. Methyl acetylene-propadiene mixture. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 930.