Benzoyl peroxide

CAS number . . . . . . . . . . . 94-36-0
NIOSH REL. . . . . . . . . . . . 5 mg/m3 TWA
Current OSHA PEL . . . . . . . . 5 mg/m3 TWA
1989 OSHA PEL. . . . . . . . . . Same as current PEL
1993-1994 ACGIH TLV. . . . . . . 5 mg/m3 TWA
Description of Substance . . . . Colorless to white crystals or a granular
                                 powder with a faint, benzaldehyde-like odor.
LEL. . . . . . . . . . . . . . . Unknown
Original (SCP) IDLH. . . . . . . 7,000 mg/m3
Basis for original (SCP) IDLH. . The chosen IDLH is based on the estimated
                                 mouse 4-hour LC50 of 700 ppm (7,000 mg/m3)
                                 for benzoyl peroxide cited by ACGIH [1971].
                                 However, this concentration is not an actual
                                 LC50 value for benzoyl peroxide; it was
                                 estimated by ACGIH [1971] by analogy from
                                 data concerning LC50 values for other related
                                 organic peroxides [Floyd and Stokinger 1958].
Short-term exposure guidelines . None developed

ACUTE TOXICITY DATA

Lethal concentration data:

                                                    Adjusted               
                                                     0.5-hr           Derived
Species  Reference     LC50       LCLo   Time        LC (CF)         Value PPM
______________________________________________________________________________
Mouse   Floyd and   7,000 mg/m3   -----  4 hr  14,000 mg/m3 (2.0)  1,400 mg/m3
        Stokinger 
        1958

Lethal dose data:

                                                                             
                                  LD50     LDLo                       Derived
Species     Reference    Route   (mg/kg)  (mg/kg)    Adjusted LD       Value
______________________________________________________________________________
Mouse    ARCO 1982       oral     7,710    -----    53,970 mg/m3   5,397 mg/m3

Human data . . . . . . . . . . . Concentrations of 12 mg/m3 and higher have
                                 resulted in pronounced irritation of the nose
                                 and throat [Moskowitz and Grabois 1950].

Revised IDLH: 1,500 mg/m3
Basis for revised IDLH: The revised IDLH for benzoyl peroxide is 1,500 mg/m3 based on acute inhalation toxicity data in animals [Floyd and Stokinger 1958].

REFERENCES:

1. ACGIH [1971]. Acetaldehyde. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 23-24.
2. ARCO [1982]. Toxicology report. 70% aqueous tertiary butyl hydroperoxide: acute toxicity evaluation. Newtown Square, PA: Arco Chemical Company, June 1982.
3. Floyd EP, Stokinger HE [1958]. Toxicity studies of certain organic peroxides and hydroperoxides. Am Ind Hyg Assoc J 19:205-212.
4. Moskowitz S, Grabois B [1950]. Unpublished report sent to ACGIH. Albany, NY: New York State Department of Labor, Division of Industrial Hygiene (November 1950). [From ACGIH [1991]. Benzoyl peroxide. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 123-124.]