This chemical has two CAS numbers listed, one for benzoic acid (CASRN: 65-85-0) and the other for the sodium salt of benzoic acid, also known as sodium benzoate (CASRN: 532-32-1). As the acute toxicity of sodium benzoate is similar to that of benzoic acid, as are the symptoms (Smyth & Carpenter, 1948; Deuel et al., 1954; Bayer AG, 1977), both chemicals were investigated with the same methodologies to determine the most preferable TEELs.
A review of available exposure limits identified the following: TLV-TWA for benzoic acid and TLV-TWA for sodium benzoate, as inhalable fractions. Toxicity data for benzoic acid includes the following: human (male) LDLo and rat oral LD50 doses. For sodium benzoate, dog oral LD50 and rat oral LD50 doses are available. Each was evaluated using the guidelines for calculating equivalent values in the TEEL Handbook. The dog oral LD50 was determined to be the preferable starting point for TEEL-3, based on the dose type, species, and source age/credibility. TEEL-2 and TEEL-1 values were derived from this TEEL-3, according to Table 3.5.
• TEEL-1 = TEEL-2/11
• TEEL-2 = TEEL-3/6
• TEEL-3 = Dog oral LD50 (2000 mg/kg)
This review generated TEEL values that were inconsistent with those published in Rev. 29A. TEEL-3 is slightly less conservative, while TEEL-2 and TEEL-1 are more conservative. In Rev. 29A the TEEL-3 basis was a rat oral LD50 while the TEEL-2 basis was a rat oral TDLo; these specific sources were not identified during current research.