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Chemical Sampling Information (CSI)
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General Description

Synonyms: 4,4'-Diamino-3,3'-dimethylbiphenyl; Diaminoditolyl; 3,3'-Dimethylbenzidine; 3,3'-Dimethyl-4,4'-diphenyldiamine; 3,3'-Tolidine

OSHA IMIS Code Number: T169

Chemical Abstracts Service (CAS) Registry Number: 119-93-7

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: DD1225000; 14667

NIOSH Pocket Guide to Chemical Hazards, o-Tolidine: Chemical description, physical properties, potentially hazardous incompatibilities, and more

Health Factors

Carcinogenic Classification:
International Agency for Research on Cancer (IARC): Group 2B, possibly carcinogenic to humans (3,3'-Dimethylbenzidine and 3,3'-dimethylbenzidine-based dyes) [479 KB PDF, 63 pages]

National Toxicology Program (NTP): Reasonably anticipated to be a human carcinogen (3,3'- Dimethylbenzidine and Dyes Metabolized to 3,3'-Dimethlybenzidine) [183 KB PDF, 3 pages]
Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):
  • sampling media: Polytetrafluoroethylene Filter 5 micron
    maximum volume: 500 Liters   
    maximum flow rate:
    2.0 L/min
    current analytical method: High Performance Liquid Chromatography; HPLC/UL51
    method reference: 1 (NIOSH 5013 [28 KB PDF, 5 pages])
    method classification: Partially Validated

Wipe Sampling Method:

  • sampling media: Glass Fiber Filter

Bulk Method:

  • Protect samples from heat and light. This method does not differentiate between different o-Toliding based dyes. For any dye analysis, a bulk sample of the dye must be sent to the Salt Lake Technical Center. Limit the amount of bulk submitted to one gram or one mL.

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