International Chemical Safety Cards 3,3'-DICHLOROBENZIDINE ICSC: 0481 3,3'-Dichlorobiphenyl-4,4'-ylenediamine 4,4'-Diamino-3,3'-dichlorobiphenyl C6H3ClNH2C6ClNH2/C12H10Cl2N2 Molecular mass: 253.1 ICSC #    0481 CAS #     91-94-1 RTECS # DD0525000 EC #         612-068-00-4 April 20, 1994 Peer reviewed TYPES OF HAZARD/ EXPOSURE ACUTE HAZARDS/ SYMPTOMS PREVENTION FIRST AID/ FIRE FIGHTING FIRE Combustible. Gives off irritating or toxic fumes (or gases) in a fire. NO open flames. Powder, water spray, foam, carbon dioxide. EXPLOSION EXPOSURE PREVENT DISPERSION OF DUST! PREVENT GENERATION OF MISTS! AVOID ALL CONTACT! IN ALL CASES CONSULT A DOCTOR!  •INHALATION Cough. Sore throat. Avoid inhalation of fine dust and mist. Local exhaust or breathing protection. Fresh air, rest. Refer for medical attention.  •SKIN MAY BE ABSORBED! Protective gloves. Protective clothing. Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention.  •EYES Face shield or eye protection in combination with breathing protection if powder. First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.  •INGESTION Do not eat, drink, or smoke during work. Wash hands before eating. Rinse mouth. Refer for medical attention. SPILLAGE DISPOSAL STORAGE PACKAGING & LABELLING Sweep spilled substance into sealable containers; if appropriate, moisten first to prevent dusting. Carefully collect remainder, then remove to safe place. Do NOT let this chemical enter the environment (extra personal protection: complete protective clothing including self-contained breathing apparatus). Separated from food and feedstuffs. Well closed. Do not transport with food and feedstuffs. Note: E T symbol R: 45-21-43 S: 53-45 SEE IMPORTANT INFORMATION ON BACK ICSC: 0481 Prepared in the context of cooperation between the International Programme on Chemical Safety & the Commission of the European Communities (C) IPCS CEC 1994. No modifications to the International version have been made except to add the OSHA PELs, NIOSH RELs and NIOSH IDLH values.

International Chemical Safety Cards 3,3'-DICHLOROBENZIDINE ICSC: 0481 I M P O R T A N T D A T A PHYSICAL STATE; APPEARANCE: GREY TO PURPLE CRYSTALS. PHYSICAL DANGERS: CHEMICAL DANGERS: The substance decomposes on heating producing toxic and corrosive fumes including nitrogen oxides and hydrogen chloride. OCCUPATIONAL EXPOSURE LIMITS: TLV: ppm; mg/m3 A2 (skin) (ACGIH 1993-1994). OSHA PEL: 1910.1007 See Appendix B NIOSH REL: Ca See Appendix A NIOSH IDLH: Potential occupational carcinogen No data ROUTES OF EXPOSURE: The substance can be absorbed into the body by inhalation of its aerosol, through the skin and by ingestion. INHALATION RISK: Evaporation at 20°C is negligible; a harmful concentration of airborne particles can, however, be reached quickly when dispersed, especially if powdered. EFFECTS OF SHORT-TERM EXPOSURE: The substance irritates the respiratory tract. EFFECTS OF LONG-TERM OR REPEATED EXPOSURE: Repeated or prolonged contact with skin may cause dermatitis. The substance may have effects on the liver. This substance is probably carcinogenic to humans. PHYSICAL PROPERTIES Boiling point: 368°C Melting point: 132-133°C Solubility in water: none Auto-ignition temperature: 350°C ENVIRONMENTAL DATA The substance is toxic to aquatic organisms. N O T E S The substance is combustible but no flash point is available in literature. Curithane C126 is a trade name. Transport Emergency Card: TEC (R)-61G12b ADDITIONAL INFORMATION ICSC: 0481 3,3'-DICHLOROBENZIDINE (C) IPCS, CEC, 1994

IMPORTANT LEGAL NOTICE: Neither NIOSH, the CEC or the IPCS nor any person acting on behalf of NIOSH, the CEC or the IPCS is responsible for the use which might be made of this information. This card contains the collective views of the IPCS Peer Review Committee and may not reflect in all cases all the detailed requirements included in national legislation on the subject. The user should verify compliance of the cards with the relevant legislation in the country of use. The only modifications made to produce the U.S. version is inclusion of the OSHA PELs, NIOSH RELs and NIOSH IDLH values.