English Safety Data Sheet Database 中文版 MSDS

o-Dianisidine dihydrochloride

CAS No. 20325-40-0 | PubChem CID 62311
Section 1. Identification
Chemical Nameo-Dianisidine dihydrochloride CAS No.20325-40-0
Synonyms2-dianisidinedihydrochloride; 3,3'-dimethoxybenzidinedihydrochloride Chinese Name3,3'-二甲氧基联苯胺二盐酸盐
Molecular FormulaC14H16N2O2 Molecular Weight317.214
UN No.3261 Data SourcePubChem (NIH/NLM)
GHS Hazard Classification
Signal Word DANGER
Pictograms GHS05 · Corrosive GHS07 · Irritant GHS08 · Health Hazard
Hazard Statements H302H314H318H350
Precautionary Statements P203P260P264P264+P265P270P280P301+P317P301+P330+P331P302+P361+P354P304+P340P305+P354+P338P316P317P318P321P330P363P405P501

Section 2. Hazards Identification

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

H314 (15.4%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H318 (15.4%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H350 (98.1%): May cause cancer [Danger Carcinogenicity]

P203, P260, P264, P264+P265, P270, P280, P301+P317, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P318, P321, P330, P363, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 52 reports by companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

Not Classified

Section 4. First-Aid Measures

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital.

OTHER: Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, its chemical, physical and toxicity properties, the exposure level, length of exposure, and the route of exposure. (NTP, 1992)

Section 5. Fire-Fighting Measures

Fires involving this compound should be controlled with a dry chemical, carbon dioxide or Halon extinguisher. (NTP, 1992)

Section 7. Handling and Storage

SMALL SPILLS AND LEAKAGE: If you spill this chemical, you should dampen the solid spill material with water, then transfer the dampened material to a suitable container. Use absorbent paper dampened with water to pick up any remaining material. Seal your contaminated clothing and the absorbent paper in a vapor-tight plastic bag for eventual disposal. Wash all contaminated surfaces with a strong soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

STORAGE PRECAUTIONS: You should keep this material in a tightly-closed container under an inert atmosphere, and store it at refrigerated temperatures. (NTP, 1992)

Section 8. Exposure Controls / Personal Protection

5.8 [mg/m3]

63 [mg/m3]

380 [mg/m3]

MINIMUM PROTECTIVE CLOTHING: If Tyvek-type disposable protective clothing is not worn during handling of this chemical, wear disposable Tyvek-type sleeves taped to your gloves.

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with a combination filter cartridge, i.e. organic vapor/acid gas/HEPA (specific for organic vapors, HCl, acid gas, SO2 and a high efficiency particulate filter). (NTP, 1992)

Section 9. Physical and Chemical Properties

3,3'-dimethoxybenzidine dihydrochloride is an off-white powder. (NTP, 1992)

Wet Solid; CBI

514 °F (NTP, 1992)

10 to 50 mg/mL at 68 °F (NTP, 1992)

0.0000000088 [mm Hg] @25 °C

Section 10. Stability and Reactivity

Water soluble.

Salts, Acidic

3,3'-DIMETHOXYBENZIDINE DIHYDROCHLORIDE is an ether substituted acidic organic salt. Reacts weakly as a acid to neutralize bases. May react with strong oxidizing agents or strong reducing agents.

Section 11. Toxicological Information

3,3'-Dimethoxybenzidine Dihydrochloride

TR-372: Toxicology and Carcinogenesis Studies of 3,3'-Dimethoxybenzidine Dihydrochloride (CASRN 20325-40-0) in F344/N Rats (Drinking Water Studies) (1990 )

06/27/89

Clear Evidence

Chemical Not Tested in Species/Sex

Under the conditions of these 21-month drinking water studies, there was clear evidence of carcinogenic activity of 3,3'-dimethoxybenzidine dihydrochloride for male F344/N rats, as indicated by benign and malignant neoplasms of the skin, Zymbal gland, preputial gland, oral cavity, intestine, liver, and mesothelium. Increased incidences of astrocytomas of the brain may have been related to chemical administration. There was clear evidence of carcinogenic activity of 3,3'-dimethoxybenzidine dihydrochloride for female F344/N rats, as indicated by benign and malignant neoplasms of the Zymbal gland, clitoral gland, and mammary gland. Increases in neoplasms of the skin, oral cavity, large intestine, liver, and uterus/cervix were also considered to be related to chemical administration of 3,3'-dimethoxybenzidine dihydrochloride.

Source: PubChem CID 62311 (NIH/NLM, public domain). Retrieved from PubChem, a public-domain chemistry database maintained by the U.S. National Library of Medicine. Last updated: 2026-08-02 09:38:06.
Disclaimer: This information is compiled for reference only and does not replace the manufacturer's official Safety Data Sheet. Always consult the supplier's SDS before handling any chemical.