Substance profile
4,4'-bi-o-toluidine
4,4'-bi-o-toluidine is colorless; in technical grades also brownish flakes.
01 · Identification
What 4,4'-bi-o-toluidine is
4,4'-bi-o-toluidine is colorless; in technical grades also brownish flakes. Its molecular formula is C14H16N2 and its molecular weight is 212.29 g/mol. It boils at 300 °C, melts at 129 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
02 · Identifiers
4,4'-bi-o-toluidine identifiers and molecular data
4,4'-bi-o-toluidine CAS number and EC number
4,4'-bi-o-toluidine molecular formula and molecular weight
03 · GHS classification
4,4'-bi-o-toluidine hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
4,4'-bi-o-toluidine pictograms and signal word
4,4'-bi-o-toluidine hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Acute toxicity - oral GHS chapter 3.1 | Category 4 | H302 | GHS07 |
| Carcinogenicity GHS chapter 3.6 | Category 1A or 1B | H350 | GHS08 |
| Hazardous to the aquatic environment - chronic GHS chapter 4.1 | Category 2 | H411 | GHS09 |
Where two values are shown with “or”, the hazard statement is shared by more than one category or by more than one class, and the code alone does not say which. H272, for example, belongs to oxidising liquids and to oxidising solids — the physical state decides. The binding answer for a specific entry is in the CLP Annex VI table itself.
4,4'-bi-o-toluidine hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H350 | May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H302 | Harmful if swallowed. |
| H411 | Toxic to aquatic life with long lasting effects. |
This page lists only the codes assigned to 4,4'-bi-o-toluidine. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
Safety Data Sheet
Getting an SDS for 4,4'-bi-o-toluidine
A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of 4,4'-bi-o-toluidine issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.
04 · Precautionary statements
4,4'-bi-o-toluidine precautionary statements
CLP Annex VI assigns 11 precautionary statements to 4,4'-bi-o-toluidine. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.
Prevention
What to do before and during handling so the hazard never happens.
Response
What to do once exposure, spillage or fire has already happened.
Disposal
What has to happen to the contents and the empty container.
Reading the notation. … is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.
05 · Names in the regulation
4,4'-bi-o-toluidine name in 23 EU languages
CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.
| Language | Name in CLP Annex VI Part 3 |
|---|---|
| Bulgarian български | 4,4′-би- o -толуидин |
| Spanish español | 4,4'-Bi- o -toluidina |
| Czech čeština | 4,4'-bi- o -toluidin |
| Danish dansk | 4,4'-bis- o -toluidin |
| German Deutsch | 4,4'-Bi- o -toluidin 3,3'-Dimethylbenzidino-Tolidin |
| Estonian eesti | 4,4'-bi- o -toluidiin |
| Greek ελληνικά | 4,4′-δι- o -τολουιδίνη |
| English English | 4,4'-bi- o -toluidine |
| French français | 4,4'-bi- o -toluidine |
| Croatian hrvatski | 4,4'-bi- o -toluidin |
| Italian italiano | 4,4'-bi- o -toluidina |
| Latvian latviešu | 4,4'-bi- o -toluidīns |
| Lithuanian lietuvių | 4,4'-bi- o -toluidinas |
| Hungarian magyar | 4,4'-bi- o -toluidin |
| Maltese Malti | 4,4'-bi- o -toluidina |
| Dutch Nederlands | 4,4'-bi- o -toluïdine |
| Polish polski | 4,4'-bi- o -toluidyna 3,3'-dimetylobenzydynao -tolidyna |
| Portuguese português | 4,4'-bi- o -toluidina |
| Romanian română | 4,4'-bis- o -toluidină |
| Slovak slovenčina | 3,3'-dimetylbenzidín |
| Slovenian slovenščina | 4,4'-bi- o -toluidin |
| Finnish suomi | 4,4'-bi- o -toluidiini |
| Swedish svenska | 4,4'-bi- o -toluidin |
All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.
06 · Label elements
4,4'-bi-o-toluidine GHS label elements
Everything CLP Annex VI fixes for 4,4'-bi-o-toluidine, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
4,4'-bi-o-toluidine
- May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Harmful if swallowed.
- Toxic to aquatic life with long lasting effects.
- Obtain special instructions before use.
- Do not eat, drink or smoke when using this product.
- Avoid release to the environment.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF exposed or concerned:
- Call a POISON CENTER/doctor/… if you feel unwell.
- Get medical advice/attention.
- Rinse mouth.
- Collect spillage.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open 4,4'-bi-o-toluidine in the GHS label constructor →
07 · Health hazards
4,4'-bi-o-toluidine health hazards and exposure limits
4,4'-bi-o-toluidine hazard summary
3,3'-Dimethylbenzidine is used as an intermediate in the production of dyes and pigments. Acute (short- term) exposure to high levels of 3,3'-dimethylbenzidine in humans may irritate the nose and throat. No information is available on the chronic (long-term), reproductive, developmental, or carcinogenic effects of 3,3'-dimethylbenzidine in humans. A study by the National Toxicology Program (NTP) reported that oral exposure to 3,3'-dimethylbenzidine dihydrochloride resulted in an increased incidence of tumors of the skin, liver, intestine, lung, and other organs. EPA has classified 3,3'-dimethylbenzidine as a Group B2, probable human carcinogen.
Source: EPA Hazardous Air Pollutants
4,4'-bi-o-toluidine carcinogenicity classification
This substance/agent has not undergone a complete evaluation under U.S. EPA's IRIS program for evidence of human carcinogenic potential.
Source: Hazardous Substances Data Bank (HSDB)
No data are available in humans. Sufficient evidence of carcinogenicity in animals. OVERALL EVALUATION: Group 2B: The agent is possibly carcinogenic to humans.
Source: Hazardous Substances Data Bank (HSDB)
An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.
4,4'-bi-o-toluidine occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| REL | 0.02 mg/m³ [60 minutes] | Occupational Safety and Health Administration (OSHA) |
| REL | Ca C 0.02 mg/m3 [60-minute] [skin] See Appendix ASee Appendix C | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | A potential occupational carcinogen. (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | NIOSH considers o-tolidine to be a potential occupational carcinogen. | Hazardous Substances Data Bank (HSDB) |
| IDLH | Ca [N.D.] | The National Institute for Occupational Safety and Health (NIOSH) |
These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.
08 · Physical and chemical properties
4,4'-bi-o-toluidine properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
4,4'-bi-o-toluidine boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 300 °C (572 °F) | HSDB | |
| 200 °C (392 °F) | at 760 mmHg | CAMEO |
4,4'-bi-o-toluidine melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 128.89 °C (264 °F) | HSDB |
4,4'-bi-o-toluidine density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.234 g/cm³ | HSDB | |
| 1 g/cm³ | CAMEO | ||
| 1.2 g/cm³ | ICSC |
4,4'-bi-o-toluidine solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Soluble in alcohol, ether, dilute acids | HSDB | |
| 0.1% | NIOSH | ||
| In water, 1,300 mg/L at 25 °C | at 25 °C | HSDB |
4,4'-bi-o-toluidine vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 0.000001 mmHg | OSHA |
4,4'-bi-o-toluidine flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 244 °C (471.2 °F) | ICSC | |
| 243.89 °C (471 °F) | OSHA | ||
| 137 °C (278.6 °F) | Haz-Map |
4,4'-bi-o-toluidine autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 526 °C (978.8 °F) | ICSC |
4,4'-bi-o-toluidine lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | Combustible Solid | NIOSH |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Handling and storage
4,4'-bi-o-toluidine storage and handling
4,4'-bi-o-toluidine safe storage
Separated from strong oxidants and food and feedstuffs. Well closed. Store in an area without drain or sewer access. Provision to contain effluent from fire extinguishing.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
4,4'-bi-o-toluidine storage conditions
Separated from strong oxidants and food and feedstuffs. Well closed. Store in an area without drain or sewer access. Provision to contain effluent from fire extinguishing.
Source: Hazardous Substances Data Bank (HSDB)
4,4'-bi-o-toluidine incompatible materials
Strong oxidizers.
Source: Hazardous Substances Data Bank (HSDB)
4,4'-bi-o-toluidine reactivity
3,3'-DIMETHYLBENZIDINE is sensitive to exposure to light. May be sensitive to prolonged exposure to air. A weak base that forms salts with hydrochloric acid or sulfuric acid. It can be acetylated. Incompatible with strong agents (NTP, 1992).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check 4,4'-bi-o-toluidine in the storage compatibility matrix →
10 · Questions
4,4'-bi-o-toluidine — frequently asked questions
What is the CAS number of 4,4'-bi-o-toluidine?
The CAS number of 4,4'-bi-o-toluidine is 119-93-7. Its EC number is 204-358-0.
What is the chemical formula of 4,4'-bi-o-toluidine?
The molecular formula of 4,4'-bi-o-toluidine is C14H16N2 and its molecular weight is 212.29 g/mol.
What does a 4,4'-bi-o-toluidine label have to show?
Under CLP Annex VI the label for 4,4'-bi-o-toluidine carries the pictograms Health hazard, Exclamation mark and Environment and the signal word is Danger.
Is 4,4'-bi-o-toluidine flammable?
CLP Annex VI assigns 4,4'-bi-o-toluidine no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it. The flash point reported for it is 244 °C (471.2 °F) (ICSC).
Is 4,4'-bi-o-toluidine a carcinogen?
Yes. CLP Annex VI classifies 4,4'-bi-o-toluidine as a category 1A or 1B carcinogen and assigns it H350: may cause cancer. IARC places it in Group 2B: possibly carcinogenic to humans.
What is the boiling point of 4,4'-bi-o-toluidine?
The boiling point reported for 4,4'-bi-o-toluidine is 300 °C (572 °F) (HSDB).
What is the melting point of 4,4'-bi-o-toluidine?
The melting point reported for 4,4'-bi-o-toluidine is 128.89 °C (264 °F) (HSDB).
How should 4,4'-bi-o-toluidine be stored?
Separated from strong oxidants and food and feedstuffs. Well closed. Store in an area without drain or sewer access. Provision to contain effluent from fire extinguishing. (Hazardous Substances Data Bank (HSDB))
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