Substance profile
1,2-dihydroxybenzene
1,2-dihydroxybenzene is monoclinic tablets, prisms from toluene its aqueous solutions soon turn brown with a faint characteristic odor.
01 · Identification
What 1,2-dihydroxybenzene is
1,2-dihydroxybenzene is monoclinic tablets, prisms from toluene its aqueous solutions soon turn brown with a faint characteristic odor. Its molecular formula is C6H6O2 and its molecular weight is 110.11 g/mol. It boils at 246 °C, melts at 105 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
02 · Identifiers
1,2-dihydroxybenzene identifiers and molecular data
1,2-dihydroxybenzene CAS number and EC number
1,2-dihydroxybenzene molecular formula and molecular weight
Other names for 1,2-dihydroxybenzene
- pyrocatechol
03 · GHS classification
1,2-dihydroxybenzene hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
1,2-dihydroxybenzene pictograms and signal word
1,2-dihydroxybenzene hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Acute toxicity - oral GHS chapter 3.1 | Category 3 | H301 | GHS06 |
| Acute toxicity - dermal GHS chapter 3.1 | Category 3 | H311 | GHS06 |
| Skin corrosion/irritation GHS chapter 3.2 | Category 2 | H315 | GHS07 |
| Serious eye damage/eye irritation GHS chapter 3.3 | Category 2A | H319 | GHS07 |
| Germ cell mutagenicity GHS chapter 3.5 | Category 2 | H341 | GHS08 |
| Carcinogenicity GHS chapter 3.6 | Category 1A or 1B | H350 | GHS08 |
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.
1,2-dihydroxybenzene 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>. |
| H341 | Suspected of causing genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H311 | Toxic in contact with skin. |
| H301 | Toxic if swallowed. |
| H315 | Causes skin irritation. |
| H319 | Causes serious eye irritation. |
This page lists only the codes assigned to 1,2-dihydroxybenzene. 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 1,2-dihydroxybenzene
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 1,2-dihydroxybenzene 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
1,2-dihydroxybenzene precautionary statements
CLP Annex VI assigns 15 precautionary statements to 1,2-dihydroxybenzene. 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.
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
1,2-dihydroxybenzene 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 | 1,2-дихидроксибензен пирокатехол |
| Spanish español | 1,2-Dihidroxibenceno pirocatecol |
| Czech čeština | benzen-1,2-diol pyrokatechol |
| Danish dansk | 1,2-dihydroxybenzen pyrocatechol |
| German Deutsch | 1,2-Dihydroxybenzol Brenzcatechin |
| Estonian eesti | 1,2-dihüdroksübenseen pürokatehhool |
| Greek ελληνικά | 1,2-διυδροξυβενζόλιο πυροκατεχόλη |
| English English | 1,2-dihydroxybenzene pyrocatechol |
| French français | 1,2-dihydroxybenzène pyrocatéchol |
| Croatian hrvatski | 1,2-dihidroksibenzen pirokatehol |
| Italian italiano | 1,2-diidrossibenzene pirocatecolo |
| Latvian latviešu | 1,2-dihidroksibenzols pirokatehols |
| Lithuanian lietuvių | 1,2-dihidroksibenzenas pirokatecholis |
| Hungarian magyar | 1,2-dihidroxibenzol pirokatechin |
| Maltese Malti | 1,2-diidrossibenżen pirokatekol |
| Dutch Nederlands | 1,2-dihydroxybenzeen pyrocatechol |
| Polish polski | 1,2-dihydroksybenzen pirokatechol |
| Portuguese português | 1,2-di-hidroxibenzeno pirocatecol |
| Romanian română | 1,2-dihidroxibenzen pirocatecol |
| Slovak slovenčina | 1,2-dihydroxybenzén pyrokatechol |
| Slovenian slovenščina | 1,2-dihidroksibenzen pirokatehol |
| Finnish suomi | 1,2-dihydroksibentseeni pyrokatekoli |
| Swedish svenska | 1,2-dihydroxibensen pyrokatekol |
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
1,2-dihydroxybenzene GHS label elements
Everything CLP Annex VI fixes for 1,2-dihydroxybenzene, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
1,2-dihydroxybenzene
- May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Suspected of causing genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Toxic in contact with skin.
- Toxic if swallowed.
- Causes skin irritation.
- Causes serious eye irritation.
- Obtain special instructions before use.
- Wash … thoroughly after handling.
- Do not eat, drink or smoke when using this product.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF ON SKIN:
- IF IN EYES:
- IF exposed or concerned:
- Immediately call a POISON CENTER/doctor/…
- Get medical advice/attention.
- Rinse mouth.
- If skin irritation occurs:
- If eye irritation persists:
- Remove contact lenses, if present and easy to do. Continue rinsing.
- Wash with plenty of water/…
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open 1,2-dihydroxybenzene in the GHS label constructor →
07 · Health hazards
1,2-dihydroxybenzene health hazards and exposure limits
1,2-dihydroxybenzene hazard summary
Exposure to catechol may occur during its manufacture and use. Skin contact with catechol causes eczematous dermatitis in humans. In humans, absorption through the skin results in an illness resembling that induced by phenol, except convulsions are more pronounced. Large doses of catechol can cause depression of the central nervous system (CNS) and a prolonged rise of blood pressure in animals. Due to the lack of information regarding the duration of exposure in the above studies, it is not clear whether these health effects were observed following acute (short-term) or chronic (long-term) exposure. Tumors in the glandular stomach were observed in orally exposed rats. The International Agency for Research on Cancer (IARC) has classified catechol as a Group 2B, possible human carcinogen. EPA has not classified catechol with respect to potential carcinogenicity.
Source: EPA Hazardous Air Pollutants
1,2-dihydroxybenzene carcinogenicity classification
Evaluation: No epidemiological data relevant to the carcinogenicity of catechol were available. There is sufficient evidence in experimental animals for the carcinogenicity of catechol. OVERALL EVALUATION: Catechol is possibly carcinogenic to humans (Group 2B).
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.
1,2-dihydroxybenzene occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | none See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 5 ppm (20 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 5 ppm (20 mg/m3) [skin] | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 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
1,2-dihydroxybenzene 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.
1,2-dihydroxybenzene boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 245.56 °C (474 °F) | NIOSH | |
| 245.5 °C (473.9 °F) | ICSC |
1,2-dihydroxybenzene melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 105 °C (221 °F) | HSDB |
1,2-dihydroxybenzene density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.344 g/cm³ | HSDB | |
| 1.371 g/cm³ | HSDB | ||
| 1.34 g/cm³ | NIOSH |
1,2-dihydroxybenzene solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Soluble in chloroform, ether; very soluble in pyridine, aqueous alkalis | HSDB | |
| Very soluble in alcohol, ethyl ether, acetate | HSDB | ||
| In water, 4.61X10+5 mg/L at 25 °C | at 25 °C | HSDB |
1,2-dihydroxybenzene vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 0.03 mmHg | at 20 °C | HSDB |
| 10 mmHg | at 118.3 °C | HSDB | |
| 10 mmHg | at 117.78 °C | NIOSH |
1,2-dihydroxybenzene flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 126.67 °C (260 °F) | HSDB | |
| 127.2 °C (261 °F) | open cup | HSDB | |
| 127 °C (260.6 °F) | HSDB |
1,2-dihydroxybenzene autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 510 °C (950 °F) | HSDB |
1,2-dihydroxybenzene lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 1.4 % by volume | NIOSH | |
| Flammability lower limit (vapor in air): 1.97% | HSDB |
1,2-dihydroxybenzene upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | Not Applicable. Combustible solid (USCG, 1999) | CAMEO | |
| NA | OSHA |
1,2-dihydroxybenzene vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 3.79 (air = 1) | HSDB | |
| 3.8 (air = 1) | ICSC |
1,2-dihydroxybenzene odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | detection: 8.0 mg/L | HSDB |
1,2-dihydroxybenzene critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 526.85 °C (980.3 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
1,2-dihydroxybenzene fire and explosion behaviour
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
1,2-dihydroxybenzene fire potential
Combustible when exposed to heat or flame.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
1,2-dihydroxybenzene storage and handling
1,2-dihydroxybenzene safe storage
Well closed. Separated from oxidants and food and feedstuffs. Keep in the dark. Ventilation along the floor. Store in an area without drain or sewer access.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
1,2-dihydroxybenzene storage conditions
Separated from strong oxidants, food and feedstuffs. Keep in the dark. Ventilation along the floor.
Source: Hazardous Substances Data Bank (HSDB)
1,2-dihydroxybenzene incompatible materials
Can react vigorously with oxidizing materials
Source: Hazardous Substances Data Bank (HSDB)
1,2-dihydroxybenzene reactivity
POISONOUS GASES MAY BE PRODUCED WHEN HEATED. CATECHOL may form toxic fumes at high temperatures. (USCG, 1999). This compound can react with acid chlorides, acid anhydrides, bases and oxidizing agents. It reacts violently on contact with concentrated nitric acid. It acts as a reducing agent (NTP, 1992).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check 1,2-dihydroxybenzene in the storage compatibility matrix →
11 · Questions
1,2-dihydroxybenzene — frequently asked questions
What is the CAS number of 1,2-dihydroxybenzene?
The CAS number of 1,2-dihydroxybenzene is 120-80-9. Its EC number is 204-427-5.
What is the chemical formula of 1,2-dihydroxybenzene?
The molecular formula of 1,2-dihydroxybenzene is C6H6O2 and its molecular weight is 110.11 g/mol.
What does a 1,2-dihydroxybenzene label have to show?
Under CLP Annex VI the label for 1,2-dihydroxybenzene carries the pictograms Health hazard and Skull and crossbones and the signal word is Danger.
Is 1,2-dihydroxybenzene flammable?
CLP Annex VI assigns 1,2-dihydroxybenzene 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 126.67 °C (260 °F) (HSDB).
Is 1,2-dihydroxybenzene a carcinogen?
Yes. CLP Annex VI classifies 1,2-dihydroxybenzene 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 exposure limit for 1,2-dihydroxybenzene?
The US occupational exposure limit reported for 1,2-dihydroxybenzene is none See Appendix G (The National Institute for Occupational Safety and Health (NIOSH)). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.
What is the boiling point of 1,2-dihydroxybenzene?
The boiling point reported for 1,2-dihydroxybenzene is 245.56 °C (474 °F) (NIOSH).
What is the melting point of 1,2-dihydroxybenzene?
The melting point reported for 1,2-dihydroxybenzene is 105 °C (221 °F) (HSDB).
How should 1,2-dihydroxybenzene be stored?
Separated from strong oxidants, food and feedstuffs. Keep in the dark. Ventilation along the floor. (Hazardous Substances Data Bank (HSDB))
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