Substance profile
1,2-Dichlorobenzene
1,2-Dichlorobenzene is a colorless liquid with a pleasant odor.
01 · Identification
What 1,2-Dichlorobenzene is
1,2-Dichlorobenzene is a colorless liquid with a pleasant odor. It boils at 180 °C, melts at -16.7 °C, is miscible with water.
Under the GHS it carries the signal word Warning. It is classed as flammable agents - 2nd degree.
02 · Identifiers
1,2-Dichlorobenzene identifiers and molecular data
1,2-Dichlorobenzene CAS number and EC number
1,2-Dichlorobenzene molecular formula and molecular weight
Other names for 1,2-Dichlorobenzene
- o-dichlorobenzene
03 · GHS classification
1,2-Dichlorobenzene hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
1,2-Dichlorobenzene pictograms and signal word
1,2-Dichlorobenzene hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Acute toxicity - oral GHS chapter 3.1 | Category 4 | H302 | GHS07 |
| Skin corrosion/irritation GHS chapter 3.2 | Category 2 | H315 | GHS07 |
| Serious eye damage/eye irritation GHS chapter 3.3 | Category 2A | H319 | GHS07 |
| Specific target organ toxicity - single exposure GHS chapter 3.8 | Category 3 | H335 | GHS07 |
| Hazardous to the aquatic environment - acute GHS chapter 4.1 | Category 1 | H400 | GHS09 |
| Hazardous to the aquatic environment - chronic GHS chapter 4.1 | Category 1 | H410 | GHS09 |
1,2-Dichlorobenzene hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H302 | Harmful if swallowed. |
| H335 | May cause respiratory irritation. |
| H315 | Causes skin irritation. |
| H319 | Causes serious eye irritation. |
| H400 | Very toxic to aquatic life. |
| H410 | Very toxic to aquatic life with long lasting effects. |
This page lists only the codes assigned to 1,2-Dichlorobenzene. 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-Dichlorobenzene
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-Dichlorobenzene 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-Dichlorobenzene precautionary statements
CLP Annex VI assigns 16 precautionary statements to 1,2-Dichlorobenzene. 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
1,2-Dichlorobenzene 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-дихлоробензен o -дихлоробензен |
| Spanish español | 1,2-Diclorobenceno o -diclorobenceno |
| Czech čeština | 1,2-dichlorbenzen o -dichlorbenzen |
| Danish dansk | 1,2-dichlorbenzen ortho-dichlorbenzen |
| German Deutsch | 1,2-Dichlorbenzol o -Dichlorbenzol |
| Estonian eesti | 1,2-diklorobenseen o -diklorobenseen |
| Greek ελληνικά | 1,2-διχλωροβενζόλιο ο -διχλωροβενζόλιο |
| English English | 1,2-dichlorobenzene o -dichlorobenzene |
| French français | 1,2-dichlorobenzène o -dichlorobenzène |
| Croatian hrvatski | 1,2-diklorbenzen o -diklorbenzen |
| Italian italiano | 1,2-diclorobenzene o -diclorobenzene |
| Latvian latviešu | 1,2-dihlorbenzols o -dihlorbenzols |
| Lithuanian lietuvių | 1,2-dichlorbenzenas o -dichlorbenzenas |
| Hungarian magyar | 1,2-diklórbenzol o -diklórbenzol |
| Maltese Malti | 1,2-diklorobenżen o -diklorobenżen |
| Dutch Nederlands | 1,2-dichloorbenzeen o -dichloorbenzeen |
| Polish polski | 1,2-dichlorobenzen o -dichlorobenzen |
| Portuguese português | 1,2-diclorobenzeno o -diclorobenzeno |
| Romanian română | 1,2-diclorobenzenă o -diclorobenzenă |
| Slovak slovenčina | 1,2-dichlórbenzén orto -dichlórbenzén |
| Slovenian slovenščina | 1,2-diklorobenzen o -diklorobenzen |
| Finnish suomi | 1,2-diklooribentseeni o -diklooribentseeni |
| Swedish svenska | 1,2-diklorbensen o -diklorbensen |
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-Dichlorobenzene GHS label elements
Everything CLP Annex VI fixes for 1,2-Dichlorobenzene, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Warning
1,2-Dichlorobenzene
- Harmful if swallowed.
- May cause respiratory irritation.
- Causes skin irritation.
- Causes serious eye irritation.
- Very toxic to aquatic life.
- Very toxic to aquatic life with long lasting effects.
- Wash … thoroughly after handling.
- 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 ON SKIN:
- IF IN EYES:
- Call a POISON CENTER/doctor/… if you feel unwell.
- 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/…
- Collect spillage.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open 1,2-Dichlorobenzene in the GHS label constructor →
07 · Health hazards
1,2-Dichlorobenzene health hazards and exposure limits
1,2-Dichlorobenzene hazard summary
Liver and kidney injury occur in animal inhalation studies. Inhalation of saturated vapor by mice results in narcosis and death. A case of skin sensitization reported, but sufficient data were not available to recommend a SEN notation. [ACGIH] Inhalation of high concentrations may cause CNS effects; A skin, eye, and respiratory tract irritant; [ICSC]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
1,2-Dichlorobenzene carcinogenicity classification
Under the conditions of these two-year gavage studies, there was no evidence of carcinogenicity of 1,2-dichlorobenzene for male or female F344/N rats or B6C3F1 mice receiving 60 or 120 mg/kg per day.
Source: US National Toxicology Program · TR-255: Toxicology and Carcinogenesis Studies of 1,2-Dichlorobenzene (o-Dichlorobenzene) (CASRN 95-50-1) in F344/N Rats and B6C3F1 Mice (Gavage Studies) (1985 )
Evaluation: There is inadequate evidence in humans for the carcinogenicity of dichlorobenzenes. There is evidence suggesting a lack of carcinogenicity in experimental animals of ortho-dichlorobenzene. ... Overall evaluation: ortho-Dichlorobenzene is not classifiable as to its carcinogenicity to humans (Group 3). /Dichlorobenzenes/
Source: Hazardous Substances Data Bank (HSDB)
Cancer Classification: Group D Not Classifiable as to Human Carcinogenicity
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-Dichlorobenzene occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 50 ppm (300 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| PEL | C 50 ppm (300 mg/m3) | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 50 ppm (300 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | C 50 ppm (300 mg/m3) | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 200 ppm (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 200.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | 200 ppm | Hazardous Substances Data Bank (HSDB) |
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-Dichlorobenzene 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-Dichlorobenzene boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 180.1 °C (356.2 °F) | at 760 mmHg | HSDB |
| 180.56 °C (357 °F) | NIOSH | ||
| 180.5 °C (356.9 °F) | at 760 mmHg | CAMEO |
1,2-Dichlorobenzene melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -16.7 °C (1.9 °F) | HSDB | |
| -17.22 °C (1 °F) | NIOSH |
1,2-Dichlorobenzene density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.3 g/cm³ | NIOSH | |
| 1.3047 g/cm³ | at 21.11 °C | HSDB | |
| 1.3059 g/cm³ | at 20 °C | HSDB |
1,2-Dichlorobenzene solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Miscible with alcohol, ether, benzene. | HSDB | |
| 0.01% | NIOSH | ||
| In water, 156 mg/L at 25 °C | at 25 °C | HSDB |
1,2-Dichlorobenzene vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 1 mmHg | NIOSH | |
| 1 mmHg | at 20 °C | CAMEO | |
| 1.36 mmHg | at 25 °C | HSDB |
1,2-Dichlorobenzene flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 66.11 °C (151 °F) | HSDB | |
| 68 °C (154.4 °F) | HSDB |
1,2-Dichlorobenzene autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 648 °C (1198.4 °F) | HSDB | |
| 647.78 °C (1198 °F) | CAMEO |
1,2-Dichlorobenzene lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 2.2 % by volume | HSDB |
1,2-Dichlorobenzene upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 9.2 % by volume | HSDB |
1,2-Dichlorobenzene vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 5.05 (air = 1) | HSDB | |
| 5.1 (air = 1) | ICSC |
1,2-Dichlorobenzene odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | Odor threshold low= 12.0 mg/cu-m, Odor threshold high= 300.0 mg/cu-m, Irritating concentration= 150.0 mg/cu-m (From table). | HSDB | |
| Odor threshold : 1.8 mg/cu m | HSDB |
1,2-Dichlorobenzene critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 417.2 °C (783 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
1,2-Dichlorobenzene 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-Dichlorobenzene fire potential
Combustible liquid.
Source: Hazardous Substances Data Bank (HSDB)
Odor
Odor of o-dichlorobenzene is detectable by avg person at 50 ppm in air. Odor becomes strong & irritation noticeable at ... concn around 100 ppm. It has fair warning properties at this level but possibility of adaptation should be recognized.
Source: HSDB
10 · Handling and storage
1,2-Dichlorobenzene storage and handling
1,2-Dichlorobenzene safe storage
Separated from aluminium, oxidants and food and feedstuffs.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
1,2-Dichlorobenzene storage conditions
Store in cool, dry, well-ventilated location. Separate from oxidizing materials.
Source: Hazardous Substances Data Bank (HSDB)
1,2-Dichlorobenzene incompatible materials
Strong oxidizers, aluminum, chlorides, acids, acid fumes.
Source: Hazardous Substances Data Bank (HSDB)
1,2-Dichlorobenzene reactivity
O-DICHLOROBENZENE is sensitive to prolonged exposure to light. This chemical can react vigorously with oxidizers. It is incompatible with aluminum and aluminum alloys. It attacks some forms of plastics, rubber and coatings. (NTP, 1992).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check 1,2-Dichlorobenzene in the storage compatibility matrix →
11 · Transport
1,2-Dichlorobenzene UN number and transport classification
Transport classification is a separate system from the GHS classification above. It decides how a package is marked and how a load may be carried; it does not follow from the workplace label, and the workplace label does not follow from it. The entries below are linked by CAS number, never by name.
1,2-Dichlorobenzene under UN 1591 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| o-DICHLOROBENZENE | 6.1 | T1 | III | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 6.1 is “Toxic substances” (ADR 2.1.1.1).
United States · 49 CFR 172.101 Hazardous Materials Table
| Proper shipping name (column 2) | Class or division | PG | Labels (column 6) |
|---|---|---|---|
| o-Dichlorobenzene | 6.1 | III | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 6.1 is “Poisonous materials” (49 CFR 173.2).
12 · Questions
1,2-Dichlorobenzene — frequently asked questions
What is the CAS number of 1,2-Dichlorobenzene?
The CAS number of 1,2-Dichlorobenzene is 95-50-1. Its EC number is 202-425-9.
What does a 1,2-Dichlorobenzene label have to show?
Under CLP Annex VI the label for 1,2-Dichlorobenzene carries the pictograms Exclamation mark and Environment and the signal word is Warning.
Is 1,2-Dichlorobenzene flammable?
CLP Annex VI assigns 1,2-Dichlorobenzene 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 66.11 °C (151 °F) (HSDB).
Is 1,2-Dichlorobenzene a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for 1,2-Dichlorobenzene. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health. IARC places it in Group 3: not classifiable as to its carcinogenicity to humans.
What is the exposure limit for 1,2-Dichlorobenzene?
The US occupational exposure limit reported for 1,2-Dichlorobenzene is 50 ppm (300 mg/m³) (Occupational Safety and Health Administration (OSHA)). 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-Dichlorobenzene?
The boiling point reported for 1,2-Dichlorobenzene is 180.1 °C (356.2 °F), at 760 mmHg (HSDB).
What is the melting point of 1,2-Dichlorobenzene?
The melting point reported for 1,2-Dichlorobenzene is -16.7 °C (1.9 °F) (HSDB).
How should 1,2-Dichlorobenzene be stored?
Store in cool, dry, well-ventilated location. Separate from oxidizing materials. (Hazardous Substances Data Bank (HSDB))
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