Substance profile
Benzoyl Peroxide
Benzoyl Peroxide is crystals with a faint, benzaldehyde-like odor.
01 · Identification
What Benzoyl Peroxide is
Benzoyl Peroxide is crystals with a faint, benzaldehyde-like odor. Its molecular formula is C14H10O4 and its molecular weight is 242.23 g/mol. It melts at 105 °C.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 4th degree.
02 · Identifiers
Benzoyl Peroxide identifiers and molecular data
Benzoyl Peroxide CAS number and EC number
Benzoyl Peroxide molecular formula and molecular weight
Other names for Benzoyl Peroxide
- dibenzoyl peroxide
03 · GHS classification
Benzoyl Peroxide hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Benzoyl Peroxide pictograms and signal word
Benzoyl Peroxide hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Organic peroxides or Self-reactive substances and mixtures | Category Type B | H241 | — |
| Serious eye damage/eye irritation GHS chapter 3.3 | Category 2A | H319 | GHS07 |
| Skin sensitisation GHS chapter 3.4 | Category 1 or 1A or 1B | H317 | 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 |
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.
Benzoyl Peroxide hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H241 | Heating may cause a fire or explosion. |
| H319 | Causes serious eye irritation. |
| H317 | May cause an allergic skin reaction. |
| H400 | Very toxic to aquatic life. |
| H410 | Very toxic to aquatic life with long lasting effects. |
This page lists only the codes assigned to Benzoyl Peroxide. 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 Benzoyl Peroxide
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 Benzoyl Peroxide 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
Benzoyl Peroxide precautionary statements
CLP Annex VI assigns 12 precautionary statements to Benzoyl Peroxide. 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
Benzoyl Peroxide 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 | дибензоилпероксид бензоилпероксид |
| Spanish español | Peróxido de dibenzoílo peróxido de benzoílo |
| Czech čeština | dibenzoylperoxid benzoylperoxid |
| Danish dansk | dibenzoylperoxid benzoylperoxid |
| German Deutsch | Dibenzoylperoxid Benzoylperoxid |
| Estonian eesti | dibensoüülperoksiid bensoüülperoksiid |
| Greek ελληνικά | διβενζοϋλυπεροξείδιο βενζοϋλυπεροξείδιο |
| English English | dibenzoyl peroxide benzoyl peroxide |
| French français | peroxyde de dibenzoyle peroxyde de benzoyle |
| Croatian hrvatski | dibenzoil peroksid benzoil peroksid |
| Italian italiano | perossido di dibenzoile perossido di benzoile |
| Latvian latviešu | dibenzoilperoksīds benzoilperoksīds |
| Lithuanian lietuvių | dibenzoilperoksidas benzoilperoksidas |
| Hungarian magyar | dibenzoil-peroxid benzoil-peroxid |
| Maltese Malti | perossidu tad-dibenżojl perossidu tal-benżojl |
| Dutch Nederlands | dibenzoylperoxide benzoylperoxide |
| Polish polski | nadtlenek dibenzoilu nadtlenek benzoilu |
| Portuguese português | peróxido de dibenzoílo peróxido de benzoílo |
| Romanian română | peroxid de dibenzoil peroxid de benzoil |
| Slovak slovenčina | dibenzoylperoxid benzoylperoxid |
| Slovenian slovenščina | dibenzoil peroksid benzoil peroksid |
| Finnish suomi | dibentsoyyliperoksidi bentsoyyliperoksidi |
| Swedish svenska | dibensoylperoxid bensoylperoxid |
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
Benzoyl Peroxide GHS label elements
Everything CLP Annex VI fixes for Benzoyl Peroxide, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Benzoyl Peroxide
- Heating may cause a fire or explosion.
- Causes serious eye irritation.
- May cause an allergic skin reaction.
- Very toxic to aquatic life.
- Very toxic to aquatic life with long lasting effects.
- Avoid breathing dust/fume/gas/mist/vapours/spray.
- Wash … thoroughly after handling.
- Contaminated work clothing should not be allowed out of the workplace.
- Avoid release to the environment.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF IN EYES:
- Get medical advice/attention.
- If skin irritation or rash occurs:
- If eye irritation persists:
- Remove contact lenses, if present and easy to do. Continue rinsing.
- Collect spillage.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Benzoyl Peroxide in the GHS label constructor →
07 · Health hazards
Benzoyl Peroxide health hazards and exposure limits
Benzoyl Peroxide hazard summary
Benzoyl peroxide is a skin irritant and infrequent sensitizer. It may cause allergic contact dermatitis in dentists using acrylate cements and in bakers handling bleached flour. [Marks, p. 188] If left on clothes, can cause reddening of the skin; [CHRIS] A skin, eye, and respiratory tract irritant; [ICSC]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Benzoyl Peroxide carcinogenicity classification
Evaluation: There is inadequate evidence in humans for the carcinogenicity of benzoyl peroxide. There is limited evidence in experimental animals for the carcinogenicity of benzoyl peroxide. Overall evaluation: Benzoyl peroxide is not classifiable as to its carcinogenicity to humans (Group 3).
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.
Benzoyl Peroxide occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 5.0 [mg/m3] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| PEL | 5 mg/m³ | Occupational Safety and Health Administration (OSHA) |
| PEL | TWA 5 mg/m3 | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 5 mg/m³ | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 5 mg/m3 | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 1500 mg/m3 (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 1500.0 [mg/m3] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | Excerpts from Documentation for IDLHs: Human data: Concentrations of 12 mg/m3 and higher have resulted in pronounced irritation of the nose and throat [Moskowitz and Grabois 1950]. | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
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
Benzoyl Peroxide 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.
Benzoyl Peroxide boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | Decomposes explosively | decomposes | NIOSH |
| Decomposes explosively (NTP, 1992) | decomposes | CAMEO | |
| decomposes explosively | decomposes | OSHA |
Benzoyl Peroxide melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 104.5 °C (220.1 °F) | HSDB | |
| 102.78 °C (217 °F) | NIOSH |
Benzoyl Peroxide density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.33 g/cm³ | NIOSH | |
| 1.3 g/cm³ | ICSC | ||
| 1.334 g/cm³ | at 25 °C | HSDB |
Benzoyl Peroxide solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Sparingly soluble in water | HSDB | |
| Slightly soluble in water | HSDB | ||
| In water, 9.10 mg/L at 25 °C | at 25 °C | HSDB |
Benzoyl Peroxide vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 1 mmHg | below this value | NIOSH |
| 0.1 mmHg | below this value, at 20 °C | HSDB |
Benzoyl Peroxide flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 80 °C (176 °F) | HSDB |
Benzoyl Peroxide autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 80 °C (176 °F) | HSDB |
Benzoyl Peroxide lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | May explode when heated. | HSDB | |
| Combustible Solid (easily ignited and burns very rapidly). | NIOSH |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Benzoyl Peroxide 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.
Benzoyl Peroxide fire potential
This chemical is a highly flammable liquid.
Source: Hazardous Substances Data Bank (HSDB)
Fire and explosion
Benzoyl peroxide has been reported to explode for apparently no specific reason. Friction while opening bottles has caused other explosions. Purification of benzoyl peroxide in hot chloroform solutions has also resulted in several explosions. Purification in cold chloroform by addition of methanol is without danger.
Source: HSDB
10 · Handling and storage
Benzoyl Peroxide storage and handling
Benzoyl Peroxide safe storage
Fireproof. Separated from combustible substances and reducing agents. Store only in original packaging. See Chemical Dangers.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Benzoyl Peroxide storage conditions
Keep container tightly closed in a dry and well-ventilated place. Storage class (TRGS 510): Other explosive hazardous materials.
Source: Hazardous Substances Data Bank (HSDB)
Benzoyl Peroxide incompatible materials
Incompatible materials: Alcohols, metals.
Source: Hazardous Substances Data Bank (HSDB)
Planning storage for a mix of chemicals? Check Benzoyl Peroxide in the storage compatibility matrix →
11 · Questions
Benzoyl Peroxide — frequently asked questions
What is the CAS number of Benzoyl Peroxide?
The CAS number of Benzoyl Peroxide is 94-36-0. Its EC number is 202-327-6.
What is the chemical formula of Benzoyl Peroxide?
The molecular formula of Benzoyl Peroxide is C14H10O4 and its molecular weight is 242.23 g/mol.
What does a Benzoyl Peroxide label have to show?
Under CLP Annex VI the label for Benzoyl Peroxide carries the pictograms Exploding bomb, Flame, Exclamation mark and Environment and the signal word is Danger.
Is Benzoyl Peroxide flammable?
Yes. CLP Annex VI assigns Benzoyl Peroxide H241 — heating may cause a fire or explosion. The flash point reported for it is 80 °C (176 °F) (HSDB).
Is Benzoyl Peroxide a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Benzoyl Peroxide. 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 Benzoyl Peroxide?
The US occupational exposure limit reported for Benzoyl Peroxide is 5.0 [mg/m3] (Haz-Map, Information on Hazardous Chemicals and Occupational Diseases). 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 Benzoyl Peroxide?
The boiling point reported for Benzoyl Peroxide is Decomposes explosively, decomposes (NIOSH).
What is the melting point of Benzoyl Peroxide?
The melting point reported for Benzoyl Peroxide is 104.5 °C (220.1 °F) (HSDB).
How should Benzoyl Peroxide be stored?
Keep container tightly closed in a dry and well-ventilated place. Storage class (TRGS 510): Other explosive hazardous materials. (Hazardous Substances Data Bank (HSDB))
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