Substance profile
Pentachlorophenol
Pentachlorophenol is a white monoclinic, crystalline solid with a phenolic odor.
01 · Identification
What Pentachlorophenol is
Pentachlorophenol is a white monoclinic, crystalline solid with a phenolic odor. Its molecular formula is C6HCl5O and its molecular weight is 266.3 g/mol. It boils at 310 °C, melts at 174 °C, is slightly soluble in water.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
02 · Identifiers
Pentachlorophenol identifiers and molecular data
Pentachlorophenol CAS number and EC number
Pentachlorophenol molecular formula and molecular weight
03 · GHS classification
Pentachlorophenol hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Pentachlorophenol pictograms and signal word
Pentachlorophenol 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 |
| Acute toxicity - inhalation GHS chapter 3.1 | Category 1 or 2 | H330 | 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 |
| Carcinogenicity GHS chapter 3.6 | Category 2 | H351 | GHS08 |
| 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 |
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.
Pentachlorophenol hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H351 | Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H330 | Fatal if inhaled. |
| H311 | Toxic in contact with skin. |
| H301 | Toxic 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 Pentachlorophenol. 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 Pentachlorophenol
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 Pentachlorophenol 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
Pentachlorophenol precautionary statements
CLP Annex VI assigns 21 precautionary statements to Pentachlorophenol. 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
Pentachlorophenol 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 | пентахлорофенол |
| Spanish español | Pentaclorofenol |
| Czech čeština | pentachlorfenol |
| Danish dansk | pentachlorphenol |
| German Deutsch | Pentachlorphenol PCP |
| Estonian eesti | pentaklorofenool |
| Greek ελληνικά | πενταχλωροφαινόλη |
| English English | pentachlorophenol |
| French français | pentachlorophénol |
| Croatian hrvatski | pentaklorfenol |
| Italian italiano | pentaclorofenolo |
| Latvian latviešu | pentahlorfenols |
| Lithuanian lietuvių | pentachlorfenolis |
| Hungarian magyar | pentaklórfenol |
| Maltese Malti | pentaklorofenol |
| Dutch Nederlands | pentachloorfenol |
| Polish polski | pentachlorofenol |
| Portuguese português | pentaclorofenol |
| Romanian română | pentaclorofenol |
| Slovak slovenčina | pentachlórfenol |
| Slovenian slovenščina | pentaklorofenol |
| Finnish suomi | pentakloorifenoli |
| Swedish svenska | pentaklorfenol |
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
Pentachlorophenol GHS label elements
Everything CLP Annex VI fixes for Pentachlorophenol, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Pentachlorophenol
- Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Fatal if inhaled.
- Toxic in contact with skin.
- Toxic 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.
- Obtain special instructions before use.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Wash … thoroughly after handling.
- Do not eat, drink or smoke when using this product.
- Use only outdoors or in a well-ventilated area.
- Avoid release to the environment.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF ON SKIN:
- IF INHALED:
- 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/…
- Collect spillage.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Pentachlorophenol in the GHS label constructor →
07 · Health hazards
Pentachlorophenol health hazards and exposure limits
Pentachlorophenol hazard summary
Pentachlorophenol is a manufactured chemical that does not occur naturally. Pure pentachlorophenol exists as colorless crystals. Impure pentachlorophenol (the form usually found at hazardous waste sites) is dark gray to brown and exists as dust, beads, or flakes. Humans are usually exposed to impure pentachlorophenol (also called technical grade pentachlorophenol). Pentachlorophenol was widely used as a pesticide and wood preservative. Since 1984, the purchase and use of pentachlorophenol has been restricted to certified applicators. It is no longer available to the general public. It is still used industrially as a wood preservative for utility poles, railroad ties, and wharf pilings.
Source: Agency for Toxic Substances and Disease Registry (ATSDR)
Pentachlorophenol carcinogenicity classification
Under the conditions of this 2-year feed study, there was no evidence of carcinogenic activity of pentachlorophenol in male or female F344/N rats fed diets containing 200, 400, or 600 ppm. There was some evidence of carcinogenic activity of pentachlorophenol in male F344/N rats given feed containing 1,000 ppm for 1 year followed by control feed for 1 year (stop-exposure study), based on increased incidences of mesothelioma and nasal squamous cell carcinoma. There was no evidence of carcinogenic activity of pentachlorophenol in female rats given feed containing 1,000 ppm for 1 year and maintained on control feed for 1 year.
Source: US National Toxicology Program · TR-483: Toxicology and Carcinogenesis Studies of Pentachlorophenol in F344/N Rats (Feed Studies) (1999 )
Evaluation: There is limited evidence in humans for the carcinogenicity of combined exposures to polychlorophenols and their sodium salts. ... There is sufficient evidence in experimental animals for the carcinogenicity of pentachlorophenol. Overall evaluation: Combined exposures to polychlorophenols or to their sodium salts are possibly carcinogenic to humans (Group 2B). /Polychlorophenols & sodium salts/
Source: Hazardous Substances Data Bank (HSDB)
Cancer Classification: Group B2 Probable Human Carcinogen
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.
Pentachlorophenol occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 0.5 [mg/m3] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| PEL | 0.5 mg/m³ | Occupational Safety and Health Administration (OSHA) |
| PEL | TWA 0.5 mg/m3 [skin] | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 0.5 mg/m³ | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 0.5 mg/m3 [skin] | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 2.5 mg/m3 (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 2.5 mg/cu m | Hazardous Substances Data Bank (HSDB) |
| IDLH | 2.5 mg/m³ | Occupational Safety and Health Administration (OSHA) |
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
Pentachlorophenol 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.
Pentachlorophenol boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 309.5 °C (589.1 °F) | range, midpoint shown | HSDB |
| 309.44 °C (589 °F) | range, midpoint shown, at 760 mmHg | CAMEO | |
| 308.89 °C (588 °F) | decomposes | NIOSH |
Pentachlorophenol melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 174 °C (345.2 °F) | HSDB | |
| 190 °C (374 °F) | NIOSH | ||
| 191.11 °C (376 °F) | CAMEO |
Pentachlorophenol density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.978 g/cm³ | HSDB | |
| 1.98 g/cm³ | NIOSH |
Pentachlorophenol solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Slightly soluble in ligroin; very soluble in diethyl ether | HSDB | |
| Sol in dilute alkali, carbitol, cellosolve | HSDB | ||
| Soluble in most organic solvents, for example acetone 215 g/L at 20 °C. Slightly soluble in ... parafins. | at 20 °C | HSDB |
Pentachlorophenol vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 0.00011 mmHg | at 20 °C | CAMEO |
| 0.00011 mmHg | at 25 °C | HSDB | |
| 0.0001 mmHg | at 25 °C | NIOSH |
Pentachlorophenol autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | Not flammable (USCG, 1999) | CAMEO |
Pentachlorophenol lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | Noncombustible Solid | NIOSH |
Pentachlorophenol vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 9.2 (air = 1) | HSDB |
Pentachlorophenol odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | Odor thresholds for PCP soln at 30 deg and 60 °C were 857 and 12,000 ug/l, respectively. | HSDB | |
| Detection: 1.6 mg/l. | HSDB |
Pentachlorophenol corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | Noncorrosive in absence of moisture | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Pentachlorophenol 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.
Pentachlorophenol fire potential
Not combustible but if involved in a fire decomposes to produce hydrogen chloride and other irritants and toxic gases. May be in hydrocarbon solution.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Pentachlorophenol storage and handling
Pentachlorophenol safe storage
Provision to contain effluent from fire extinguishing. Separated from strong oxidants and food and feedstuffs. Keep in a well-ventilated room.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Pentachlorophenol storage conditions
Where possible, automatically transfer material from drums or other storage containers to process containers. Sources of ignition such as smoking and open flames are prohibited where this chemical is handled, used, or stored. Metal containers involving the transfer of this chemical should be grounded and bonded. A regulated, marked area should be established where this chemical is handled, used or stored ...
Source: Hazardous Substances Data Bank (HSDB)
Pentachlorophenol incompatible materials
Contact with strong oxidizers may cause fires or explosions.
Source: Hazardous Substances Data Bank (HSDB)
Pentachlorophenol reactivity
PENTACHLOROPHENOL may react with strong oxidizing agents. Incompatible with strong bases, acid chlorides and acid anhydrides. Forms salts with alkaline metals. Solutions in oil cause natural rubber to deteriorate, but synthetic rubber may be used in equipment and for protective clothing (NTP, 1992).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Pentachlorophenol in the storage compatibility matrix →
11 · Transport
Pentachlorophenol 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.
Pentachlorophenol under UN 3155 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| PENTACHLOROPHENOL | 6.1 | T2 | II | |
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) |
|---|---|---|---|
| Pentachlorophenol | 6.1 | II | |
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
Pentachlorophenol — frequently asked questions
What is the CAS number of Pentachlorophenol?
The CAS number of Pentachlorophenol is 87-86-5. Its EC number is 201-778-6.
What is the chemical formula of Pentachlorophenol?
The molecular formula of Pentachlorophenol is C6HCl5O and its molecular weight is 266.3 g/mol.
What does a Pentachlorophenol label have to show?
Under CLP Annex VI the label for Pentachlorophenol carries the pictograms Skull and crossbones, Health hazard and Environment and the signal word is Danger.
Is Pentachlorophenol flammable?
CLP Annex VI assigns Pentachlorophenol 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.
Is Pentachlorophenol a carcinogen?
CLP Annex VI assigns Pentachlorophenol H351 — suspected of causing cancer. That is category 2: the evidence points that way but is not conclusive. IARC places it in Group 1: carcinogenic to humans.
What is the exposure limit for Pentachlorophenol?
The US occupational exposure limit reported for Pentachlorophenol is 0.5 [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 Pentachlorophenol?
The boiling point reported for Pentachlorophenol is 309.5 °C (589.1 °F), range, midpoint shown (HSDB).
What is the melting point of Pentachlorophenol?
The melting point reported for Pentachlorophenol is 174 °C (345.2 °F) (HSDB).
How should Pentachlorophenol be stored?
Where possible, automatically transfer material from drums or other storage containers to process containers. Sources of ignition such as smoking and open flames are prohibited where this chemical is handled, used, or stored. Metal containers involving the transfer of this chemical should be grounded and bonded. A regulated, marked area should be established where this chemical is handled, used or stored ... (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Pentachlorophenol
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