Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Substance profile

Chlorpyrifos

Chlorpyrifos is white granular crystals with a mild mercaptan odor.

CAS 2921-88-2 Danger

01 · Identification

What Chlorpyrifos is

Chlorpyrifos is white granular crystals with a mild mercaptan odor. It boils at 160 °C, melts at 42.2 °C.

Under the GHS it carries the signal word Danger.

02 · Identifiers

Chlorpyrifos identifiers and molecular data

Chlorpyrifos CAS number and EC number

CAS number2921-88-2
EC number220-864-4
Index number (CLP Annex VI)015-084-00-4

Other names for Chlorpyrifos

  • chlorpyrifos (ISO)
  • O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate

03 · GHS classification

Chlorpyrifos hazard classification

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Chlorpyrifos pictograms and signal word

Signal wordDanger

Chlorpyrifos hazard class and category

GHS hazard classes Chlorpyrifos falls into
Hazard class Category From code Pictogram
Acute toxicity - oral GHS chapter 3.1 Category 3 H301 GHS06
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

Chlorpyrifos hazard statements (H-codes)

Hazard statements assigned to Chlorpyrifos
CodeHazard statement
H301 Toxic if swallowed.
H400 Very toxic to aquatic life.
H410 Very toxic to aquatic life with long lasting effects.

This page lists only the codes assigned to Chlorpyrifos. 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 Chlorpyrifos

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 Chlorpyrifos 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

Chlorpyrifos precautionary statements

CLP Annex VI assigns 7 precautionary statements to Chlorpyrifos. 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.

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

Chlorpyrifos 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 хлорпирифос (ISO) O , O -диетилов О -3,5,6-трихлоро-2-пиридилов фосфоротиоат
Spanish español Clorpirifós (ISO) fosforotioato de O , O -dietilo y O -3,5,6-tricloro-2-piridilo
Czech čeština chlorpyrifos (ISO) O, O -diethyl- O -(3,5,6-trichlor-2-pyridyl)-fosforothioát
Danish dansk chlorpyrifos (ISO) O, O- diethyl- O- 3,5,6-trichlor-2-pyridylthiophosphat
German Deutsch Chlorpyrifos (ISO) O, O -Diethyl- O -3,5,6-Trichlor-2- pyridylphosphorothioat
Estonian eesti kloorpürifoss (ISO) O , O -dietüül- O -3,5,6-trikloro-2-püridüülfosforotioaat
Greek ελληνικά chlorpyrifos (χλωροπυριφός) (ISO) θειοφωσφορικό O , O -διαιθύλιο O -3,5,6-τριχλωρο-2-πυριδύλιο
English English chlorpyrifos (ISO) O , O -diethyl O -3,5,6-trichloro-2-pyridyl phosphorothioate
French français chlorpyrifos (ISO) phosphorothioate de O , O -diéthyle et de O -3,5,6-trichloro-2-pyridyle
Croatian hrvatski klorpirifos (ISO) O , O -dietil- O -3,5,6-triklor-2-piridil-fosforotioat
Italian italiano clorpirifos (ISO) tiofosfato di O, O-dietile e O-3,5,6-tricloro-2-piridile
Latvian latviešu hlorpirifoss (ISO) O , O -dietil- O -3,5,6-trihlor-2-piridilfosfortioāts
Lithuanian lietuvių chlorpirifosas (ISO) O , O -dietil- O -3,5,6-trichlor-2-piridiltiofosfatas
Hungarian magyar klórpirifosz (ISO) O , O -dietil- O -3,5,6-triklór-2-piridil-tiofoszfát
Maltese Malti klorpirifos (ISO) fosforotijoat ta’ O , O -dietil O -3,5,6-trikloro-2-piridil
Dutch Nederlands chloorpyrifos (ISO) O , O -diëthyl- O -3,5,6-trichloor-2-pyridylthiofosfaat
Polish polski chloropiryfos (ISO) tiofosforan O , O -dietylu- O -3,5,6-trichloro-2-pirydylu
Portuguese português clorpirifos (ISO) tiofosfato de O , O -dietilo e de O -3,5,6-tricloro-2-piridilo
Romanian română clorpirifos (ISO) tiofosfat de O, O -dietil și de O -3,5,6-tricloro-2-piridil
Slovak slovenčina chlórpyrifos (ISO) O, O -dietyl- O -(3,5,6-trichlór-2-pyridyl)- fosforotioát
Slovenian slovenščina klorpirifos (ISO) O , O -dietil O -3,5,6-trikloro-2-piridil fosforotioat
Finnish suomi klooripyrifossi (ISO) O , O -dietyyli- O -3,5,6-trikloori-2-pyridyylifosforitioaatti
Swedish svenska klorpyrifos (ISO) O , O -dietyl- O -3,5,6-triklor-2-pyridylfosfortioat

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

Chlorpyrifos GHS label elements

Everything CLP Annex VI fixes for Chlorpyrifos, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.

GHS06 Skull and crossbones pictogramGHS09 Environment pictogram

Danger

Chlorpyrifos

  • Toxic if swallowed.
  • Very toxic to aquatic life.
  • Very toxic to aquatic life with long lasting effects.
  • Do not eat, drink or smoke when using this product.
  • Avoid release to the environment.
  • IF SWALLOWED:
  • Immediately call a POISON CENTER/doctor/
  • 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 Chlorpyrifos in the GHS label constructor →

07 · Health hazards

Chlorpyrifos health hazards and exposure limits

Chlorpyrifos hazard summary

Chlorpyrifos is an insecticide that is a white crystal-like solid with a strong odor. It does not mix well with water, so it is usually mixed with oily liquids before it is applied to crops or animals. It may also be applied to crops in a capsule form. Chlorpyrifos has been widely used in homes and on farms. In the home, it is used to control cockroaches, fleas, and termites; it is also used in some pet flea and tick collars. On the farm, it is used to control ticks on cattle and as a spray to control crop pests.

Source: Agency for Toxic Substances and Disease Registry (ATSDR)

Chlorpyrifos carcinogenicity classification

Cancer Classification: Group E Evidence of Non-carcinogenicity for 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.

Chlorpyrifos occupational exposure limits

US occupational exposure limits reported for Chlorpyrifos. PEL is enforceable (OSHA), REL is a recommendation (NIOSH), IDLH is the concentration at which escape becomes impossible without injury.
Limit Value Source
PEL none See Appendix G The National Institute for Occupational Safety and Health (NIOSH)
REL 0.2 mg/m³ Occupational Safety and Health Administration (OSHA)
REL TWA 0.2 mg/m3 ST 0.6 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

Chlorpyrifos 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.

Chlorpyrifos boiling point

Property Value Conditions Source
Boiling point 160 °C (320 °F) HSDB
160 °C (320 °F) decomposes NIOSH
160 °C (320 °F) decomposes, at 760 mmHg CAMEO

Chlorpyrifos melting point

Property Value Conditions Source
Melting point 42.22 °C (108 °F) NIOSH
41.5 °C (106.7 °F) range, midpoint shown HSDB

Chlorpyrifos density

Property Value Conditions Source
Density 1.4 g/cm³ ICSC
1.44 g/cm³ at 20 °C HSDB

Chlorpyrifos solubility

Property Value Conditions Source
Solubility In water, 1.12 mg/L at 24 °C at 24 °C HSDB
In water, 0.39 mg/L at 19.5 °C at 19.5 °C, OECD 105 method HSDB
In water, 1.4 mg/L at 25 °C at 25 °C HSDB

Chlorpyrifos vapor pressure

Property Value Conditions Source
Vapor pressure 0.00002 mmHg NIOSH
0.0000202 mmHg at 25 °C HSDB
0.0000187 mmHg at 25 °C CAMEO

Chlorpyrifos flash point

Property Value Conditions Source
Flash point 27.78 °C (82 °F) HSDB
30.56 °C (87 °F) HSDB

Chlorpyrifos lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) Combustible Solid NIOSH

Chlorpyrifos vapor density

Property Value Conditions Source
Vapor density 12.09 (air = 1) calculated CAMEO
12.09 (air = 1) OSHA

Chlorpyrifos corrosivity

Property Value Conditions Source
Corrosivity Corrosive to copper and brass HSDB

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

09 · Handling and storage

Chlorpyrifos storage and handling

Chlorpyrifos safe storage

Store only in original container. Keep in a well-ventilated room. Separated from food and feedstuffs. Provision to contain effluent from fire extinguishing. Store in an area without drain or sewer access.

Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Chlorpyrifos storage conditions

Do not contaminate water, food or feed by storage or disposal. Open dumping is prohibited. ... Store in original container in secured dry storage area. Prevent cross-contamination with other pesticides and fertilizers. Do not store above 1002F for extended periods of time. If container is damaged or spills occurs, use product immediately or dispose of product ... . /Dursban W/

Source: Hazardous Substances Data Bank (HSDB)

Chlorpyrifos incompatible materials

Incompartible Materials: Brass

Source: Hazardous Substances Data Bank (HSDB)

Chlorpyrifos reactivity

CHLORPYRIFOS is sensitive to heat and is decomposed by moisture. This chemical is hydrolyzed by strong alkalis. It is corrosive to copper and brass. It is also corrosive to copper alloys. It reacts with water and most reactive hydrogen compounds. The rate of hydrolysis in water increases with pH, with temperature and with the presence of copper and possibly other metals that can form chelates. (NTP, 1992)

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Chlorpyrifos in the storage compatibility matrix →

10 · Questions

Chlorpyrifos — frequently asked questions

What is the CAS number of Chlorpyrifos?

The CAS number of Chlorpyrifos is 2921-88-2. Its EC number is 220-864-4.

What does a Chlorpyrifos label have to show?

Under CLP Annex VI the label for Chlorpyrifos carries the pictograms Skull and crossbones and Environment and the signal word is Danger.

Is Chlorpyrifos flammable?

CLP Annex VI assigns Chlorpyrifos 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 27.78 °C (82 °F) (HSDB).

Is Chlorpyrifos a carcinogen?

CLP Annex VI records no harmonised carcinogenicity classification for Chlorpyrifos. 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.

What is the exposure limit for Chlorpyrifos?

The US occupational exposure limit reported for Chlorpyrifos 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 Chlorpyrifos?

The boiling point reported for Chlorpyrifos is 160 °C (320 °F) (HSDB).

What is the melting point of Chlorpyrifos?

The melting point reported for Chlorpyrifos is 42.22 °C (108 °F) (NIOSH).

How should Chlorpyrifos be stored?

Do not contaminate water, food or feed by storage or disposal. Open dumping is prohibited. ... Store in original container in secured dry storage area. Prevent cross-contamination with other pesticides and fertilizers. Do not store above 1002F for extended periods of time. If container is damaged or spills occurs, use product immediately or dispose of product ... . /Dursban W/ (Hazardous Substances Data Bank (HSDB))

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