Substance profile
2,4-D (ISO)
2,4-D (ISO) is a white to yellow crystalline powder and is odorless.
01 · Identification
What 2,4-D (ISO) is
2,4-D (ISO) is a white to yellow crystalline powder and is odorless. It melts at 138 °C.
Under the GHS it carries the signal word Danger. It is classed as carcinogens.
02 · Identifiers
2,4-D (ISO) identifiers and molecular data
2,4-D (ISO) CAS number and EC number
2,4-D (ISO) molecular formula and molecular weight
Other names for 2,4-D (ISO)
- 2,4-dichlorophenoxyacetic acid
03 · GHS classification
2,4-D (ISO) hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
2,4-D (ISO) pictograms and signal word
2,4-D (ISO) hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Acute toxicity - oral GHS chapter 3.1 | Category 4 | H302 | GHS07 |
| Serious eye damage/eye irritation GHS chapter 3.3 | Category 1 | H318 | GHS05 |
| Skin sensitisation GHS chapter 3.4 | Category 1 or 1A or 1B | H317 | GHS07 |
| Specific target organ toxicity - single exposure GHS chapter 3.8 | Category 3 | H335 | GHS07 |
| Hazardous to the aquatic environment - chronic GHS chapter 4.1 | Category 3 | H412 | — |
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.
2,4-D (ISO) hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H302 | Harmful if swallowed. |
| H335 | May cause respiratory irritation. |
| H318 | Causes serious eye damage. |
| H317 | May cause an allergic skin reaction. |
| H412 | Harmful to aquatic life with long lasting effects. |
This page lists only the codes assigned to 2,4-D (ISO). 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 2,4-D (ISO)
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 2,4-D (ISO) 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
2,4-D (ISO) precautionary statements
CLP Annex VI assigns 14 precautionary statements to 2,4-D (ISO). 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
2,4-D (ISO) 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 | 2,4-D (ISO) 2,4-дихлорофеноксиоцетна киселина |
| Spanish español | 2,4-D (ISO) ácido 2,4-diclorofenoxiacético |
| Czech čeština | 2,4-D (ISO) 2,4-dichlorfenoxyoctová kyselina |
| Danish dansk | 2,4-D (ISO) 2,4-dichlorphenoxyeddikesyre |
| German Deutsch | 2,4-D (ISO) 2,4-Dichlorphenoxyessigsäure |
| Estonian eesti | 2,4-D (ISO) 2,4-diklorofenoksüäädikhape |
| Greek ελληνικά | 2,4-D (ISO) 2,4-διχλωροφαινοξυοξικό οξύ |
| English English | 2,4-D (ISO) 2,4-dichlorophenoxyacetic acid |
| French français | 2,4-D (ISO) acide 2,4-dichlorophénoxyacétique |
| Croatian hrvatski | 2,4-D (ISO) 2,4-diklorfenoksioctena kiselina |
| Italian italiano | 2,4-D (ISO) acido 2,4-diclorofenossiacetico |
| Latvian latviešu | 2,4-D (ISO) 2,4-dihlorfenoksietiķskābe |
| Lithuanian lietuvių | 2,4-D (ISO) 2,4-dichlorfenoksiacto rūgštis |
| Hungarian magyar | 2,4-D (ISO) 2,4-diklórfenoxiecetsav |
| Maltese Malti | 2,4-D (ISO) aċidu 2,4-diklorofenossiaċetiku |
| Dutch Nederlands | 2,4-D (ISO) 2,4-dichloorfenoxyazijnzuur |
| Polish polski | 2,4-D (ISO) kwas (2,4-dichlorofenoksy)octowy |
| Portuguese português | 2,4-D (ISO) ácido 2,4-diclorofenoxiacético |
| Romanian română | 2,4-D (ISO) acid 2,4-diclorofenoxiacetic |
| Slovak slovenčina | 2,4-D (ISO) kyselina (2,4-dichlórfenoxy)octová |
| Slovenian slovenščina | 2,4-D (ISO) 2,4-diklorofenoksiocetna kislina |
| Finnish suomi | 2,4-D (ISO) 2,4-dikloorifenoksietikkahappo |
| Swedish svenska | 2,4-D (ISO) 2,4-diklorfenoxiättiksyra |
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
2,4-D (ISO) GHS label elements
Everything CLP Annex VI fixes for 2,4-D (ISO), laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
2,4-D (ISO)
- Harmful if swallowed.
- May cause respiratory irritation.
- Causes serious eye damage.
- May cause an allergic skin reaction.
- Harmful to aquatic life with long lasting effects.
- Avoid breathing dust/fume/gas/mist/vapours/spray.
- Do not eat, drink or smoke when using this product.
- 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 SWALLOWED:
- IF IN EYES:
- Immediately call a POISON CENTER/doctor/…
- Call a POISON CENTER/doctor/… if you feel unwell.
- Get medical advice/attention.
- Rinse mouth.
- If skin irritation or rash occurs:
- Remove contact lenses, if present and easy to do. Continue rinsing.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open 2,4-D (ISO) in the GHS label constructor →
07 · Health hazards
2,4-D (ISO) health hazards and exposure limits
2,4-D (ISO) hazard summary
2,4-Dichlorophenoxyacetic acid (2,4-D) does not occur naturally in the environment. 2,4-D is the active ingredient in many products used in the United States and throughout the world as an herbicide to kill weeds on land and in the water. There are nine forms of 2,4-D that can be used as an herbicide and it is typically sold as a powder or in a liquid form.
Source: Agency for Toxic Substances and Disease Registry (ATSDR)
2,4-D (ISO) carcinogenicity classification
Cancer Classification: Group D Not Classifiable as to Human Carcinogenicity
Source: Hazardous Substances Data Bank (HSDB)
Classification of carcinogenicity: 1) evidence in humans: limited; overall summary evaluation of carcinogenic risk to humans is Group 2B: The agent is possibly carcinogenic to humans. /SRP: The older literature indicated that these compounds were carcinogenic. It was discovered that this was due to contamination, including dioxin./ /Chlorophenoxy herbicides; From table/
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.
2,4-D (ISO) occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 10.0 [mg/m3] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| PEL | 10 mg/m³ | Occupational Safety and Health Administration (OSHA) |
| PEL | TWA 10 mg/m3 | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 10 mg/m³ | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 10 mg/m3 | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 100 mg/m3 (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 100.0 [mg/m3] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | 100 mg/cu m | 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
2,4-D (ISO) 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.
2,4-D (ISO) boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 160 °C (320 °F) | at 4 mmHg (reduced pressure) | HSDB |
| Decomposes | decomposes | NIOSH | |
| Decomposes (NTP, 1992) | decomposes | CAMEO |
2,4-D (ISO) melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 138 °C (280.4 °F) | HSDB | |
| 137.78 °C (280 °F) | NIOSH |
2,4-D (ISO) density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.57 g/cm³ | NIOSH | |
| 1.563 g/cm³ | at 20 °C | CAMEO | |
| 1.42 g/cm³ | at 25 °C | HSDB |
2,4-D (ISO) solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Needles from alcohol. Solubility in water: 3.5% | HSDB | |
| In water, 677 ppm at 25 °C | at 25 °C | HSDB | |
| Decomposes (NTP, 1992) | decomposes | CAMEO |
2,4-D (ISO) vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 1.4e-7 mmHg | at 20 °C | HSDB |
| 0 mmHg | at 20 °C | CAMEO | |
| 0.4 mmHg | at 160 °C | NIOSH |
2,4-D (ISO) lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | Noncombustible Solid, but may be dissolved in flammable liquids. | NIOSH |
2,4-D (ISO) vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 7.63 (air = 1) | CAMEO |
2,4-D (ISO) odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | Detection: 3.13 mg/kg | HSDB |
2,4-D (ISO) corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | Forms water-soluble salts with alkali metals and amines | HSDB | |
| Most formulations are noncorrosive to spray equipment although some concentrates may be deleterious to painted surfaces. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
2,4-D (ISO) 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.
2,4-D (ISO) fire potential
Not combustible
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
2,4-D (ISO) storage and handling
2,4-D (ISO) safe storage
Store in an area without drain or sewer access. Separated from strong oxidants and food and feedstuffs.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
2,4-D (ISO) storage conditions
Conditions for safe storage, including any incompatibilities: Keep container tightly closed in a dry and well-ventilated place. Keep in a dry place. Light sensitive. Moisture sensitive.
Source: Hazardous Substances Data Bank (HSDB)
2,4-D (ISO) incompatible materials
Contact with strong oxidizers may cause fires or explosions.
Source: Hazardous Substances Data Bank (HSDB)
2,4-D (ISO) reactivity
2,4-DICHLOROPHENOXYACETIC ACID is incompatible with strong oxidizers. It is corrosive to metals. (NTP, 1992)
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check 2,4-D (ISO) in the storage compatibility matrix →
11 · Questions
2,4-D (ISO) — frequently asked questions
What is the CAS number of 2,4-D (ISO)?
The CAS number of 2,4-D (ISO) is 94-75-7. Its EC number is 202-361-1.
What does a 2,4-D (ISO) label have to show?
Under CLP Annex VI the label for 2,4-D (ISO) carries the pictograms Corrosion and Exclamation mark and the signal word is Danger.
Is 2,4-D (ISO) flammable?
CLP Annex VI assigns 2,4-D (ISO) 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 2,4-D (ISO) a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for 2,4-D (ISO). 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 2B: possibly carcinogenic to humans.
What is the exposure limit for 2,4-D (ISO)?
The US occupational exposure limit reported for 2,4-D (ISO) is 10.0 [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 2,4-D (ISO)?
The boiling point reported for 2,4-D (ISO) is 160 °C (320 °F), at 4 mmHg (reduced pressure) (HSDB).
What is the melting point of 2,4-D (ISO)?
The melting point reported for 2,4-D (ISO) is 138 °C (280.4 °F) (HSDB).
How should 2,4-D (ISO) be stored?
Conditions for safe storage, including any incompatibilities: Keep container tightly closed in a dry and well-ventilated place. Keep in a dry place. Light sensitive. Moisture sensitive. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to 2,4-D (ISO)
Keep going: substances starting with 0–9, or search the whole database by name, CAS number, pictogram or signal word.