Substance profile
Metaldehyde
Metaldehyde is a crystalline powder with a menthol odor.
01 · Identification
What Metaldehyde is
Metaldehyde is a crystalline powder with a menthol odor. Its molecular formula is C8H16O4 and its molecular weight is 176.21 g/mol. It boils at 115 °C, melts at 246 °C.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 3rd degree.
02 · Identifiers
Metaldehyde identifiers and molecular data
Metaldehyde CAS number and EC number
Metaldehyde molecular formula and molecular weight
Other names for Metaldehyde
- metaldehyde (ISO)
- 2,4,6,8-tetramethyl- 1,3,5,7-tetraoxacyclooctane
03 · GHS classification
Metaldehyde hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Metaldehyde pictograms and signal word
Metaldehyde hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable solids GHS chapter 2.7 | Category 1 or 2 | H228 | GHS02 |
| Acute toxicity - oral GHS chapter 3.1 | Category 3 | H301 | GHS06 |
| 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.
Metaldehyde hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H228 | Flammable solid. |
| H361f | Suspected of damaging fertility. |
| H301 | Toxic if swallowed. |
| H412 | Harmful to aquatic life with long lasting effects. |
This page lists only the codes assigned to Metaldehyde. 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 Metaldehyde
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 Metaldehyde 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
Metaldehyde precautionary statements
CLP Annex VI assigns 6 precautionary statements to Metaldehyde. 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
Metaldehyde 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 | металдехид (ISO) 2,4,6,8-тетраметил-1,3,5,7-тетраоксациклооктан |
| Spanish español | Metaldehído (ISO) 2,4,6,8-tetrametil-1,3,5,7-tetraoxaciclooctano |
| Czech čeština | metaldehyd (ISO) 2,4,6,8-tetramethyl-1,3,5,7-tetraoxacyklooktan |
| Danish dansk | metaldehyd (ISO) 2,4,6,8-tetramethyl-1,3,5,7-tetraoxacyclooctan |
| German Deutsch | Metaldehyd (ISO) 2,4,6,8-Tetramethyl-1,3,5,7-tetraoxacyclooctan |
| Estonian eesti | metaldehüüd (ISO) 2,4,6,8-tetrametüül-1,3,5,7-tetraoksatsüklooktaan |
| Greek ελληνικά | metaldehyde (μεταλδεΰδη) (ISO) 2,4,6,8-τετραμεθυλο-1,3,5,7-τετραοξακυκλοοκτάνιο |
| English English | metaldehyde (ISO) 2,4,6,8-tetramethyl-1,3,5,7-tetraoxacyclooctane |
| French français | métaldéhyde (ISO) 2,4,6,8-tétraméthyl-1,3,5,7-tétraoxacyclooctane |
| Croatian hrvatski | metaldehid (ISO) 2,4,6,8-tetrametil-1,3,5,7-tetraoksaciklooktan |
| Italian italiano | metaldeide (ISO) 2,4,6,8-tetrametil-1,3,5,7-tetraossacicloottano |
| Latvian latviešu | metaldehīds (ISO) 2,4,6,8-tetrametil-1,3,5,7-tetraoksaciklooktāns |
| Lithuanian lietuvių | metaldehidas (ISO) 2,4,6,8-tetrametil-1,3,5,7-tetraoksaciklooktanas |
| Hungarian magyar | metaldehid (ISO) 2,4,6,8-tetrametil-1,3,5,7-tetraoxaciklo-oktán |
| Maltese Malti | metaldeid (ISO) 2,4,6,8-tetrametil-1,3,5,7-tetraossaċikloottan |
| Dutch Nederlands | metaldehyde (ISO) 2,4,6,8-tetramethyl-1,3,5,7-tetraoxacycloöctaan |
| Polish polski | metaldehyd (ISO) 2,4,6,8-tetrametylo-1,3,5,7-tetraoksacyklooktan |
| Portuguese português | metaldeído (ISO) 2,4,6,8-tetrametil-1,3,5,7-tetraoxaciclo-octano |
| Romanian română | metaldehidă (ISO) 2,4,6,8-tetrametil-1,3,5,7-tetraoxaciclooctan |
| Slovak slovenčina | metaldehyd (ISO) 2,4,6,8-tetrametyl-1,3,5,7- tetraoxacyklooktán |
| Slovenian slovenščina | metaldehid (ISO) 2,4,6,8-tetrametil-1,3,5,7-tetraoksaciklooktan |
| Finnish suomi | Metaldehydi (ISO) 2,4,6,8-tetrametyyli-1,3,5,7-tetraoksasyklo-oktaani |
| Swedish svenska | metaldehyd (ISO) 2,4,6,8-tetrametyl-1,3,5,7-tetraoxacyklooktan |
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
Metaldehyde GHS label elements
Everything CLP Annex VI fixes for Metaldehyde, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Metaldehyde
- Flammable solid.
- Suspected of damaging fertility.
- Toxic if swallowed.
- Harmful 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.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Metaldehyde in the GHS label constructor →
07 · Health hazards
Metaldehyde health hazards and exposure limits
Metaldehyde hazard summary
Not irritating to skin and slightly irritating to eyes of rabbits; Neurological effects (ataxia, twitching, tremors, and hind-limb paralysis) observed in studies of dogs and rats; No increased susceptibility of fetuses seen in developmental toxicity and 2-generation reproduction studies of rats and rabbits; Atrophy of the testes and prostate observed in chronic oral study of dogs (LOAEL = 90 mg/kg/day); [Reference #1] Slowly hydrolyzed in acidic media (i.e., in the stomach) to acetaldehyde (the main toxicologically significant component) which is further oxidized to acetic acid; A skin, eye, and mucous membrane irritant; May be corrosive to eyes; Inhalation of fumes can cause CNS depression, convulsions, and coma; Interferes with reproductive process in rats; No evidence of teratogenicity, carcinogenicity, or mutagenicity; [Reference #2] Highly flammable; An irritant; Toxic by ingestion; [Alfa Aesar MSDS] See Polyacetaldehyde.
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
08 · Physical and chemical properties
Metaldehyde 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.
Metaldehyde boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 115 °C (239 °F) | sublimes, sublimes | HSDB |
Metaldehyde melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 246.2 °C (475.2 °F) | closed capillary | HSDB |
Metaldehyde density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.27 g/cm³ | at 20 °C | HSDB |
Metaldehyde solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Insoluble in water, acetone, acetic acid, and carbon disulfide. | HSDB | |
| In toluene 530 mg/L at 20 °C, in methanol 1730 mg/L at 20 °C | at 20 °C | HSDB |
Metaldehyde vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 49500000 mmHg | at 25 °C | HSDB |
| Vapor pressure is negligible at room temperature. | HSDB |
Metaldehyde flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 36.11 °C (97 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Metaldehyde 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.
Metaldehyde fire potential
Moderate when exposed to heat or flame; can react with oxidizing materials.
Source: Hazardous Substances Data Bank (HSDB)
Solubility
Moderately soluble in water, fairly soluble in toluene, readily soluble in methanol, very soluble in benzene and chloroform, insoluble in acetic acid, and slightly soluble in ethanol.
Source: HSDB
10 · Handling and storage
Metaldehyde storage and handling
Metaldehyde storage conditions
Regulated by IATA.
Source: Hazardous Substances Data Bank (HSDB)
Metaldehyde incompatible materials
Can react with oxidizing materials.
Source: Hazardous Substances Data Bank (HSDB)
Metaldehyde reactivity
METALDEHYDE is an ether derivative. The ether being relatively unreactive. Flammable and/or toxic gases are generated by the combination of alcohols with alkali metals, nitrides, and strong reducing agents. They react with oxoacids and carboxylic acids to form esters plus water. Oxidizing agents convert alcohols to aldehydes or ketones.
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Metaldehyde in the storage compatibility matrix →
11 · Transport
Metaldehyde 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.
Metaldehyde under UN 1332 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| METALDEHYDE | 4.1 | F1 | III | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 4.1 is “Flammable solids, self-reactive substances, polymerizing substances and solid desensitized explosives” (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) |
|---|---|---|---|
| Metaldehyde | 4.1 | III | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 4.1 is “Flammable solid” (49 CFR 173.2).
12 · Questions
Metaldehyde — frequently asked questions
What is the CAS number of Metaldehyde?
The CAS number of Metaldehyde is 108-62-3. Its EC number is 203-600-2.
What is the chemical formula of Metaldehyde?
The molecular formula of Metaldehyde is C8H16O4 and its molecular weight is 176.21 g/mol.
What does a Metaldehyde label have to show?
Under CLP Annex VI the label for Metaldehyde carries the pictograms Flame, Skull and crossbones and Health hazard and the signal word is Danger.
Is Metaldehyde flammable?
Yes. CLP Annex VI assigns Metaldehyde H228 — flammable solid. The flash point reported for it is 36.11 °C (97 °F) (HSDB).
Is Metaldehyde a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Metaldehyde. 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 boiling point of Metaldehyde?
The boiling point reported for Metaldehyde is 115 °C (239 °F), sublimes, sublimes (HSDB).
What is the melting point of Metaldehyde?
The melting point reported for Metaldehyde is 246.2 °C (475.2 °F), closed capillary (HSDB).
How should Metaldehyde be stored?
Regulated by IATA. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Metaldehyde
Keep going: substances starting with M, or search the whole database by name, CAS number, pictogram or signal word.