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

Methylisothiazolinone

Methylisothiazolinone is colorless prisms.

CAS 2682-20-4 C4H5NOS 115.16 g/mol Danger

01 · Identification

What Methylisothiazolinone is

Methylisothiazolinone is colorless prisms. Its molecular formula is C4H5NOS and its molecular weight is 115.16 g/mol. It melts at 50.5 °C.

Under the GHS it carries the signal word Danger.

02 · Identifiers

Methylisothiazolinone identifiers and molecular data

Methylisothiazolinone CAS number and EC number

CAS number2682-20-4
EC number220-239-6
Index number (CLP Annex VI)613-326-00-9

Methylisothiazolinone molecular formula and molecular weight

Molecular formulaC4H5NOS
Molecular weight115.16 g/mol

Other names for Methylisothiazolinone

  • 2-methylisothiazol-3(2H)-one

03 · GHS classification

Methylisothiazolinone hazard classification

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

Methylisothiazolinone pictograms and signal word

Signal wordDanger

Methylisothiazolinone hazard class and category

GHS hazard classes Methylisothiazolinone falls into
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 1A or 1B or 1C H314 GHS05
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
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.

Methylisothiazolinone hazard statements (H-codes)

Hazard statements assigned to Methylisothiazolinone
CodeHazard statement
H330 Fatal if inhaled.
H311 Toxic in contact with skin.
H301 Toxic if swallowed.
H314 Causes severe skin burns and eye damage.
H318 Causes serious eye damage.
H317 May cause an allergic skin reaction.
H400 Very toxic to aquatic life.
H410 Very toxic to aquatic life with long lasting effects.

Methylisothiazolinone supplemental EU statements (EUH)

EU-specific statements assigned to Methylisothiazolinone. They exist only in CLP and have no counterpart in UN GHS.
CodeStatement
EUH071 Corrosive to the respiratory tract.

This page lists only the codes assigned to Methylisothiazolinone. 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 Methylisothiazolinone

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 Methylisothiazolinone 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

Methylisothiazolinone precautionary statements

CLP Annex VI assigns 20 precautionary statements to Methylisothiazolinone. 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.

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

Methylisothiazolinone 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-метилизотиазол-3(2 H )-он
Spanish español 2-Metilisotiazol-3(2 H )-ona
Czech čeština 2-methylisothiazol-3(2 H )-on
Danish dansk 2-methylisothiazol-3(2 H )-on
German Deutsch 2-Methyl-2 H -isothiazol-3-on
Estonian eesti 2-metüülisotiasool-3(2 H )-oon
Greek ελληνικά 2-μεθυλισοθειαζολ-3(2 H )-όνη
English English 2-methylisothiazol-3(2 H )-one
French français 2-méthylisothiazol-3(2 H )-one
Croatian hrvatski 2-metilizotiazol-3(2 H )-on
Italian italiano 2-metilisotiazol-3(2 H )-one
Latvian latviešu 2-metilizotiazol-3(2 H )-ons
Lithuanian lietuvių 2-metilizotiazol-3(2 H )-onas
Hungarian magyar 2-metilisotiazol-3(2 H )-on
Maltese Malti 2-metilisotiazol-3(2 H )-on
Dutch Nederlands 2-methylisothiazool-3(2 H )-on
Polish polski 2-metyloizotiazol-3(2 H )-on
Portuguese português 2-metilisotiazol-3(2H)-ona
Romanian română 2-metilizotiazol-3(2 H )-onă
Slovak slovenčina 2-metyl-2 H -izotiazol-3-ón
Slovenian slovenščina 2-metilizotiazol-3(2 H )-on
Finnish suomi 2-metyyli-isotiatsol-3(2 H )-oni
Swedish svenska 2-metylisotiazol-3(2 H )-on

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

Methylisothiazolinone GHS label elements

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

GHS05 Corrosion pictogramGHS06 Skull and crossbones pictogramGHS09 Environment pictogram

Danger

Methylisothiazolinone

  • Fatal if inhaled.
  • Toxic in contact with skin.
  • Toxic if swallowed.
  • Causes severe skin burns and eye damage.
  • Causes serious eye damage.
  • May cause an allergic skin reaction.
  • Very toxic to aquatic life.
  • Very toxic to aquatic life with long lasting effects.
  • Corrosive to the respiratory tract.
  • Do not breathe dust/fume/gas/mist/vapours/spray.
  • Avoid breathing dust/fume/gas/mist/vapours/spray.
  • Do not eat, drink or smoke when using this product.
  • Use only outdoors or in a well-ventilated area.
  • 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 ON SKIN:
  • IF INHALED:
  • IF IN EYES:
  • Immediately call a POISON CENTER/doctor/
  • Get medical advice/attention.
  • Rinse mouth.
  • Do NOT induce vomiting.
  • If skin irritation or rash occurs:
  • 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 Methylisothiazolinone in the GHS label constructor →

07 · Health hazards

Methylisothiazolinone health hazards and exposure limits

Methylisothiazolinone hazard summary

Allergic contact dermatitis reported in workers using products containing this preservative; [Kanerva, p. 1815] Danger of skin sensitization; [MAK] Cosmetic preservative that is a recognized contact allergen in consumers; [EC: SCCS - Opinion] Causes burns; Inhalation may cause corrosive injuries to upper respiratory tract and lungs; May cause skin sensitization; Harmful by ingestion; Toxic by inhalation; [Sigma-Aldrich MSDS] See ISOTHIAZOLINONES.

Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

08 · Physical and chemical properties

Methylisothiazolinone 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.

Methylisothiazolinone boiling point

Property Value Conditions Source
Boiling point 93 °C (199.4 °F) at 0.03 mmHg (reduced pressure) HSDB

Methylisothiazolinone melting point

Property Value Conditions Source
Melting point 50.5 °C (122.9 °F) range, midpoint shown HSDB

Methylisothiazolinone density

Property Value Conditions Source
Density 1.19 g/cm³ at 20 °C HSDB
1.35 g/cm³ at 25 °C HSDB

Methylisothiazolinone solubility

Property Value Conditions Source
Solubility Solubility in: acetonitrile 78.6; methanol 79.1; hexane 2.371; xylenol 15.65 (g/100 mL) HSDB

Methylisothiazolinone vapor pressure

Property Value Conditions Source
Vapor pressure 0.062 mmHg at 25 °C HSDB

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

09 · Handling and storage

Methylisothiazolinone storage and handling

Methylisothiazolinone storage conditions

Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage.

Source: Hazardous Substances Data Bank (HSDB)

Methylisothiazolinone incompatible materials

Materials to avoid: Strong oxidizing agents, Amines, Mercaptans, Reducing agents.

Source: Hazardous Substances Data Bank (HSDB)

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

10 · Questions

Methylisothiazolinone — frequently asked questions

What is the CAS number of Methylisothiazolinone?

The CAS number of Methylisothiazolinone is 2682-20-4. Its EC number is 220-239-6.

What is the chemical formula of Methylisothiazolinone?

The molecular formula of Methylisothiazolinone is C4H5NOS and its molecular weight is 115.16 g/mol.

What does a Methylisothiazolinone label have to show?

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

Is Methylisothiazolinone flammable?

CLP Annex VI assigns Methylisothiazolinone 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 Methylisothiazolinone a carcinogen?

CLP Annex VI records no harmonised carcinogenicity classification for Methylisothiazolinone. 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 Methylisothiazolinone?

The boiling point reported for Methylisothiazolinone is 93 °C (199.4 °F), at 0.03 mmHg (reduced pressure) (HSDB).

What is the melting point of Methylisothiazolinone?

The melting point reported for Methylisothiazolinone is 50.5 °C (122.9 °F), range, midpoint shown (HSDB).

How should Methylisothiazolinone be stored?

Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. (Hazardous Substances Data Bank (HSDB))

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