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

1,1,1-Trichloroethane

1,1,1-Trichloroethane is a colorless liquid with a mild chloroform-like odor.

CAS 71-55-6 Warning

01 · Identification

What 1,1,1-Trichloroethane is

1,1,1-Trichloroethane is a colorless liquid with a mild chloroform-like odor. It boils at 74 °C, melts at -30 °C.

Under the GHS it carries the signal word Warning. It is classed as hazardous Air Pollutants (HAPs).

02 · Identifiers

1,1,1-Trichloroethane identifiers and molecular data

1,1,1-Trichloroethane CAS number and EC number

CAS number71-55-6
EC number200-756-3
Index number (CLP Annex VI)602-013-00-2

1,1,1-Trichloroethane molecular formula and molecular weight

Chemical class Hazardous Air Pollutants (HAPs)

Other names for 1,1,1-Trichloroethane

  • methyl chloroform

03 · GHS classification

1,1,1-Trichloroethane hazard classification

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

1,1,1-Trichloroethane pictograms and signal word

Signal wordWarning

1,1,1-Trichloroethane hazard class and category

GHS hazard classes 1,1,1-Trichloroethane falls into
Hazard class Category From code Pictogram
Acute toxicity - inhalation GHS chapter 3.1 Category 4 H332 GHS07
Hazardous to the ozone layer GHS chapter 4.2 Category 1 H420 GHS07

1,1,1-Trichloroethane hazard statements (H-codes)

Hazard statements assigned to 1,1,1-Trichloroethane
CodeHazard statement
H332 Harmful if inhaled.
H420 Harms public health and the environment by destroying ozone in the upper atmosphere

This page lists only the codes assigned to 1,1,1-Trichloroethane. 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 1,1,1-Trichloroethane

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 1,1,1-Trichloroethane 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

1,1,1-Trichloroethane precautionary statements

CLP Annex VI assigns 4 precautionary statements to 1,1,1-Trichloroethane. 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.

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

1,1,1-Trichloroethane 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 1,1,1-трихлороетан метилхлороформ
Spanish español 1,1,1-Tricloroetano metilcloroformo
Czech čeština 1,1,1-trichlorethan methylchloroform
Danish dansk 1,1,1-trichlorethan methylchloroform
German Deutsch 1,1,1-Trichlorethan Methylchloroform
Estonian eesti 1,1,1-trikloroetaan metüülkloroform
Greek ελληνικά 1,1,1-τριχλωροαιθάνιο μεθυλοχλωροφόρμιο
English English 1,1,1-trichloroethane methyl chloroform
French français 1,1,1-trichloroéthane méthylchloroforme
Croatian hrvatski 1,1,1-trikloretan metil-kloroform
Italian italiano 1,1,1-tricloroetano metilcloroformio
Latvian latviešu 1,1,1-trihloretāns metilhloroforms
Lithuanian lietuvių 1,1,1-trichloretanas metilchloroformas
Hungarian magyar 1,1,1-triklór-etán metil-kloroform
Maltese Malti 1,1,1-triklorotanu kloroform tal-metil
Dutch Nederlands 1,1,1-trichloorethaan methylchloroform
Polish polski 1,1,1-trichloroetan metylochloroform
Portuguese português 1,1,1-tricloroetano metilclorofórmio
Romanian română 1,1,1-tricloroetan metilcloroform
Slovak slovenčina 1,1,1-trichlóretán metylchloroform
Slovenian slovenščina 1,1,1-trikloroetan metil kloroform
Finnish suomi 1,1,1-trikloorietaani metyylikloroformi
Swedish svenska 1,1,1-trikloretan metylkloroform

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

1,1,1-Trichloroethane GHS label elements

Everything CLP Annex VI fixes for 1,1,1-Trichloroethane, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.

GHS07 Exclamation mark pictogram

Warning

1,1,1-Trichloroethane

  • Harmful if inhaled.
  • Harms public health and the environment by destroying ozone in the upper atmosphere
  • Do not breathe dust/fume/gas/mist/vapours/spray.
  • Use only outdoors or in a well-ventilated area.
  • IF INHALED:
  • Call a POISON CENTER/doctor/ if you feel unwell.

Supplier name, address and telephone number· Product identifier·Nominal quantity

Need this as an actual label? Open 1,1,1-Trichloroethane in the GHS label constructor →

07 · Health hazards

1,1,1-Trichloroethane health hazards and exposure limits

1,1,1-Trichloroethane hazard summary

1,1,1-Trichloroethane is a synthetic chemical that does not occur naturally in the environment. It also is known as methylchloroform, methyltrichloromethane, trichloromethylmethane, and trichloromethane. Its registered trade names are chloroethene NU® and Aerothene TT®.</p No 1,1,1-trichloroethane is supposed to be manufactured for domestic use in the United States after January 1, 2002 because it affects the ozone layer. 1,1,1-Trichloroethane had many industrial and household uses, including use as a solvent to dissolve other substances, such as glues and paints; to remove oil or grease from manufactured metal parts; and as an ingredient of household products such as spot cleaners, glues, and aerosol sprays.

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

1,1,1-Trichloroethane carcinogenicity classification

IARC classification Group 2A — Probably carcinogenic to humans
IARC monographs Volume 20: (1979) Some Halogenated Hydrocarbons; Volume 71: (1999) Re-evaluation of Some Organic Chemicals, Hydrazine and Hydrogen Peroxide (Part 1, Part 2, Part 3)

Studied by the US National Toxicology Program: TR-003: Bioassay of 1,1,1-Trichloroethane for Possible Carcinogenicity (CASRN 71-55-6) (1977 )

Cancer Classification: Group D Not Classifiable as to Human Carcinogenicity

Source: Hazardous Substances Data Bank (HSDB)

Evaluation: There is inadequate evidence for the carcinogenicity of 1,1,1-trichloroethane in humans. There is inadequate evidence for the carcinogenicity of 1,1,1-trichloroethane in experimental animals. Overall evaluation: 1,1,1-Trichloroethane is not classifiable as to its carcinogenicity to humans (Group 3).

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.

1,1,1-Trichloroethane occupational exposure limits

US occupational exposure limits reported for 1,1,1-Trichloroethane. PEL is enforceable (OSHA), REL is a recommendation (NIOSH), IDLH is the concentration at which escape becomes impossible without injury.
Limit Value Source
PEL 350.0 [ppm] Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
PEL 350 ppm (1900 mg/m³) Occupational Safety and Health Administration (OSHA)
PEL TWA 350 ppm (1900 mg/m3) See Appendix G The National Institute for Occupational Safety and Health (NIOSH)
REL 350 ppm (1900 mg/m³) [15 minutes] Occupational Safety and Health Administration (OSHA)
REL C 350 ppm (1900 mg/m3) [15-minute] See Appendix C (Chloroethanes) The National Institute for Occupational Safety and Health (NIOSH)
IDLH 700 ppm (NIOSH, 2024) CAMEO Chemicals
IDLH 700.0 [ppm] Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
IDLH 700 ppm 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

1,1,1-Trichloroethane 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.

1,1,1-Trichloroethane boiling point

Property Value Conditions Source
Boiling point 74 °C (165.2 °F) HSDB
73.89 °C (165 °F) NIOSH
74.11 °C (165.4 °F) at 760 mmHg CAMEO

1,1,1-Trichloroethane melting point

Property Value Conditions Source
Melting point -30 °C (-22 °F) HSDB
-30.56 °C (-23 °F) NIOSH
-32.5 °C (-26.5 °F) CAMEO

1,1,1-Trichloroethane density

Property Value Conditions Source
Density 1.34 g/cm³ NIOSH
1.3376 g/cm³ at 20 °C HSDB
1.31 g/cm³ at 20 °C CAMEO

1,1,1-Trichloroethane solubility

Property Value Conditions Source
Solubility Soluble in acetone, benzene, methanol, carbon tetrachloride and ether HSDB
Soluble in all common organic solvents and is a very good solvent for fats, paraffins, and other organic compounds. HSDB
In water, 1,290 mg/L at 25 °C at 25 °C HSDB

1,1,1-Trichloroethane vapor pressure

Property Value Conditions Source
Vapor pressure 100 mmHg NIOSH
100 mmHg at 20 °C CAMEO
124 mmHg at 25 °C HSDB

1,1,1-Trichloroethane flash point

Property Value Conditions Source
Flash point 93.33 °C (200 °F) above this value CAMEO
Flash point = none HSDB

1,1,1-Trichloroethane autoignition temperature

Property Value Conditions Source
Autoignition temperature 500 °C (932 °F) closed cup HSDB
500 °C (932 °F) CAMEO
537 °C (998.6 °F) ICSC

1,1,1-Trichloroethane lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) 7.5 % by volume HSDB

1,1,1-Trichloroethane upper explosive limit (UEL)

Property Value Conditions Source
Upper explosive limit (UEL) 12.5 % by volume HSDB

1,1,1-Trichloroethane vapor density

Property Value Conditions Source
Vapor density 4.63 (air = 1) HSDB
4.6 (air = 1) CAMEO

1,1,1-Trichloroethane odor threshold

Property Value Conditions Source
Odor threshold It has an odor similar to chloroform. HSDB
Odor Threshold Low: 16.0 [ppm] Haz-Map

1,1,1-Trichloroethane critical temperature and pressure

Property Value Conditions Source
Critical temperature and pressure 311.85 °C (593.3 °F) HSDB

1,1,1-Trichloroethane corrosivity

Property Value Conditions Source
Corrosivity Readily corrodes aluminum and aluminum alloys HSDB
Extremely corrosive to aluminum. Dry 1,1,1-trichloroethane moderately corrodes iron and zinc. HSDB

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

09 · Fire and explosion

1,1,1-Trichloroethane 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.

1,1,1-Trichloroethane fire potential

It burns only in excess of oxygen or in air if a strong source of ignition is present.

Source: Hazardous Substances Data Bank (HSDB)

Corrosivity

Dry, uninhibited 1,1,1-trichloroethane is not very corrosive with iron or zinc; corrosion rate with iron is < 2.54 micrometers/yr and with zinc < 25.4 micrometers/yr. Addition of 7% water increases corrosion rates to 254 micrometers/yr for iron and > 254 micrometers/yr for zinc. The presence of both water and ethanol increases iron or tin attack at reflux.

Source: HSDB

Odor

The odor may be noticeable at concentrations near 100 ppm, well below those known to cause physiological response. However, the odor at 500 ppm and even 1000 ppm is not so unpleasant as to discourage exposure. The odor has been described as strong and unpleasant at 1500-2000 ppm. It has been reported that female test subjects exposed to 350 ppm objected to the odor; however, this has not been an industrial problem.

Source: HSDB

10 · Handling and storage

1,1,1-Trichloroethane storage and handling

1,1,1-Trichloroethane safe storage

Separated from food and feedstuffs, strong oxidants, aluminium, magnesium and zinc. Cool. Dry. Store in an area without drain or sewer access.

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

1,1,1-Trichloroethane storage conditions

Storage temp: Ambient; Venting: Pressure-vacuum.

Source: Hazardous Substances Data Bank (HSDB)

1,1,1-Trichloroethane incompatible materials

Reacts slowly with water, releasing corrosive hydrochloric acid.

Source: Hazardous Substances Data Bank (HSDB)

Planning storage for a mix of chemicals? Check 1,1,1-Trichloroethane in the storage compatibility matrix →

11 · Questions

1,1,1-Trichloroethane — frequently asked questions

What is the CAS number of 1,1,1-Trichloroethane?

The CAS number of 1,1,1-Trichloroethane is 71-55-6. Its EC number is 200-756-3.

What does a 1,1,1-Trichloroethane label have to show?

Under CLP Annex VI the label for 1,1,1-Trichloroethane carries the pictogram Exclamation mark and the signal word is Warning.

Is 1,1,1-Trichloroethane flammable?

CLP Annex VI assigns 1,1,1-Trichloroethane 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 93.33 °C (200 °F), above this value (CAMEO).

Is 1,1,1-Trichloroethane a carcinogen?

CLP Annex VI records no harmonised carcinogenicity classification for 1,1,1-Trichloroethane. 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 2A: probably carcinogenic to humans.

What is the exposure limit for 1,1,1-Trichloroethane?

The US occupational exposure limit reported for 1,1,1-Trichloroethane is 350.0 [ppm] (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 1,1,1-Trichloroethane?

The boiling point reported for 1,1,1-Trichloroethane is 74 °C (165.2 °F) (HSDB).

What is the melting point of 1,1,1-Trichloroethane?

The melting point reported for 1,1,1-Trichloroethane is -30 °C (-22 °F) (HSDB).

How should 1,1,1-Trichloroethane be stored?

Storage temp: Ambient; Venting: Pressure-vacuum. (Hazardous Substances Data Bank (HSDB))

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