Safety data sheet reference · CAS 75-21-8

Ethylene oxide SDS

also: ethylene oxide MSDS · safety data sheet · CAS 75-21-8 · EC 200-849-9 · EtO · EO · oxirane

Danger · Flam. Gas 1 Carc. 1 · Muta. 1 · Category 3 · +5

Flame GHS02 Corrosion GHS05 Skull and Crossbones GHS06 Health Hazard GHS08

Official PDF from supplier

Sigma-Aldrich ↗ Fisher Scientific ↗ Carl Roth ↗

This page is a reference, not the legal document.

CAS number

75-21-8

EC number

200-849-9

CLP Annex VI index

603-023-00-X

Molecular formula

C2H4O

Molar mass

44.05 g/mol

§ 02 · Hazards identification

Harmonised EU classification

CLP Annex VI · Index 603-023-00-X. A supplier SDS may add self-classified hazards — this is the legal minimum.

H220 Extremely flammable gas. Flammable gas — Category 1 (Flam. Gas 1)

H301 Toxic if swallowed. Acute toxicity, oral — Category 3 (Acute Tox. 3)

H314 Causes severe skin burns and eye damage. Skin corrosion — Category 1 (Skin Corr. 1)

H318 Causes serious eye damage. Serious eye damage — Category 1 (Eye Dam. 1)

H331 Toxic if inhaled. Acute toxicity, inhalation — Category 3

H335 May cause respiratory irritation. Respiratory irritation — STOT SE 3

H336 May cause drowsiness or dizziness. Narcotic effects — STOT SE 3

H340 May cause genetic defects. Germ cell mutagenicity — Category 1 (Muta. 1)

H350 May cause cancer. Carcinogenicity — Category 1 (Carc. 1)

H372 Causes damage to organs through prolonged or repeated exposure. STOT repeated exposure — Category 1 (STOT RE 1)

Precautionary statements

P201 Obtain special instructions before use.

P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.

P233 Keep container tightly closed.

P260 Do not breathe dust/fume/gas/mist/vapours/spray.

P270 Do not eat, drink or smoke when using this product.

P271 Use only outdoors or in a well-ventilated area.

P280 Wear protective gloves/protective clothing/eye protection/face protection.

P301 IF SWALLOWED: call a POISON CENTER or doctor if you feel unwell.

P304 IF INHALED: remove person to fresh air and keep comfortable for breathing.

P305 IF IN EYES: rinse cautiously with water for several minutes.

P308 IF exposed or concerned: get medical advice/attention.

P310 Immediately call a POISON CENTER or doctor.

P313 Get medical advice/attention.

P314 Get medical advice/attention if you feel unwell.

P330 Rinse mouth.

P331 Do NOT induce vomiting.

P338 Remove contact lenses, if present and easy to do. Continue rinsing.

P403 Store in a well-ventilated place.

§ 07 · Handling and storage

Computed storage verdict

Keep separate from 13 storage groups Compressed gases Acute toxics

Derived from CLP Annex VI classification and CAMEO reactive-group data — not copied from a PDF.

⚠ Explosive⚠ Highly Flammable⚠ Polymerizable

↔ Keep separate

Bases Cyanides & sulfides Flammable liquids Flammable solids Compressed gases Mineral acids Organic acids Organic peroxides & self-reactives Oxidizing acids Oxidizers Reactive metals Acute toxics Water-reactives

Full interactive verdict — reactions, gas release on contact, ADR forms →

§ 09 · Physical and chemical properties

Measured properties

Fire-relevant values first — flash point and explosion limits decide the storage and ventilation regime.

Explosion limits

3 – 100 %

LEL / UEL in air, vol.

Autoignition

428.9 °C

Melting point -112.5 °C

Boiling point 10.7 °C

Relative density (water = 1) 0.8222

Source: CAMEO Chemicals (NOAA, public domain); per-value source references stored in the database.

§ 10 · Stability and reactivity

Reactive group (CAMEO/NOAA): Epoxides, Fluorinated Organic Compounds, Polymerizable Compounds. Our database documents 64 incompatible and 58 caution reaction-partner groups for ethylene oxide — including which combinations release gas on contact. See the per-partner breakdown with gas release →

Incompatible

Caution

§ 13 · Disposal considerations

Dispose of waste and residues in accordance with local and national regulations — in the EU under the Waste Framework Directive 2008/98/EC. Never discharge to drains or municipal waste; hand contaminated packaging and unused product to an authorised waste-disposal company. The supplier's SDS section 13 lists the applicable waste codes for the specific product.

§ 14 · Transport information

Road transport — ADR 2025

UN number

UN 1040

Proper shipping name

ETHYLENE OXIDE

Class · PG

Classification code

2TF

Transport category

ADR labels

2.3, 2.1

Hazard ID (Kemler) / UN plate

263

1040

Top: hazard identification number (Kemler). Bottom: UN number — as carried on the orange plate of the transport unit.

UN number

UN 1040

Proper shipping name

ETHYLENE OXIDE WITH NITROGEN up to a total pressure of 1 MPa (10 bar) at 50 °C

Class · PG

Classification code

2TF

Transport category

ADR labels

2.3, 2.1

Hazard ID (Kemler) / UN plate

263

1040

Top: hazard identification number (Kemler). Bottom: UN number — as carried on the orange plate of the transport unit.

Source: UN ADR 2025 (ECE/TRANS/352), Table A. Road (ADR) only — for sea (IMDG) and air (IATA), consult the supplier's SDS §14.

MSDS vs SDS

MSDS vs SDS: is there a difference?

MSDS (Material Safety Data Sheet) is the older name for the same document. In the US, OSHA's Hazard Communication Standard (2012) adopted the GHS-standardised 16-section Safety Data Sheet; in the EU the format is set by REACH Annex II. So a "ethylene oxide MSDS" and a "ethylene oxide SDS" refer to the same document — today it is issued as an SDS. Full breakdown of the differences →

Other compressed gases in our database

Compliance hub

From classification to SDS

The classification above corresponds to Section 2 of a Safety Data Sheet. Learn how a compliant 16-section SDS is structured and authored →

GHS label maker

Build the label for ethylene oxide

Pictograms, signal word and H-statements combined into a compliant label layout →

§ 16 · Sources

Classification: Regulation (EC) No 1272/2008 (CLP), Annex VI
Transport: UN ADR 2025 (UNECE), Table A
Reactivity: NOAA CAMEO Chemicals reactive-group matrix (public domain)
Physical properties: CAMEO Chemicals (NOAA, public domain) — per-value source references stored in the database
Substance data: PubChem · ECHA

Reference aid only. This page summarises the harmonised EU classification and computed storage guidance — it is not a Safety Data Sheet and does not replace one. Always verify hazards, handling and storage against the supplier's SDS (sections 7 and 10) and local regulations before use. Page updated 2026-07-27.

Frequently asked questions

Is an MSDS the same as an SDS?

In practice, yes. MSDS (Material Safety Data Sheet) is the older name for the same document. In the US, OSHA's Hazard Communication Standard (2012) adopted the GHS-standardised 16-section Safety Data Sheet; in the EU the SDS format is set by REACH Annex II. A document you find labelled "ethylene oxide MSDS" is today issued as an SDS.

What GHS pictograms does ethylene oxide require?

Under the harmonised EU classification (CLP Annex VI), ethylene oxide carries GHS02 and GHS05 and GHS06 and GHS08 with the signal word "Danger". Hazard statements: H220, H350, H340, H360Fd, H331, H301, H335, H336, H372, H314, H318. A supplier's SDS may add self-classified hazards on top of this harmonised minimum.

Where can I download an official ethylene oxide SDS PDF?

From your own supplier — an SDS is issued per product and supplier, so the correct PDF for an inspection is the one matching the product you actually purchased. The supplier links on this page lead to the official SDS libraries of major distributors.