Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Safety data sheet reference · CAS 124-38-9

Carbon dioxide SDS

also: carbon dioxide MSDS · safety data sheet · CO2 · CAS 124-38-9 · dry ice

Official PDF from supplier

This page is a reference, not the legal document.

CAS number

124-38-9

Molecular formula

CO2

No harmonised EU classification

Carbon dioxide has no entry in CLP Annex VI — there is no harmonised EU-wide classification for it. That is not evidence of safety. Suppliers remain obliged to self-classify it under CLP, and workplace hazards (dust, asphyxiation, thermal) can exist without a harmonised entry. Always obtain the supplier's SDS for the product you actually use.

Published emergency-response data does exist for carbon dioxide and is reproduced below — first aid, fire fighting and spill response come from US federal sources, not from a harmonised classification.

§ 03 · Composition and identifiers

Carbon dioxide molecular structure

Carbon dioxide is a molecular compound. The skeletal formula below is drawn from its PubChem SMILES string, and every value in this section is computed from that structure.

Skeletal formula of carbon dioxide (CO2)

2D skeletal formula · CO2

SMILES C(=O)=O
InChI InChI=1S/CO2/c2-1-3
InChIKey CURLTUGMZLYLDI-UHFFFAOYSA-N
PubChem CID 280 →

Hybridisation

C sp · O sp² ×2

Molecular geometry

linear · 180° ideal

Electron count

16 valence e⁻ · 4 lone pairs

Identifiers from PubChem (NIH, public domain). Structure diagram drawn with RDKit from the SMILES string. Geometry and hybridisation are computed from the connection table, not measured.

§ 04 · First-aid measures

Carbon dioxide first aid measures

Call your national emergency number first. These are published first-aid measures, not medical advice, and they do not replace emergency services, a poison control centre or the supplier's safety data sheet.

§4–§6 below reproduce the CAMEO Chemicals entry CARBON DIOXIDE. CAMEO publishes response data per product entry, so the entry can describe a solution, a refrigerated liquid or a molten form rather than the pure substance in §9 — check it matches what you are handling.

Eye: FROSTBITE - If eye tissue is frozen, seek medical attention immediately; if tissue is not frozen, immediately and thoroughly flush the eyes with large amounts of water for at least 15 minutes, occasionally lifting the lower and upper eyelids. If irritation, pain, swelling, lacrimation, or photophobia persist, get medical attention as soon as possible.

Skin: FROSTBITE - If frostbite has occurred, seek medical attention immediately; do NOT rub the affected areas or flush them with water. In order to prevent further tissue damage, do NOT attempt to remove frozen clothing from frostbitten areas. If frostbite has NOT occurred, immediately and thoroughly wash contaminated skin with soap and water.

Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.

Source: NIOSH, 2024 — via CAMEO Chemicals (NOAA), public domain.

§ 05 · Fire-fighting measures

Carbon dioxide fire fighting measures

ERG 2024 · GUIDE 120 Gases - Inert (Including Refrigerated Liquids)

ERG guidance is written per response guide, not per substance — Guide 120 covers every material assigned to it, so a few sentences reference other UN numbers in the same group.

Fire and explosion hazard

Behavior in Fire: Containers may explode when heated.

Extinguishing media and tactics

Use extinguishing agent suitable for type of surrounding fire. If it can be done safely, move undamaged containers away from the area around the fire. Damaged cylinders should be handled only by specialists.

FIRE INVOLVING TANKSFight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames.

Source: ERG, 2024 — via CAMEO Chemicals (NOAA), public domain. Entry: CARBON DIOXIDE.

§ 06 · Accidental release measures

Carbon dioxide spill and leak response

Containment and clean-up

Do not touch or walk through spilled material. Stop leak if you can do it without risk. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Allow substance to evaporate. Ventilate the area. CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning.

Initial isolation and evacuation

IMMEDIATE PRECAUTIONARY MEASUREIsolate spill or leak area for at least 100 meters (330 feet) in all directions.

LARGE SPILLConsider initial downwind evacuation for at least 100 meters (330 feet).

FIREIf tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.

Source: ERG, 2024 — via CAMEO Chemicals (NOAA), public domain. Entry: CARBON DIOXIDE.

§ 08 · Exposure controls

Carbon dioxide exposure limits (IDLH)

IDLH

Immediately Dangerous to Life or Health

40,000 ppm

NIOSH Pocket Guide — Carbon dioxide →

IDLH from the NIOSH Pocket Guide to Chemical Hazards (CDC, U.S. public domain), via CAMEO Chemicals. Occupational exposure limits — OSHA PEL, NIOSH REL and EU IOELV — are not published on this page yet.

MSDS vs SDS

Carbon dioxide 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 "carbon dioxide MSDS" and a "carbon dioxide SDS" refer to the same document — today it is issued as an SDS. Full breakdown of the differences →

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 carbon dioxide

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

§ 16 · Sources

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 2026-08-11.

Frequently asked questions about carbon dioxide

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 "carbon dioxide MSDS" is today issued as an SDS.

Where can I download an official carbon dioxide 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.

Emergency mode Carbon dioxide

Call emergency services first

112 in the EU · 911 in the US. This screen is published response information, not medical advice, and it does not replace emergency services, a poison centre or the supplier's safety data sheet.

Text below is the CAMEO Chemicals entry CARBON DIOXIDE — confirm it matches the form in front of you.

01 · First aid

What to do for the person

Eye: FROSTBITE - If eye tissue is frozen, seek medical attention immediately; if tissue is not frozen, immediately and thoroughly flush the eyes with large amounts of water for at least 15 minutes, occasionally lifting the lower and upper eyelids. If irritation, pain, swelling, lacrimation, or photophobia persist, get medical attention as soon as possible.

Skin: FROSTBITE - If frostbite has occurred, seek medical attention immediately; do NOT rub the affected areas or flush them with water. In order to prevent further tissue damage, do NOT attempt to remove frozen clothing from frostbitten areas. If frostbite has NOT occurred, immediately and thoroughly wash contaminated skin with soap and water.

Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.

02 · Fire

Extinguishing and tactics

Fire and explosion hazard

Behavior in Fire: Containers may explode when heated.

Extinguishing media and tactics

Use extinguishing agent suitable for type of surrounding fire. If it can be done safely, move undamaged containers away from the area around the fire. Damaged cylinders should be handled only by specialists.

FIRE INVOLVING TANKSFight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames.

03 · Spill

Containment, isolation, evacuation

Containment and clean-up

Do not touch or walk through spilled material. Stop leak if you can do it without risk. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Allow substance to evaporate. Ventilate the area. CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning.

Initial isolation and evacuation

IMMEDIATE PRECAUTIONARY MEASUREIsolate spill or leak area for at least 100 meters (330 feet) in all directions.

LARGE SPILLConsider initial downwind evacuation for at least 100 meters (330 feet).

FIREIf tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.

Sources: ERG 2024 (PHMSA) · NIOSH Pocket Guide (CDC) · CHRIS (USCG) · NTP · EPA — via CAMEO Chemicals (NOAA), public domain. Text reproduced verbatim.

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