Safety data sheet reference · CAS 1333-82-0
Chromium trioxide SDS
also: chromium trioxide MSDS · safety data sheet · CrO3 · CAS 1333-82-0 · EC 215-607-8 · chromic acid · hexavalent chromium
Official PDF from supplier
This page is a reference, not the legal document.
CAS number
1333-82-0
EC number
215-607-8
CLP Annex VI index
024-001-00-0
Molecular formula
CrO3
Molar mass
99.994 g/mol
§ 02 · Hazards identification
Chromium trioxide harmonised EU classification
CLP Annex VI · Index 024-001-00-0. A supplier SDS may add self-classified hazards — this is the legal minimum.
Precautionary statements
Codes ending in a colon introduce the action that follows — on a label they are printed as combined statements, such as P305+P351+P338.
§ 03 · Composition and identifiers
Chromium trioxide structure
Chromium trioxide is not a molecular compound. In the solid its atoms form an extended lattice, so CrO3 is a formula unit — the ratio of atoms — and not a molecule. There is no skeletal formula to draw.
Identifiers from PubChem (NIH, public domain).
§ 04 · First-aid measures
Chromium trioxide 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 CHROMIUM TRIOXIDE, ANHYDROUS. 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.
EYES
First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.
SKIN
IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.
INHALATION
IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.
INGESTION
Some heavy metals are VERY TOXIC POISONS, especially if their salts are very soluble in water (e.g., lead, chromium, mercury, bismuth, osmium, and arsenic). IMMEDIATELY call a hospital or poison control center and locate activated charcoal, egg whites, or milk in case the medical advisor recommends administering one of them. Also locate Ipecac syrup or a glass of salt water in case the medical advisor recommends inducing vomiting. Usually, this is NOT RECOMMENDED outside of a physician's care. If advice from a physician is not readily available and the victim is conscious and not convulsing, give the victim a glass of activated charcoal slurry in water or, if this is not available, a glass of milk, or beaten egg whites and IMMEDIATELY transport victim to a hospital. If the victim is convulsing or unconscious, do not give anything by mouth, assure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital.
OTHER
Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, its chemical, physical and toxicity properties, the exposure level, length of exposure, and the route of exposure.
Source: NTP, 1992 — via CAMEO Chemicals (NOAA), public domain.
§ 05 · Fire-fighting measures
Chromium trioxide fire fighting measures
ERG 2024 · GUIDE 141 Oxidizers - ToxicERG guidance is written per response guide, not per substance — Guide 141 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
Extinguishing media and tactics
SMALL FIREUse water. Do not use dry chemicals or foams. CO2 or Halon® may provide limited control.
LARGE FIREFlood fire area with water from a distance. Do not move cargo or vehicle if cargo has been exposed to heat. If it can be done safely, move undamaged containers away from the area around the fire.
FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY 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. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn.
Source: ERG, 2024 — via CAMEO Chemicals (NOAA), public domain. Entry: CHROMIUM TRIOXIDE, ANHYDROUS.
§ 06 · Accidental release measures
Chromium trioxide spill and leak response
Containment and clean-up
Keep combustibles (wood, paper, oil, etc.) away from spilled material. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk.
SMALL DRY SPILLWith clean shovel, place material into clean, dry container and cover loosely; move containers from spill area.
LARGE SPILLDike far ahead of spill for later disposal.
Initial isolation and evacuation
IMMEDIATE PRECAUTIONARY MEASUREIsolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.
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: CHROMIUM TRIOXIDE, ANHYDROUS.
§ 07 · Handling and storage
Chromium trioxide computed storage compatibility
Derived from CLP Annex VI classification and CAMEO reactive-group data — not copied from a PDF.
⚠ Strong Oxidizing Agent⚠ Water-Reactive
⛔ Never store with
↔ Keep separate
Full interactive verdict — reactions, gas release on contact, ADR forms →
§ 08 · Exposure controls
Chromium trioxide exposure limits (IDLH)
IDLH
Immediately Dangerous to Life or Health
15 mg Cr(VI)/m3
The limit is expressed as Cr(VI), not as the mass of chromium trioxide itself.
Carcinogen
NIOSH lists chromium trioxide as a potential occupational carcinogen — exposure should be kept as low as achievable regardless of the IDLH figure.
NIOSH Pocket Guide — Chromium trioxide →
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.
§ 09 · Physical and chemical properties
Chromium trioxide physical properties
Source: CAMEO Chemicals (NOAA, public domain); per-value source references stored in the database.
§ 10 · Stability and reactivity
Reactive group (CAMEO/NOAA): Anhydrides, Oxidizing Agents, Strong. Our database documents 83 incompatible and 22 caution reaction-partner groups for chromium trioxide — including which combinations release gas on contact. See the per-partner breakdown with gas release →
83
Incompatible
22
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
Chromium trioxide road transport — ADR 2025
UN number
Proper shipping name
CHROMIUM TRIOXIDE, ANHYDROUS
Class · PG
5.1 · II
Classification code
OTC
Transport category
2
ADR labels
5.1, 6.1, 8
Hazard ID (Kemler) / UN plate
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
Chromium trioxide 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 "chromium trioxide MSDS" and a "chromium trioxide SDS" refer to the same document — today it is issued as an SDS. Full breakdown of the differences →
Other oxidizers in our database
Substance profile
What chromium trioxide is
Physical and chemical properties with the conditions each value was measured under, synonyms, formula and the harmonised CLP classification →
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 chromium trioxide
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
- Emergency response (§4–§6): ERG 2024 (PHMSA) · NIOSH Pocket Guide (CDC) · CHRIS (USCG) · NTP · EPA — via CAMEO Chemicals (NOAA), all US federal public domain, reproduced verbatim
- 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 2026-08-11.
Frequently asked questions about chromium trioxide
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 "chromium trioxide MSDS" is today issued as an SDS.
What GHS pictograms does chromium trioxide require?
Under the harmonised EU classification (CLP Annex VI), chromium trioxide carries GHS03 and GHS05 and GHS06 and GHS08 and GHS09 with the signal word "Danger". Hazard statements: H271, H350, H340, H361f, H330, H311, H301, H372, H314, H334, H317, H400, H410. A supplier's SDS may add self-classified hazards on top of this harmonised minimum.
What should chromium trioxide never be stored with?
Based on its storage classes (Oxidizers, Acute toxics), chromium trioxide must not share storage with: Cyanides & sulfides; Flammable liquids; Flammable solids; Mineral acids; Organic acids; Organic peroxides & self-reactives; Reactive metals; Water-reactives. Verify against the supplier's SDS sections 7 and 10 before finalising storage.
Where can I download an official chromium trioxide 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.
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 CHROMIUM TRIOXIDE, ANHYDROUS — confirm it matches the form in front of you.
01 · First aid
What to do for the person
EYES
First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.
SKIN
IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.
INHALATION
IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.
INGESTION
Some heavy metals are VERY TOXIC POISONS, especially if their salts are very soluble in water (e.g., lead, chromium, mercury, bismuth, osmium, and arsenic). IMMEDIATELY call a hospital or poison control center and locate activated charcoal, egg whites, or milk in case the medical advisor recommends administering one of them. Also locate Ipecac syrup or a glass of salt water in case the medical advisor recommends inducing vomiting. Usually, this is NOT RECOMMENDED outside of a physician's care. If advice from a physician is not readily available and the victim is conscious and not convulsing, give the victim a glass of activated charcoal slurry in water or, if this is not available, a glass of milk, or beaten egg whites and IMMEDIATELY transport victim to a hospital. If the victim is convulsing or unconscious, do not give anything by mouth, assure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital.
OTHER
Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, its chemical, physical and toxicity properties, the exposure level, length of exposure, and the route of exposure.
02 · Fire
Extinguishing and tactics
Fire and explosion hazard
Behavior in Fire: Containers may explode
Extinguishing media and tactics
SMALL FIREUse water. Do not use dry chemicals or foams. CO2 or Halon® may provide limited control.
LARGE FIREFlood fire area with water from a distance. Do not move cargo or vehicle if cargo has been exposed to heat. If it can be done safely, move undamaged containers away from the area around the fire.
FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY 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. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn.
03 · Spill
Containment, isolation, evacuation
Containment and clean-up
Keep combustibles (wood, paper, oil, etc.) away from spilled material. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk.
SMALL DRY SPILLWith clean shovel, place material into clean, dry container and cover loosely; move containers from spill area.
LARGE SPILLDike far ahead of spill for later disposal.
Initial isolation and evacuation
IMMEDIATE PRECAUTIONARY MEASUREIsolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.
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.