Ozone

1Identification

Name

Ozone

IUPAC name

ozone

CAS number

10028-15-6

EC number

233-069-2

Molecular formula

O3

Molecular weight

47.998 g/mol

InChIKey

CBENFWSGALASAD-UHFFFAOYSA-N

SMILES

[O-][O+]=O

PubChem CID

24823

Synonyms

OZONE, Triatomic oxygen, Ozon, Ozone heavy work, ozono, trioxygen, Oxygen, mol (O3), trioxygene, Low Level Ozone, Level Ozone, Low, Ozone, Low Level, Ozone, Tropospheric, Level Ozone, Ground, Ozone, Ground Level

Recommended uses

• Occupational exposure from welding fumes; Also used as a disinfectant in water treatment and as a bleaching agent in food, textile, and paper processing; [Levy, p. 409] . . . Gas metal arc and gas tungsten arc welding produce the highest ozone concentrations, especially when aluminum is used as a base metal. [Welding, Brazing and Thermal Cutting. NIOSH Criteria for a Recommended Standard. Publication No. 88-110:33,1988] TWA ozone concentrations exceeded the ACGIH TLV at a pulp and paper plant construction site. The source was the electrostatic precipitators on the operating boiler stacks located upwind from the construction site. [Appl Occup Environ Hyg. 1999 Apr;14(4):203-7]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Welding [Category: Weld] Metal Thermal Spraying [Category: Plate] Pulp and Paper Processing [Category: Industry] Textiles (Fiber & Fabric Manufacturing) [Category: Industry] Using Disinfectants or Biocides [Category: Clean] Sewer and Wastewater Treatment [Category: Industry]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Ceramics making [Category: Hobbies]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Oxidizing agent
  EPA Chemical Data Reporting (CDR)

Description

• Ozone appears as a colorless to bluish gas that condenses to a dark blue liquid, or blue-black crystals. Has a characteristic odor in concentrations less than 2 ppm. Used as a disinfectant for air and water; used for bleaching waxes, textiles and oils, ozonolysis of unsaturated fatty acids to pelargonic and other acids; manufacture of ink; catalyst; water treatment for taste and odor control; mold and bacteria inhibitor in cold storage; bleaching agent. (EPA, 1998)
  CAMEO Chemicals
• Ozone is an elemental molecule with formula O3. An explosive, pale blue gas (b.p. 112C) that has a characteristic, pungent odour, it is continuously produced in the upper atmosphere by the action of solar ultraviolet radiation on atmospheric oxygen. It is an antimicrobial agent used in the production of bottled water, as well as in the treatment of meat, poultry and other foodstuffs. It has a role as a mutagen, a tracer, an antiseptic drug, a disinfectant, an electrophilic reagent, an oxidising agent and a member of greenhouse gas. It is a gas molecular entity, an elemental molecule, a member of reactive oxygen species and a triatomic oxygen.
  ChEBI
• Ozone has been used in trials studying the treatment of Mild Asthma and Primary Apical Periodontite.
  DrugBank

2Hazard identification

Signal word

Danger

Pictograms

GHS03, GHS05, GHS06, GHS07, GHS08, GHS09

Classification source

European Chemicals Agency (ECHA)

Precautionary statements

Other reported classifications

3 classification records exist across sources. Differences usually reflect purity, physical form or impurities.

Health hazards

• Ozone is highly toxic via inhalation or by contact of liquid to skin, eyes, or mucous membranes. It is capable of causing acute to chronic lung damage, burns, and death or permanent injury. Ozone can be toxic at a concentration of 100 ppm for 1 minute. Ozone is capable of causing death from pulmonary edema. It increases sensitivity of the lungs to bronchoconstrictors and allergens, increases susceptibility to and severity of lung bacterial and viral infections. (EPA, 1998)
  CAMEO Chemicals

Fire hazards

• Severe explosion hazard when shocked, exposed to heat or flame, or by chemical reaction with organic substances, especially reducing agents. Ozone is a powerful oxidizing agent. Incompatible with alkenes; aromatic compounds; benzene, rubber; bromine; dicyanogen; diethyl ether; dinitrogen tetroxide; hydrogen bromide; 4-hydroxy-4-methyl-1,6-heptadiene; nitrogen trichloride; stibine; tetrafluorohydrazine. Avoid contact with organic materials. (EPA, 1998)
  CAMEO Chemicals
• Not combustible but enhances combustion of other substances. Many reactions may cause fire or explosion. Risk of fire and explosion on contact with combustible substances.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Hazards summary

• Like phosgene and nitrogen dioxide, ozone is classified as less soluble relative to more soluble irritant inhalants like ammonia and chlorine. The less soluble vapors are more likely to cause potentially fatal pulmonary edema without the signs of severe upper respiratory injury. (See Comments for phosgene.) [LaDou, p. 564] Ozone is fibrogenic to the lungs in the context of an acute inhalation exposure complicated by bronchiolitis obliterans.
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

3Composition / information on ingredients

This page describes the pure substance. Commercial products may be solutions or mixtures. Check Section 3 of your supplier's SDS for concentrations and other ingredients.

4First-aid measures

• Warning: Effects may be delayed for 12 to 24 hours. Caution is advised. Signs and Symptoms of Acute Ozone Exposure: Signs and symptoms of acute exposure to ozone may be severe and include irritation and burns of the skin, eyes, and mucous membranes. An increased respiratory rate, shallow breathing, cough, dyspnea (shortness of breath), bronchitis, pulmonary edema, and pulmonary hemorrhage may occur. Tachycardia (rapid heart rate) and hypotension (low blood pressure) may be observed. Neurologic effects include fatigue, dizziness, drowsiness, headache, exhiliration, and depression. Nausea, vomiting, and anorexia may occur. Eye exposure may result in conjuctivitis (red, inflamed eyes).
  CAMEO Chemicals
• (General first aid procedures) Eye: Medical attention - Self-explanatory Breathing: Fresh air; 100% O2
  The National Institute for Occupational Safety and Health (NIOSH)

Symptoms of exposure

• Sore throat. Cough. Headache. Shortness of breath. Laboured breathing.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• ON CONTACT WITH LIQUID: FROSTBITE.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Redness. Pain.
  ILO-WHO International Chemical Safety Cards (ICSCs)

5Fire-fighting measures

Not available in the public sources we compile. Check Section 5 of the supplier's SDS.

6Accidental release measures

Isolation and evacuation

• Excerpt from ERG Guide 123 [Gases - Toxic]: IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions. SPILL: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 1955 datasheet. FIRE: If 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. (ERG, 2024)
  CAMEO Chemicals

Spill cleanup

• Evacuate danger area! Consult an expert! Personal protection: chemical protection suit including self-contained breathing apparatus. Ventilation.
  ILO-WHO International Chemical Safety Cards (ICSCs)

7Handling and storage

• Fireproof if in building. Separated from all substances. Cool.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• CYLINDERS OF DISSOLVED OZONE SHOULD BE STORED IN REFRIGERATED AREAS & AWAY FROM ALL REDUCING AGENTS, FLAMMABLE MATERIALS & SUBSTANCES SUCH AS IRON, COPPER OR CHROMIUM THAT MAY CATALYZE DECOMP.
  Hazardous Substances Data Bank (HSDB)
• Store in well-ventilated, cool, dark places. Detached storage is preferred. Avoid storage near combustible materials.
  Hazardous Substances Data Bank (HSDB)

8Exposure controls / personal protection

Personal protective equipment

• Excerpt from NIOSH Pocket Guide for Ozone: Skin: No recommendation is made specifying the need for personal protective equipment for the body. Eyes: No recommendation is made specifying the need for eye protection. Wash skin: No recommendation is made specifying the need for washing the substance from the skin (either immediately or at the end of the work shift). Remove: No recommendation is made specifying the need for removing clothing that becomes wet or contaminated. Change: No recommendation is made specifying the need for the worker to change clothing after the workshift. (NIOSH, 2024)
  CAMEO Chemicals
• WORKERS HANDLING LIQ OZONE SHOULD WEAR PROTECTIVE EQUIPMENT DESIGNED FOR EXPOSURE TO CRYOGENIC LIQ, EG GLOVES MADE FROM PLASTICS OR ASBESTOS, EYE & FACE PROTECTION.
  Hazardous Substances Data Bank (HSDB)
• Recommendations for respirator selection. Max concn for use: 1 ppm. Respirator Class(es): Any chemical cartridge respirator with cartridge(s) providing protection against the compound of concern. Only nonoxidizable sorbents are allowed (not charcoal). Any supplied-air respirator.
  Hazardous Substances Data Bank (HSDB)
• Recommendations for respirator selection. Max concn for use: 2.5 ppm. Respirator Class(es): Any supplied-air respirator operated in a continuous flow mode. Any powered, air-purifying respirator with cartridge(s) providing protection against the compound of concern. Only nonoxidizable sorbents are allowed (not charcoal).
  Hazardous Substances Data Bank (HSDB)

Respirator recommendations

• NIOSH/OSHA Up to 1 ppm: (APF = 10) Any chemical cartridge respirator with cartridge(s) providing protection against the compound of concern (APF = 10) Any supplied-air respirator Up to 2.5 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode (APF = 25) Any powered, air-purifying respirator with cartridge(s) providing protection against the compound of concern Up to 5 ppm: (APF = 50) Any chemical cartridge respirator with a full facepiece and cartridge(s) providing protection against the compound of concern (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of…
  The National Institute for Occupational Safety and Health (NIOSH)

9Physical and chemical properties

10Stability and reactivity

Reactivity

• OZONE is a propellant; ignites upon contact with alcohols, amines, ammonia, beryllium alkyls, boranes, dicyanogen, hydrazines, hydrocarbons, hydrogen, nitroalkanes, powdered metals, silanes, or thiols [Bretherick 1979. p.174]. Aniline in a atmosphere of ozone produces a white galatinous explosive ozobenzene [Mellor 1:911. 1946-47]. A mixture of ether and ozone forms aldehyde and acetic acid and a heavy liquid, ethyl peroxide, an explosive [Mellor 1:911. 1946-47]. Severe explosions occur attempting to form tribromic octaoxide from bromine and ozone [Mellor 2, Supp. 1:748. 1956]. Mixtures of ozone and dinitrogen pentaoxide are flammable or explosive [Mellor 8, Supp. 2:276. 1967].
  CAMEO Chemicals
• No rapid reaction with air. No rapid reaction with water.
  CAMEO Chemicals

Incompatible materials and hazardous reactions

• All oxidizable materials (both organic and inorganic).
  Hazardous Substances Data Bank (HSDB)
• Explosive with alkenes, aromatic compounds, bromine, combustible gasses, diethyl ether, hydrogen bromide, isopropylidene compounds.
  Hazardous Substances Data Bank (HSDB)
• Dangerous /fire hazard/ by chemical reaction with aniline, benzene, bromide, (diallyl methyl carbinol + acetic acid), diethyl ether, nitrogen pentoxide, ethylene, hydrogen bromide, hydrogen iodide, nitrogen dioxide, nitric oxide, nitrogen chloride, NI3, nitroglycerin, organic liquids, organic matter, antimony.
  Hazardous Substances Data Bank (HSDB)

Chemical stability

• UNSTABLE GAS ... @ NORMAL TEMP DECOMP TO BIATOMIC OXYGEN. ... IN LIQ OR SOLID PHASE PARTICULARLY UNSTABLE.
  Hazardous Substances Data Bank (HSDB)

11Toxicological information

Target organs

• Eyes, respiratory system
  The National Institute for Occupational Safety and Health (NIOSH)

Short-term exposure effects

• The substance is irritating to the eyes and respiratory tract. The substance may cause effects on the central nervous system. This may result in impaired vigilance and performance. Inhalation of the gas may cause lung oedema. The effects may be delayed. The liquid may cause frostbite.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Long-term exposure effects

• Repeated or prolonged inhalation of the gas may cause effects on the lungs.
  ILO-WHO International Chemical Safety Cards (ICSCs)

12Ecological information

Not available in the public sources we compile. Check Section 12 of the supplier's SDS.

13Disposal considerations

• Evaporation: Provide ventilation to dilute and disperse small amt of ozone into the outside atmosphere.
  Hazardous Substances Data Bank (HSDB)
• In the fume hood, wastes to be slowly released to air.
  Hazardous Substances Data Bank (HSDB)

14Transport information

DOT label

• Poison Gas
  CAMEO Chemicals

Not available in the public sources we compile. Check Section 14 of the supplier's SDS.

How DOT hazard classes work →

15Regulatory information

• Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Ozone is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 100 lbs.
  Hazardous Substances Data Bank (HSDB)

Overview of SDS regulations (OSHA HazCom, WHMIS, REACH/CLP) →

16Other information

Compiled from PubChem CID 24823 and the sources it aggregates (attributed inline). Data retrieved 2026-10-12. This summary describes the pure substance and is not a supplier SDS.