Hydrogen Peroxide

Classification

Hazards depend heavily on concentration, and suppliers classify the same strength differently. The profile below reflects industrial solutions of roughly 30–70%. Dilute consumer solutions are far less hazardous, while solutions above 60% are much more reactive. Oxidizing liquid, Category 2 (50% to under 70%) or Category 1 (70% and above); Acute toxicity (oral), Category 4; Skin corrosion, Category 1A; Serious eye damage, Category 1; STOT single exposure, Category 3 (respiratory irritation). Some suppliers classify 30% grades as causing serious eye damage only.

Hazard statements

• H271 May cause fire or explosion; strong oxidizer (70% and above).
• H272 May intensify fire; oxidizer (50% to under 70%).
• H302 Harmful if swallowed.
• H314 Causes severe skin burns and eye damage.
• H335 May cause respiratory irritation.

Key precautionary statements

• P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
• P220 Keep away from clothing and other combustible materials.
• P261 Avoid breathing mist or vapors.
• P280 Wear protective gloves, protective clothing, eye protection and face protection.
• P301+P330+P331 IF SWALLOWED: Rinse mouth. Do NOT induce vomiting.
• P303+P361+P353 IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water or shower.
• P305+P351+P338+P310 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. Immediately call a POISON CENTER or doctor.
• P403+P233 Store in a well-ventilated place. Keep container tightly closed (using a vented closure where the supplier specifies one).

OSHA, NIOSH and ACGIH all set 1 ppm (1.4 mg/m³) as an 8- or 10-hour TWA, and Cal/OSHA uses the same value. None of them sets a short-term limit. The NIOSH IDLH is 75 ppm. ACGIH lists hydrogen peroxide as A3 (confirmed animal carcinogen with unknown relevance to humans), and IARC places it in Group 3 (not classifiable). The New Jersey Department of Health notes that it causes genetic mutations and advises handling it with extreme caution. Vapor levels rise sharply with concentration and temperature, so heated or sprayed solutions need the most control. State OSHA plans may set different limits.

• Appearance: Colorless liquid, sold as a water solution in strengths from a few percent to above 70%
• Odor: Slightly sharp
• Molecular weight: 34.0
• Boiling point: 286°F (141°C) (NIOSH value; varies with concentration)
• Freezing point: 12°F (-11°C) (NIOSH value; varies with concentration)
• Flash point: Not applicable (noncombustible, but an oxidizer)
• Explosive limits: Not applicable
• Vapor pressure: 5 mmHg at 86°F (NIOSH value)
• Specific gravity: 1.39 (NIOSH value; lower for dilute solutions)
• Water solubility: Miscible
• Stability: Slowly breaks down into water and oxygen; heat, light, dirt and metal traces speed this up

Inhalation

Mist or vapor irritates the nose, throat and lungs, causing coughing and shortness of breath. High exposure can cause fluid buildup in the lungs (pulmonary edema), a medical emergency. Headache, dizziness, nausea and vomiting can also occur.

Skin

Brief contact with moderate strengths causes temporary whitening and stinging. Stronger solutions cause redness, blisters and chemical burns. NIOSH also lists hair bleaching.

Eyes

Can cause serious and permanent eye damage, including corneal ulcers, even at strengths that are only mildly irritating to skin.

Ingestion

Harmful if swallowed. Concentrated solutions burn the mouth and throat, and the oxygen released can cause dangerous swelling of the stomach. Get medical attention immediately.

Target organs

Eyes, skin, respiratory system

Long-term effects

Repeated exposure may cause bronchitis. It is a mutagen; IARC places it in Group 3 (not classifiable as to human cancer), and reproductive effects need further study.

Gloves

The New Jersey Department of Health lists nitrile, neoprene, natural rubber, Silver Shield/4H and Viton. See hand protection and confirm the material against the strength you use.

Eyes and face

Chemical splash goggles; add a face shield for strengths above about 30% or for transfers.

Respiratory

Use ventilation to keep vapor below 1 ppm. Air-purifying cartridges are not listed by NIOSH for routine use; NIOSH and NJDOH point to supplied-air respirators above the limit, with a pressure-demand SCBA above 75 ppm or for unknown concentrations. Use under a written respiratory protection program.

Clothing

Chemical-resistant apron, sleeves and boots; NJDOH lists Tychem QC, CPF 2, BR and Responder suits. Remove clothing promptly if splashed: peroxide-soaked cloth can ignite as it dries.

Store in the original vented containers in a cool, dark, well-ventilated area away from heat, sunlight and combustibles. Never return unused material to the original container, because contamination can trigger rapid decomposition. Sealed, unvented containers can build oxygen pressure and burst.

Keep the work area clean, use only compatible equipment (such as passivated aluminum, specific stainless steels or approved plastics) and dilute by adding peroxide to water. Concentrations above 60% need specialist handling procedures.

Keep away from

• Combustible and organic materials, including wood, paper, oils, solvents, alcohols, ketones such as acetone, aldehydes and ethers
• Metals and metal salts such as copper, brass, bronze, iron, zinc, silver, manganese and lead, and finely divided metals
• Strong bases such as sodium hydroxide and potassium hydroxide
• Sodium hypochlorite and other oxidizers such as perchlorates, permanganates and nitrates
• Ammonia, iodides, sulfites and reducing agents

• Evacuate unprotected people and remove combustible materials and ignition sources from the area.
• Wear goggles, face shield, chemical-resistant gloves and clothing; use supplied-air respiratory protection for large spills.
• Dilute small spills with large amounts of water. Do not soak up with sawdust, paper or other combustible absorbents.
• Contain larger spills with inert material such as sand, and collect into vented, compatible containers.
• Keep out of drains and confined spaces where oxygen can build up.
• For larger incidents, refer to ERG Guide 140 (8–60%, UN2984 and UN2014) or Guide 143 (above 60%, UN2015).

Suitable extinguishing media

• Flood with large amounts of water
• Water spray to cool fire-exposed containers
• Do not use dry chemical extinguishers (NJDOH)

Special hazards

Noncombustible, but a strong oxidizer that releases oxygen and can ignite wood, paper, oil and clothing. Heat and contamination speed decomposition, and containers may burst in a fire. Highly concentrated solutions can react explosively with organic materials. Firefighters should wear SCBA and full protective gear.

• OSHA Hazard Communication (29 CFR 1910.1200): Hazardous chemical; labels, safety data sheets and worker training required.
• OSHA Air Contaminants (29 CFR 1910.1000 Table Z-1): PEL 1 ppm TWA.
• CERCLA (40 CFR 302.4): Not a listed hazardous substance.
• EPCRA Section 302 (40 CFR 355): Solutions above 52% are an extremely hazardous substance, with a threshold planning quantity of 1,000 lb and a reportable quantity of 1,000 lb.
• EPCRA Section 313 / TRI (40 CFR 372.65): Not listed.
• DOT Hazardous Materials (49 CFR 172.101): Depends on strength. 8% to under 20%: UN2984, Class 5.1, PG III. 20–60%: UN2014, Class 5.1 with subsidiary Class 8, PG II. Above 60%: UN2015, Class 5.1 (8), PG I. Below 8% is not regulated for transport.

• NIOSH Pocket Guide: Hydrogen peroxide
• OSHA Occupational Chemical Database: Hydrogen peroxide
• NJ Department of Health Hazardous Substance Fact Sheet: Hydrogen peroxide
• Safety data sheet: Hydrogen peroxide solution (UN2014)
• Sigma-Aldrich SDS: Hydrogen peroxide solution 10–30%
• EPCRA Section 302 extremely hazardous substances list
• Evonik: Transport classification of hydrogen peroxide by concentration