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CHEMINFO Record Number: 198
CCOHS Chemical Name: Hydrogen peroxide solutions 35% and greater

Dihydrogen dioxide
Hydrogen dioxide
Hydrogen peroxide

Chemical Name French: Peroxyde d'hydrogène
Chemical Name Spanish: Peróxido de hidrógeno

Trade Name(s):

CAS Registry Number: 7722-84-1
UN/NA Number(s): 2014 2015
RTECS Number(s): MX0899500 MX0900000
EU EINECS/ELINCS Number: 231-765-0
Chemical Family: Inorganic peroxide / hydrogen oxide / hydrogen peroxide
Molecular Formula: H2-O2
Structural Formula: H-O-O-H


Appearance and Odour:
Clear, colourless liquid with a slightly sharp and irritating odour.(19)

Odour Threshold:
No information available.

Warning Properties:
NOT RELIABLE - information not available for evaluation.

All information given is for hydrogen peroxide solutions in water because this is the only form in which hydrogen peroxide is commercially available. Hydrogen peroxide is available in grades ranging from 3 to 90 wt.%. The most common grades for industrial applications or laboratory use are 35, 50 and 70 wt.%. Less concentrated solutions, such as 3-6%, are obtained by dilution of more concentrated ones, such as 35%, with water, usually with the addition of extra stabilizer.(4,20) Commercial solutions almost always contain very small amounts of impurities, such as iron or copper, which can cause decomposition. Therefore, stabilizers are often added to prevent decomposition into oxygen and water. Common stabilizers include sodium pyrophosphate, sodium stannate trihydrate, phosphoric or other mineral acids, alkali metal silicates, combinations of tin salts and phosphates, and organic stabilizers such as 8-hydroxyquinoline, pyridine carboxylic acids, tartaric and benzoic acids, acetanilide and acetophenetidin.(4,20,21)

Uses and Occurrences:
Hydrogen peroxide is mainly used for wood pulp bleaching. It is also used in the manufacture of a wide range of organic and inorganic chemicals, plastics and pharmaceuticals; for bleaching textiles, food, wood, linoleum, paper and other materials; to improve the colour of oils and waxes; in environmental applications, such as treatment of wastewaters and sewage, industrial and domestic effluents and treatment of cyanide-containing wastes; removal of toxic or malodorous pollutants from industrial gas streams and detoxifying organic pollutants; as a component of rocket propellant; as a disinfectant and antimycotic. It is used together with sulfuric acid for the pickling and chemical polishing of metal surfaces (such as copper and its alloys), and other metal surface treatments; etching and cleaning printed circuit boards; in mining (gold ore and uranium leaching); in food applications; and as an oxygen source in respiratory protective equipment.(4,20,21)


Clear, colourless liquid with a slightly sharp and irritating odour. Will not burn. STRONG OXIDIZER. Contact with combustible materials may cause fire or explosion. DANGEROUSLY REACTIVE. High temperatures or shock can cause violent decomposition. Can react violently or explosively with many chemicals. May form explosive peroxides. TOXIC. May be fatal if swallowed. CORROSIVE to the eyes and skin. Corrosive to steel, iron, nickel, copper and its alloys.

Important New Information:
NOTE: The evaluation of this chemical as toxic is under review. For additional information, contact the CHEMINFO team at


Effects of Short-Term (Acute) Exposure

Hydrogen peroxide does not readily form a vapour at room temperature. If heated or misted, it is irritating to the nose, throat and respiratory tract, based on limited human and animal information. In very severe cases, bronchitis or a potentially life-threatening accumulation of fluid in the lungs (pulmonary edema) may occur. However, no reports of these effects in humans were located.
Throat irritation has been reported in employees exposed to aerosol concentrations of 12 to 41 mg/m3.(1) No effect on airways resistance was observed in volunteers exposed to 0.3 mg/m3 of hydrogen peroxide aerosol for 5 minutes.(2) In volunteers exposed to the aerosol for 4 hours, the threshold for respiratory tract irritation was 10 mg/m3.(3)

Skin Contact:
Hydrogen peroxide solutions of 35% are very mild skin irritants while solutions of 50% and 70% are severely irritating and corrosive respectively, based on animal information. Corrosive materials are capable of producing severe burns, blisters, ulcers and permanent scarring, depending on the concentration of the solution and the duration of contact. Whitening or bleaching of the skin has been observed in humans following contact with dilute solutions.(4,5,6) A man accidentally spilled 35% hydrogen peroxide on his back and shoulder resulting in redness and an eruption of gas bubbles under the skin described as being similar to bubble wrap. The skin eruptions healed rapidly without scarring following treatment.(35)

Eye Contact:
Hydrogen peroxide solutions of 35% and greater are corrosive to eyes based on animal information. Corrosive materials are capable of producing severe eye burns, and permanent injury, including blindness, depending on the concentration of the solutions and duration of contact. No human information was located for hydrogen peroxide solutions of 35% and greater. Direct contact with dilute solutions (up to 3%) has not resulted in permanent eye injury.(7)

Case reports of non-occupational ingestion of hydrogen peroxide describe symptoms such as sharp pains in the abdomen, foaming at the mouth, vomiting, temporary unconsciousness and fever. Sensory and motor impairment have also been described. Concentrated solutions (greater than 35%) irritate the gastrointestinal tract and may cause corrosive injury and death. Hydrogen peroxide reacts in the stomach releasing large amounts of oxygen.(4,5) Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

INHALATION EXPOSURE: No firm conclusions can be drawn from one case report. This report described reversible lung disease in an employee exposed to 12 to 41 mg/m3 of hydrogen peroxide aerosols for 1 year. This individual was also a heavy smoker which may have contributed to him developing lung disease. Six other employees similarly exposed did not show evidence of lung disease. All 7 employees reported eye and throat irritation and gradual bleaching of their hair since the machine which generated hydrogen peroxide was in use.(1)

SKIN SENSITIZATION: There is one occupational case report of a hairdresser who developed an intensely itchy rash. She later tested positive to a 3% solution of hydrogen peroxide, as well as nickel sulfate and 4-aminophenol. She had no previous history of allergies. This authors indicate that 156 other hairdressers tested negative to 3% hydrogen peroxide.(8) Negative results were also reported for hydrogen peroxide in another study of employees exposed to several chemicals in a hydrogen peroxide production unit.(9)


In a limited human population study, there was no indication of an increased risk of cancer due to hydrogen peroxide exposure. This study is limited by the small number of people studied and possibly low exposure levels.(34) Animal studies have shown that long-term oral administration of 0.1-0.15% hydrogen peroxide causes an inflammatory response in the gastro-duodenal tissue of mice. This inflammatory response may progress to carcinoenic changes.(4,10) The International Agency for Research on Cancer (IARC) has concluded that there is inadequate evidence for the carcinogenicity of hydrogen peroxide to humans. There is limited evidence of the carcinogenicity of hydrogen peroxide in experimental animals.(34)

The International Agency for Research on Cancer (IARC) has concluded that this chemical is not classifiable as to its carcinogenicity to humans (Group 3).

The American Conference of Governmental Industrial Hygienists (ACGIH) has designated this chemical as an animal carcinogen (A3).

The US National Toxicology Program (NTP) has not listed this chemical in its report on carcinogens.

Teratogenicity and Embryotoxicity:
There is no human information available. No conclusions can be drawn based on the limited animal information available.

Reproductive Toxicity:
There is no human information available. No conclusions can be drawn based on the limited animal information available.

It is not possible to conclude that hydrogen peroxide is mutagenic. Positive results have been obtained in cultured humans cells.(34) Negative results have been obtained in relevant studies using live animals. Positive results have been obtained in short-term mutagenicity tests.

Toxicologically Synergistic Materials:
Increased airways resistance was observed in volunteers exposed to hydrogen peroxide and sulfur dioxide aerosols at the same time.(2) Exposure to hydrogen peroxide increased the toxicity of ozone in animals.(11)

Potential for Accumulation:
Some hydrogen peroxide undergoes decomposition to oxygen and water when in contact with mammalian tissues, such as skin and the tongue, before absorption. In the body, hydrogen peroxide is readily metabolized to oxygen and water, by one route, or to water alone by another. It does not accumulate in the body.(4)


If symptoms are experienced, remove source of contamination or move victim to fresh air. If symptoms persist, immediately obtain medical attention.

Skin Contact:
Avoid direct contact. Wear chemical protective clothing, if necessary. As quickly as possible, remove contaminated clothing, shoes and leather goods (e.g. watchbands, belts). Immediately flush with lukewarm, gently flowing water for at least 30 minutes. Quickly transport victim to an emergency care facility. Completely decontaminate clothing, shoes and leather goods before re-use or discard. Keep contaminated clothing under water in a closed container until it can be safely discarded.

Eye Contact:
Avoid direct contact. Wear chemical protective gloves, if necessary. Immediately flush the contaminated eye(s) with lukewarm, gently flowing water for at least 30 minutes, while holding the eyelid(s) open. If a contact lens is present, DO NOT delay irrigation or attempt to remove the lens until flushing is done. Neutral saline solution may be used as soon as it is available. DO NOT INTERRUPT FLUSHING. If necessary, continue flushing during transport to emergency care facility. Take care not to rinse contaminated water into the unaffected eye or onto the face. Quickly transport victim to an emergency care facility.

NEVER give anything by mouth if victim is rapidly losing consciousness, is unconscious or convulsing. Have victim rinse mouth thoroughly with water. DO NOT INDUCE VOMITING. If vomiting occurs naturally, have victim rinse mouth with water again. If breathing is difficult, trained personnel should administer emergency oxygen. If breathing has stopped, trained personnel should begin artificial respiration (AR) or, if the heart has stopped, cardiopulmonary resuscitation (CPR) or automated external defibrillation (AED) immediately. Quickly transport victim to an emergency care facility.

First Aid Comments:
Consult a doctor and/or the nearest Poison Control Centre for all exposures except minor instances of inhalation.
Some first aid procedures recommended above require advanced first aid training. Protocols for undertaking advanced procedures must be developed in consultation with a doctor and routinely reviewed.
All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.


Flash Point:
Not combustible (does not burn), but is a strong oxidizing material and can increase the risk or the intensity of a fire.

Lower Flammable (Explosive) Limit (LFL/LEL):
Not applicable

Upper Flammable (Explosive) Limit (UFL/UEL):
Not applicable

Autoignition (Ignition) Temperature:
Not applicable

Sensitivity to Mechanical Impact:
Solutions are not normally shock sensitive, but concentrations greater than 86-90 wt% can be made to detonate if subjected to a high energy source.(20,22)

Sensitivity to Static Charge:
Not sensitive.

Combustion and Thermal Decomposition Products:
Decomposes to molecular oxygen, which can accelerate the burning of flammable materials or cause spontaneous combustion.(20,21,23,24)

Fire Hazard Summary:
Hydrogen peroxide does not burn, but is a strong oxidizing agent. Concentrations of 35% and above can cause combustible materials such as wood, paper, oils and grease to burst into flames and will support, accelerate and intensify the burning of combustible materials. Some substances that do not normally burn in air will ignite or explode upon contact with hydrogen peroxide. The National Fire Protection Association (NFPA) lists hydrogen peroxide solutions (greater than 27.5% up to 52%) as a Class 2 oxidizer, hydrogen peroxide solutions (greater than 52% up to 91%) as a Class 3 oxidizer, and hydrogen peroxide solutions (greater than 91%) as a Class 4 oxidizer. A Class 2 oxidizer will cause a moderate increase in the burning rate or cause spontaneous ignition of combustible materials with which it comes in contact. A Class 3 oxidizer will cause a severe increase in the burning rate of combustible materials with which it comes in contact or that will undergo vigorous self-sustained decomposition due to contamination or exposure to heat. A Class 4 oxidizer can undergo an explosive reaction due to contamination or exposure to thermal or physical shock. In addition, the oxidizer will enhance the burning rate and can cause spontaneous ignition of combustibles.(24) Closed containers may rupture violently due to rapid decomposition, if exposed to fire or excessive heat for a sufficient period of time, or if contaminated with certain metals or dirt. Large amounts of oxygen gas may be released to form an oxygen-rich atmosphere. No part of a container should be subjected to a temperature higher than 49 deg C (120 deg F).(24)

Extinguishing Media:
Hydrogen peroxide does not burn. Use extinguishing media suitable for the surrounding fire. Use large quantities of water as fog to fight fires in which this material is involved.(25) Some chemical extinguishing agents may accelerate decomposition. Carbon dioxide or other extinguishing agents that smother flames are not effective in fires involving oxidizers.(24)

Fire Fighting Instructions:
Use extreme caution. Evacuate area and fight fire from a safe distance or a protected explosion-resistant location or maximum possible distance. Approach fire from upwind to avoid hazardous vapours and decomposition products.
Move containers from the fire area if this can be done without risk. Explosive decomposition may occur under fire conditions. Use extreme caution since heat may cause rupture of containers and release large amounts of oxygen. Otherwise, apply water from as far a distance as possible, in flooding quantities as a spray or fog to keep fire-exposed containers or equipment cool and absorb heat, until well after the fire is out.
Remove all flammable and combustible materials from the vicinity, especially oil and grease. Do not direct water directly on the leak as this may cause the leak to increase. Stay away from ends of tanks, but realize that shrapnel may travel in any direction. Withdraw immediately in case of rising sound from venting safety device or any discolouration of tanks due to fire. In an advanced or massive fire, the area should be evacuated; use unmanned hoseholders or monitor nozzles.
Do not enter without wearing specialized protective equipment suitable for the situation. Firefighter's normal protective clothing (Bunker Gear) will not provide adequate protection. Chemical resistant clothing (e.g. chemical splash suit) with positive pressure self-contained breathing apparatus (MSHA/NIOSH approved or equivalent) may be necessary.


NFPA - Health: 3 - Short exposure could cause serious temporary or residual injury. (hydrogen peroxide aqueous solutions (40% to 60%) or hydrogen peroxide aqueous solution, stabilized (above 60%))
NFPA - Flammability: 0 - Will not burn under typical fire conditions. (hydrogen peroxide, aqueous solutions (40% to 60%) or hydrogen peroxide, aqueous solutions, stabilized (above 60%))
NFPA - Instability: 3 - Capable of detonation or explosive decomposition or explosive reaction, but requires a strong initiating source or must be heated under confinement before initiation, or reacts explosively with water. (aqueous solutions above 60%.) 1 - Normally stable, but can become unstable at elevated temperatures and pressures, or may react vigorously, but non-violently with water. (aqueous solutions 40 to 60%)
NFPA - Specific Hazards: Oxidizing material. (hydrogen peroxide, aqueous solutions (40% to 60%) or hydrogen peroxide, aqueous solutions (above 60%))


Molecular Weight: 34.02

Conversion Factor:
1 ppm = 1.39 mg/m3; 1 mg/m3 = 0.72 ppm at 25 deg C (calculated)

Physical State: Liquid
Melting Point: -33 deg C (-27.4 deg F) (35%); -52.2 deg C (-62 deg F) (50%); -40.3 deg C (-40.5 deg F) (70%); -11.5 deg C (11.3 deg F) (90%) (20,21)
Boiling Point: 108 deg C (226.4 deg F) (35%); 114 deg C (237 deg F) (50%); 125.5 deg C (258 deg F) (70%); 141.3 deg C (286.3 deg F) (90%) (4,20,21)
Relative Density (Specific Gravity): 1.13 (35%); 1.2 (50%); 1.29 (70%); 1.39 (90%) at 20 deg C (water = 1) (4,20,21)
Solubility in Water: Soluble in all proportions.(4,20,21)
Solubility in Other Liquids: Soluble in all proportions in many polar solvents, e.g. low molecular weight alcohols, glycols and ketones; soluble in diethyl ether and carboxylic esters (greater 65%); insoluble in petroleum ether.(4,21,26) (NOTE: Concentrated hydrogen peroxide solutions can react explosively with these solvents.(4,22))
Coefficient of Oil/Water Distribution (Partition Coefficient): Log P(oct) = -0.70 to -1.33 (estimated) (27)
pH Value: 4.6 (35%); 4.3 (50%); 4.4 (70%); 5.1 (90%) (20) (*see note below)
Vapour Density: 1.2 (air=1)
Vapour Pressure: PARTIAL PRESSURE: 0.05 kPa (0.38 mm Hg) at 30 deg C (35%) (21); 0.05 kPa (0.38 mm Hg) (50%); 0.1 kPa (0.74 mm Hg (70%); 0.18 kPa (1.34 mm Hg) (90%) at 20 deg C (4)
Saturation Vapour Concentration: 500 ppm at 30 deg C (35%); 500 ppm (50%); 975 ppm (70%); 1750 ppm at 20 deg C (90%) (calculated)
Evaporation Rate: Not available
Critical Temperature: 457 deg C (855 deg F) (100%) (21)

Other Physical Properties:
ACIDITY: Weak acid; pKa = 11.75 at 20 deg C (Ka = 1.78 X 10(-12) at 20 deg C) (20,21)
VISCOSITY-DYNAMIC: 1.11 mPa.s (1.11 centipoise) (35%); 1.17 mPa.s (50%); 1.23 mPa.s (70%); 1.26 mPa.s (90%) at 20 deg C.(4,21)
VISCOSITY-KINEMATIC: 0.98 mm2/s (0.98 centistokes) (35% or 50%); 0.95 mm2/s (0.95 centistokes) (70%); 0.90 mm2/s (0.90 centistokes) (90%) at 20 deg C (calculated)
SURFACE TENSION: 75 mN/m (75 dynes/cm) (50%); 77 mN/m (70%); 79 mN/m (90%) at 20 deg C.(4)
CRITICAL PRESSURE: 20990 kPa (207 atm.) (21)
*NOTE: The pH of commercial solutions can be affected by the type and amount of stabilizers added, and many times the pH is purposely adjusted to a grade specification range.(19)


Solutions which are completely free of contamination are relatively stable. Stability depends upon many factors including temperature, pH, and the presence of impurities. Alkaline solutions are less stable than acidic ones (the optimum pH is 3.5-4.5). It can decompose in sunlight. Hydrogen peroxide readily liberates oxygen, water and heat.(4,20)

Hazardous Polymerization:
Does not occur.

Incompatibility - Materials to Avoid:

NOTE: Chemical reactions that could result in a hazardous situation (e.g. generation of flammable or toxic chemicals, fire or detonation) are listed here. Many of these reactions can be done safely if specific control measures (e.g. cooling of the reaction) are in place. Although not intended to be complete, an overview of important reactions involving common chemicals is provided to assist in the development of safe work practices.

Hydrogen peroxide solutions (30% or greater) are strong oxidizing agents capable of reacting explosively with many substances. Some organic compounds react with hydrogen peroxide to form unstable peroxides. For a review of the many substances hydrogen peroxide can react with, consult references 25, 28 and 29. These include:
COMBUSTIBLE MATERIALS (e.g. wood, paper, textiles, oil, grease) - may cause fire or explosion upon contact.(20,23,25,28)
STRONG BASES (e.g potassium hydroxide or sodium hydroxide) - can explode violently.(20,25)
NITRIC ACID (more than 50%) or SULFURIC ACID - mixtures with 35% and above hydrogen peroxide can explode violently.(20,25,28)
ORGANIC COMPOUNDS (e.g. carboxylic acids and anhydrides, nitrogen-containing bases, aldehydes, ketones, ethers, alcohols, charcoal, organic dust) - spontaneous combustion, violent decomposition and/or explosion may occur.(20,26,28,29)
METALS (powdered or metal surfaces), METAL OXIDES, METAL SULFIDES METAL SALTS, or IODATES - may cause violent decomposition.(20,25,28)
REDUCING AGENTS (e.g. metal hydrides) - may react violently.(23,29)
POTASSIUM PERMANGANATE - can explode when in contact with very concentrated hydrogen peroxide.(25)

Hazardous Decomposition Products:

Conditions to Avoid:
Heat, open flames, contamination, depletion of stabilizers, pH greater than 4.5.

Corrosivity to Metals:
Hydrogen peroxide solutions (35% and greater) are corrosive (corrosion rate greater than 1.27 mm/year) to carbon steel (types 1010 and 1020 (35-100%); 1075,1095 and 12L14 (100%), grey cast iron, 3% nickel cast iron, ductile cast iron, the nickel base alloys, Hastelloy B and D and Monel, copper, nickel-copper alloy, brass, cartridge brass, bronze, aluminum bronze, naval bronze, silicon bronze, and lead at room temperature.(30,36,37) Hydrogen peroxide solutions attack types 1010 and 1020 carbon steel at any concentration and temperature.(36) One source reports that 50-90% hydrogen peroxide is corrosive to type 3003 aluminum.(36) Hydrogen peroxide solutions (35% and greater) are not corrosive (corrosion rate less than 0.5 mm/year) to stainless steel (e.g. types 303, 304, 316, 17-4PH, 400 series, Carpenter 20Cb-3), aluminum (99.5%), certain aluminum alloys (types 1060, 5052, 6063 and aluminum-magnesium alloys), nickel (100% solution), the nickel-base alloys, Hastelloy C and Inconel, tantalum, titanium and zirconium.(36,37,38) Both stainless steel and aluminum surfaces must be passivated (formation of a protective film by chemical treatment) before use.(20,21)

Stability and Reactivity Comments:
The degree of hazard associated with hydrogen peroxide depends on concentration. Drying of concentrated hydrogen peroxide on clothing or other combustible materials may cause fire. May attack or ignite some forms of plastics, rubber, or coatings.(19)


LC50 (rat): 2000 mg/m3 (4-hour exposure; whole body exposure) (concentration not specified) (3)
NOTE: This value is not considered reliable since a whole body exposure was used and the study was poorly reported.

LD50 (oral, male rat): 1193 mg/kg (35% solution) (4, unconfirmed)
LD50 (oral, female rat): 801 mg/kg (60% solution) (4, unconfirmed)
LD50 (oral, male rat): 75 mg/kg (70% solution) (4, unconfirmed)
LD50 (oral, mouse): 2000 mg/kg (90% solution) (4,12, unconfirmed)

LD50 (dermal, rabbit): approximately 690 mg/kg (90% solution) (4, unconfirmed)

Eye Irritation:

Hydrogen peroxide solutions of 35% and greater are corrosive.

Application of 0.1 mL of 35% hydrogen peroxide caused extreme irritation in rabbits that did not reverse after 22 days. The average score at 24, 48 and 72 hours was 67.7/110 and at 22 days the score was 73/110.(13) A 70% solution was extremely irritating and corrosive to rabbits.(4, unconfirmed)

Skin Irritation:

Hydrogen peroxide solutions of 35% are very mild skin irritants while solutions of 50% and 70% are severely irritating and corrosive respectively.

Very mild irritation was observed in rabbits following a 4-hour exposure to 35%, under cover (average score at 24, 48 and 72 hours 1.25/8).(14) Application of a 50% solution for 4 hours, under cover, was severely irritating to 1 rabbit.(14) In an unpublished study, application of a 35% solution, to intact skin under a cover for 24 hours, caused moderate to severe erythema and slight to very slight edema at 48 hours.(4, unconfirmed) In another unpublished study, application of 70% hydrogen peroxide solution for 30 minutes caused extensive damage to the skin in rabbits and was considered corrosive.(4, unconfirmed)

Effects of Short-Term (Acute) Exposure:

Interpretation of the available inhalation exposure information is complicated because the form of hydrogen peroxide (vapour or aerosol) is not always specified. In general, studies have shown that airborne hydrogen peroxide is irritating to the respiratory tract. Symptoms have included nose irritation and discharge, fluid accumulation in the lungs and necrosis of bronchial tissue. Deaths have been reported.(4,15,16)

Ingestion of lethal doses of a 35% solution has produced tremors, decreased motility, prostration and oral, ocular and nasal discharge in rats. Most animals that died had reddened lungs, bleeding and white stomachs and blood- filled intestines.(4, unconfirmed) In other studies, male mice showed a decrease in body weight and died within 2 weeks when their drinking water contained greater than 1% hydrogen peroxide.(4,5)

Effects of Long-Term (Chronic) Exposure:

Rats were exposed to 67 ppm (93 mg/m3) of an aerosol/vapour mixture generated from 90% hydrogen peroxide for 30 exposures over a 7 week period. There were signs of nasal irritation and profuse nasal discharge after 2 weeks. Autopsy showed lung congestion in all animals. In the same study, two dogs were exposed to 7 ppm (10 mg/m3) of an aerosol/vapour mixture generated from 90% hydrogen peroxide for 6 months. There were no signs of toxicity by 14 weeks except for bleaching and loss of hair. Autopsy showed signs of lung irritation, as well as loss of hair and thickening of the skin.(15)

Several studies have investigated the effects of long-term oral administration of hydrogen peroxide. In general, decreases in body weight gain and biochemical changes have been observed with exposure to lower doses or with exposures of longer durations. Deaths have occurred in animals exposed to doses of 1.5% and higher for 8 weeks or longer. Liver damage and thickening of the stomach wall has been observed in mice administered 0.15% hydrogen peroxide (approximately 230 mg/kg/day) in their drinking water for 16 weeks. This study continued for 35 weeks during which harmful changes in the kidneys, gastrointestinal tract and spleen were also observed.(4,5)

Skin Sensitization:
Negative results were obtained in guinea pigs exposed to 3 or 6% solutions.(4, unconfirmed) No specific information was located for more concentrated solutions.

The International Agency for Research on Cancer (IARC) has concluded that there is limited evidence of the carcinogenicity of hydrogen peroxide in experimental animals.(5,34) The American Conference of Governmental Industrial Hygienists (ACGIH) has designated hydrogen peroxide as an A3 (animal carcinogen).
Several studies have shown that long-term oral administration of 0.1-0.15% hydrogen peroxide causes an inflammatory response in the gastro-duodenal tissue of mice. This inflammatory response may progress to carcinogenic changes. In rats, hydrogen peroxide only induced benign tumours, not malignant tumours, even at nearly lethal concentrations (1-1.5%).(4,10) No neoplasms were observed in hamsters administered 0.75% hydrogen peroxide in dentrifice 5 times/week for 20 weeks. This study is limited by its short duration and the unknown effect of using dentrifice as the vehicle.(34) Hydrogen peroxide did not act as a tumour promoter when administered to rats or hamsters with a known carcinogen.(10,34) No neoplasms were observed in hamsters administered 0.75% hydrogen peroxide in dentrifice 5 times/week for 20 weeks. This study is limited by its short duration and the unknown effect of using dentrifice as the vehicle.(34)

Teratogenicity, Embryotoxicity and/or Fetotoxicity:
No conclusions can be drawn based on the available information.
One historical study which lacks details reported that normal litters were born to 3 female rats exposed to 0.45% in drinking water for 5 months and then mated with unexposed males.(17) No conclusions can be drawn from another poorly conducted study.(4, unconfirmed)

Reproductive Toxicity:
No conclusions can be drawn based on the limited information available.
Male mice were given 0.33% or 1.0% hydrogen peroxide solutions in place of drinking water. The mice were mated after days 7 and 28 or day 21 of exposure. No significant effects on fertility were observed. The concentration, morphology and motility of sperm of mice and rabbits receiving hydrogen peroxide in their drinking water over 3 and 6 weeks remained normal.(18) This study is limited by the small number of animals used and the fact that a control group was not used. Rats were orally administered doses of up to 50 mg/kg orally for 6 months. At the high dose, altered fertility cycles were observed in the females and decreased sperm mobility in males. Treated animals were mated. High dose females produced fewer litters.(4, unconfirmed) There is insufficient information available to evaluate this report.

Negative results have been obtained in most studies using live animals. However, positive results have been obtained in host-mediated assays. In these studies, mutagenicity was observed in bacteria and tumour cells injected into live animals.(4,5,34)
Positive results have been obtained in cultured mammalian cells, including human cells, and in bacteria and yeast..(4,5,34)
Negative results were obtained in fruit flies.(4,5,34)


Selected Bibliography:
(1) Kaelin, R.M.. Diffuse interstitial lung disease associated with hydrogen peroxide inhalation in a dairy worker. American Review of Respiratory Diseases. Vol. 137, no. 5 (May 1988). p. 1233-1235
(2) Toyama, T., et al. Synergistic response to hydrogen peroxide aerosols and sulfur dioxide to pulmonary airway resistance. Industrial Health. Vol. 2 (1964). p. 35-45
(3) Kondrashov, V.A. Comparative toxicity of hydrogen peroxide vapour on inhalation and dermal exposure. English translation. Gigiena Truda i Professionalnye Zabolevaniya. Vol. 21, no. 10 (1977). p. 22-25. (HSE Translation No. 14391 A)
(4) Hydrogen peroxide CAS No. 7722-84-1. Joint assessment of commodity chemicals no. 22. European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC), Sept. 1992
(5) International Agency for Research on Cancer (IARC). Hydrogen peroxide. In: IARC monographs on the evaluation of the carcinogenic risk of chemicals to humans. Vol. 36. Allyl compounds, aldehydes, epoxides and peroxides. World Health Organization, Feb. 1985. p. 285-314
(6) Goette, D.K., et al. Skin blanching induced by hydrogen peroxide. Case reports. Southern Medical Journal. Vol. 70, no. 5 (May 1977). p. 620-622
(7) Grant, W.M., et al. Toxicology of the Eye. 4th ed. Charles C. Thomas, 1993. p. 791-797
(8) Aguirre, A., et al. Positive patch tests to hydrogen peroxide in 2 cases. Contact Dermatitis. Vol. 30, no. 2 (Feb. 1994). p. 113
(9) Barsotti, M., et al. Symptoms of bronchial asthma and eczema in workers assigned to hydrogen peroxide production units. [English summary]. Medicina del Lavoro. Vol. 42, no. 2 (1951). p. 68
(10) Takahashi, M., et al. Effects of ethanol, potassium metabisulfite, formaldehyde and hydrogen peroxide on gastric carcinogenesis in rats after initiation with N-methyl-N'-nitro-N-nitrosoguanidine. Japanese Journal of Cancer Research. Vol. 77, no. 2 (Feb. 1986). p. 118-124
(11) Svirbely, J.L., et al. Enhanced toxicity of ozone-hydrogen peroxide mixture. American Industrial Hygiene Association Journal. Vol. 22, no. 1 (Feb. 1961). p. 21-26
(12) RTECS database record for hydrogen peroxide, 90%. Last updated: 1997/10
(13) Weiner, M., et al. Eye irritation studies on three concentrations of hydrogen peroxide. Journal of the American College of Toxicology. Part B (1990). p. 49-50
(14) Aguinaldo, E.R., et al. Skin irritation studies with hydrogen peroxide. Abstract. Toxicologist. Vol. 12 (1992). p. 110
(15) Oberst, F.W., et al. Inhalation toxicity of ninety percent hydrogen peroxide vapor. A.M.A. Archives of Industrial Hygiene and Occupational Medicine. Vol. 10 (Oct. 1954). p. 319-327
(16) Punte, C.L., et al. The inhalation toxicity of aerosols of 90% hydrogen peroxide. Medical Laboratories Research Report No. 189. Chemical Corps Medical Laboratories. Army Chemical Center, Maryland, May 1953. (NIOSHTIC Control Number: 00068230)
(17) Hankin, L. Hydrogen peroxide ingestion and the growth of rats. Nature. No. 4647 (Nov. 22, 1958). p. 1453
(18) Wales, R.G., et al. The spermicidal activity of hydrogen peroxide in vitro and in vivo. Journal of Endocrinology. Vol. 18 (1959). p. 236-244
(19) Emergency action guide for hydrogen peroxide. Association of American Railroads, Jan. 1990
(20) Eul, W.E., et al. Hydrogen peroxide. In: Kirk-Othmer encyclopedia of chemical technology. John Wiley and Sons, 2005. Available at: <> {Subscription required}
(21) Goor, G., et al. Hydrogen Peroxide. In: Ullmann's encyclopedia of industrial chemistry. 7th ed. John Wiley and Sons, 2005. Available at: <> {Subscription required}
(22) Merrifield, R. Fire and explosion hazards associated with the storage and handling of hydrogen peroxide. Specialist Inspector Report no. 19. Health and Safety Executive, Technology Division, Oct. 1988
(23) Chemical safety sheets: working safely with hazardous chemicals. Kluwer Academic Publishers, 1991
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(25) Fire protection guide to hazardous materials. 13th ed. Edited by A.B. Spencer, et al. National Fire Protection Association, 2002. NFPA 49; NFPA 491
(26) HSDB database record for hydrogen peroxide. Last revision date: 97/05/01
(27) Leo, A., et al. Partition coefficients and their uses. Chemical Reviews. Vol. 71, no. 6 (Dec. 1971). p. 555
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(31) NIOSH pocket guide to chemical hazards. National Institute for Occupational Safety and Health, June 1997
(32) Forsberg, K., et al. Quick selection guide to chemical protective clothing. 4th ed. Van Nostrand Reinhold, 2002
(33) European Communities (EC). Commission Directive 2004/73/EC. Apr 29, 2004
(34) International Agency for Research on Cancer (IARC). IARC monographs on the evaluation of carcinogenic risks to humans. Vol. 71, parts 1, 2 and 3. Re-evaluation of some organic chemicals, hydrazine and hydrogen peroxide. IARC, 1999
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Information on chemicals reviewed in the CHEMINFO database is drawn from a number of publicly available sources. A list of general references used to compile CHEMINFO records is available in the database Help.

Review/Preparation Date: 1998-05-06

Revision Indicators:
WHMIS (proposed class) 1999-03-01
WHMIS (effects) 1999-03-01
WHMIS (disclosure list) 1999-03-01
Carcinogenicity 1999-12-01
Mutagenicity 1999-12-01
Emergency overview 2000-08-01
Acute exposure (ingestion) 2000-08-01
First aid (ingestion) 2000-08-01
ERPG 2001-03-01
NFPA (health) 2003-04-18
WHMIS classification comments 2003-05-13
Important New Information 2003-05-13
PEL transitional comments 2003-12-19
PEL-TWA final 2003-12-19
Resistance of materials for PPE 2004-04-06
EU classification 2004-11-18
EU risks 2004-11-18
EU safety 2004-11-18
EU comments 2004-11-18
Bibliography 2006-03-22
Toxicological info 2006-03-27
Short-term skin contact 2006-03-27
Short-term eye contact 2006-03-27
WHMIS detailed classification 2006-03-27
First aid inhalation 2006-03-27
First aid skin 2006-03-27
First aid ingestion 2006-03-27
Stability/reactivity comments 2006-04-04
Corrosivity to metals 2006-04-04

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