The Chemical Incident Management Handbook



Key Points

  • Calcium peroxide is a white or yellowish, odourless powder which is almost tasteless
  • It is a strong oxidiser
  • Calcium peroxide powder is a respiratory and dermal irritant; when in contact with hot water or acid it decomposes to hydrogen peroxide
  • The following information is mainly about hydrogen peroxide except where stated
  • Ingestion of hydrogen peroxide causes gastric irritation and occasionally gas embolism
  • Hydrogen peroxide is irritating to the skin and respiratory tract
  • In the event of a large spill, stay upwind and out of low areas. Ventilate closed spaces. Protective clothing, eye protection and breathing apparatus should be worn

First Aid

  • Terminate exposure and support vital functions
  • The casualty should be moved to an uncontaminated area
  • Rescuers should, ideally, be trained personnel and must be careful not to put themselves at risk and so wear appropriate protective clothing and, if available, breathing apparatus
  • If the casualty is unconscious a clear airway should be established and maintained; give 100% oxygen if available
  • Inhalation Exposure: If the patient stops breathing, expired air resuscitation should be started immediately using a pocket mask with a one way valve, if available. It is important where the face is contaminated that expired air resuscitation is NOT attempted unless an airway with rescuer protection is used
  • Dermal Exposure: Remove contaminated clothing, if possible under a shower and place in double, sealed, clear bags and label; store the bags in a secure area and away from patients and staff
  • Wash the skin thoroughly with copious amounts of water
  • Eye exposure: Irrigate the eyes thoroughly with water or saline for 15 minutes
  • Oral exposure: Encourage small quantities of oral fluids (no more than 50-100 ml in total)

Detailed Information

Calcium peroxide

  • Calcium peroxide is a white or yellowish, odourless powder which is almost tasteless
  • Common synonyms calcium superoxide, calcium dioxide
  • CAS 1305-79-9
  • UN 1457
  • NIOSH/RTECS EW 3865000
  • Molecular formula CaO2
  • Molecular weight 72.08
  • Calcium peroxide is used as a rubber stabiliser, seed disinfectant, antiseptic, and in bleaching of oils, modification of starches and high temperature oxidation
  • It sinks in cold water; it is soluble in acid with the formation of hydrogen peroxide
  • Calcium peroxide is a strong oxidation agent, it is a dangerous fire risk when in contact with organic materials

Summary of Human Toxicity

Calcium peroxide

  • Calcium peroxide is an irritant to the mucous membranes, respiratory tract and skin in high concentrations
  • Occupational Exposure Standards: no data available

Hydrogen peroxide

  • Hydrogen peroxide acts on exposed tissues by releasing oxygen; for each volume of 3% solution, 10 volumes of oxygen may be produced1
  • Exposure to 3%, household strengths, of hydrogen peroxide by ingestion, dermally or in the eye does not normally give rise to toxic effects
  • Inhalation of 90% hydrogen peroxide causes nasal irritation, increased saliva, a scratchy feeling of the throat and respiratory tract inflammation2
  • Solutions of >10% on the skin may cause burns
  • Ingestion is the main route of exposure and causes gastrointestinal irritation
  • There is also a risk of gas embolism which although not common from ingestion has occurred after the use of hydrogen peroxide for irrigation of body cavities
  • Several deaths from ingestion are reported in the literature; in most cases the exposures were to concentrated solutions of 30-40%. One case reported a 49- year-old female ingesting 240 ml of a 35% solution; she died 78 hours later3
  • Cerebral infarction, believed to have resulted from gas embolization of the cerebral vasculature, has been reported in an 84-year-old man who took 30 ml of 35% hydrogen peroxide diluted in 100-300 ml of water4
  • Multiple brain emboli occurred in a 63-year-old who ingested 120 ml of 35% solution; he recovered5
  • Occupational Exposure Standards:
      Long-term exposure limit: 1 ppm (1.4 mg . m-3)
    Short-term exposure limit: 2 ppm (2.8 mg . m-3)

Acute Clinical Effects

Inhalation Effects

Calcium peroxide

  • Respiratory tract irritant with coughing, wheezing, shortness of breath and potential chemical pneumonitis

Hydrogen peroxide

  • Transient dyspnoea and cough; with concentrated solutions there may be more severe irritation and inflammation of the respiratory tract

Dermal Effects

Calcium peroxide

  • Skin irritation, blistering and burns may occur

Hydrogen peroxide

  • Skin irritation with paraesthesia, blistering and whitening; solutions >10% may cause burns

Eye Effects

Calcium peroxide

  • Irritating to eyes

Hydrogen peroxide

  • Irritation with a burning sensation, conjunctival hyperaemia, lacrimation and severe pain which should resolve in a few hours, but with more concentrated solutions resolution may by up to 24 hours
  • There are rare cases of temporary corneal injury resulting from application of 3% solution to the eye6

Oral Effects

Calcium peroxide

  • Irritant to gastrointestinal tract; nausea and vomiting may be experienced

Hydrogen peroxide

  • Irritation of the gastrointestinal tract, the severity of which depends on the concentration of the solution
  • Vomiting is common, and the vomitus may be frothy due to the liberation of oxygen (risk of aspiration)
  • Haematemesis and gastric distension, due to the release of oxygen, may occur
  • Lethargy, coma, convulsions and respiratory arrest have been reported7
  • Gas embolism has been reported in several cases of ingestion of hydrogen peroxide
  • In severe cases ischaemic ECG changes and EMD (electromechanical dissociation) may be seen because of embolisation of the heart, restricting blood flow8
  • Cerebral infarction and multiple brain embolism may occur in severe cases

Chronic Clinical Effects

Hydrogen peroxide

Chronic exposure to an aerosol of hydrogen peroxide in a concentration of 41 mEq . m-3 (1 ppm = 1.41 mg . m-3) resulted in chronic diffuse interstitial lung disease.9 Although no cases have been reported, chronic ingestion could cause gastritis.


For both hydrogen and calcium peroxide

Inhalation Management

  • Maintain a clear airway, give humidified oxygen and ventilate if necessary
  • If respiratory irritation occurs assess respiratory function and if necessary perform chest X-rays to check for chemical pneumonitis
  • Patients should be kept at rest
  • Treat pulmonary oedema with PEEP or CPAP ventilation
  • Symptomatic and supportive care

Dermal Management

  • Remove any remaining contaminated clothing, place in double, sealed, clear bags and label; store in a secure area away from patients and staff
  • Irrigate with copious amounts of water
  • Treat irritation symptomatically
  • Bleaching of the skin usually resolves within a few hours

Eye Management

  • Irrigate thoroughly with running water or saline for 15 minutes
  • Stain with fluorescein and refer to an ophthalmologist if there is any uptake of the stain

Oral Management

  • Gastric decontamination is not worthwhile for ingestion of hydrogen peroxide due to its rapid dissociation.
  • Encourage oral fluids unless there is evidence of severe injury
  • If gastric distension is severe a fine bore gastric tube may be passed to aid the release of gas
  • In cases with severe clinical effects patients should be X-rayed to check for the presence of gas emboli
  • If facilities are available endoscopic evaluation should be undertaken within 12 hours of the event in any patient with haematemesis, persistent vomiting or other evidence of gastric burns to assess the extent and severity of the injury
  • Monitor ECG in severe cases
  • Hyperbaric oxygen therapy has been suggested for patients with evidence of cerebral embolism due to hydrogen peroxide4
  • Contact a poisons information service for further guidance

Summary of Environmental Hazards

Calcium peroxide

  • The effects of low concentrations of calcium peroxide on aquatic life is unknown
  • It may be dangerous if it enters water supplies

Hydrogen peroxide

  • Gaseous hydrogen peroxide is a common air contaminant; it may concentrate in cloud water
  • Persistence is unlikely because of the strong oxidising activity of this chemical
  • Hydrogen peroxide does not concentrate in the food chain
  • It decomposes to water and oxygen
  • Drinking Water Standards: no data available
  • Soil Guidelines: no data available
  • Air Quality Standards: no data available


1. Gosselin RE, Smith RP & Hodge HC. Clinical Toxicology of Commercial Products, 5th edn. Williams & Wilkins, Baltimore, 1984

2. Oberst FW, Comstock CC & Hackley EB, 1954. Inhalation toxicity of ninety percent hydrogen peroxide vapor. Indust Hyg Occup Med; 10: 319-27

3. Litovitz TL, Felberg L, Soloway RA, Ford M & Geller R, 1995. 1994 Annual report of the AAPCC toxic exposure surveillance system. Am J Emerg Med; 13(5): 551-97

4. Sherman SJ, Boyer LV & Sibley WA, 1994. Cerebral infarction immediately after ingestion of hydrogen peroxide. Stroke; 25(5): 1065-7

5. Ijichi I, Itoh T, Sakai R, Nakaji K, Miyauchi T, Takahashi R, Kadosaka S, Hirata M, Yoneda S, Kajita Y & Fujita Y, 1997. Multiple brain embolism after ingestion of concentrated hydrogen peroxide. Neurology; 48(1): 277-9

6. Grant MW & Schuman JS. Toxicology of the Eye, 4th edn. Charles C Thomas, Springfield, 1993

7. Giberson TP, Kern JD, Pettigrew DW, Eaves CC & Haynes JF, 1989. Near-fatal hydrogen peroxide ingestion. Ann Emerg Med; 18(7): 778-9

8. Christensen DW, Faught WE, Black RE, Woodward GA & Timmons OD, 1992. Fatal oxygen embolization after hydrogen peroxide ingestion. Crit Care Med; 20(4): 543-4

9. Ellenhorn MJ, Schonwalds S, Ordog G & Wasserberger J. Ellenhorn's Medical Toxicology - Diagnosis and Treatment of Human Poisoning, 2nd edn. Williams & Wilkins, London, 1997