In the presence of organic matter or if permitted to become alkaline, hydrogen peroxide vigorously decomposes to oxygen and water. There is also a risk of gas embolism and deaths have been reported, but in most cases concentrated solutions of 30-40 per cent were involved. Usually, however, ingestion of hydrogen peroxide results in only mild effects. Any patient symptomatic after ingestion of hydrogen peroxide should be referred to hospital. Essential oils Essential oils, such as clove, eucalyptus or tea tree, may cause toxicity if ingested.
Individual oils vary in toxicity but information is limited.
Essential oils may cause systemic toxicity with coma, respiratory depression, convulsions and in some cases hepatotoxicity and nephrotoxicity. They may also be aspirated and cause respiratory complications. Batteries Button batteries, such as those used in hearing aids, are often ingested by children and sometimes by adults in mistake for tablets. They may cause corrosive effects and some also contain mercury salts which can cause toxicity. Most batteries pass through the gut with no complications.