- What it can be used for
- Cares for teeth and mouth, kills or slows microbes, and oxidizes (in hair dye and bleach) (the functions the EU ingredient database, CosIng, lists for it; a product may use it for any of them)
- CAS number
- 7722-84-1
Why it’s flagged
Allowed in EU cosmetics only with limits.
- Annex III entry 12; applies to: Hydrogen peroxide and other compounds or mixtures that release hydrogen peroxide, including carbamide peroxide and zinc peroxide, with the exception of the foll; products: (a) Hair products; (b) Skin products; (c) Nail hardening products; (d) Oral products, including mouth rinse, tooth paste and tooth whitening or bleaching produc; max (a) 12 % of H2O2 (40 volumes), present or released; (b) 4 % of H2O2, present or released; (c) 2 % of; (e) To be only sold to dental practitioners. For each cycle of use, first use by dental practitioners as defined under Directive 2005/36/EC of the European Parl; required warning: (a) (f) Wear suitable gloves; (a) (b) (c) (e); Contains hydrogen peroxide; Avoid contact with eyes; Rinse immediately if product comes into contact with them.;. Source: EU Cosmetics Regulation, Annex III (restricted)
Annex III (restricted substances) or Annex V (preservatives) of the EU Cosmetics Regulation sets maximum amounts, allowed product types or required warnings.
What the research says
- Only 5 of the 92 chemicals in the database had local (respiratory-tract) NOAECs below the study's own 5th-percentile benchmark — sulfuric acid, trimellitic acid, glutaraldehyde, hydrogen peroxide, and 1,2-dichloro-4-nitrobenzene — and all were strong acids, bases, or reactive irritants that the authors say would already be excluded from consumer aerosol use on physicochemical grounds alone. Moderate evidence. Carthew, Clapp & Gutsell 2009 Industry-funded
- Using an expert job-task-exposure matrix, high occupational exposure to formaldehyde (OR 1.33), glutaraldehyde (OR 1.18), hypochlorite bleach (OR 1.18), hydrogen peroxide (OR 1.19) and enzymatic cleaners (OR 1.33, the only one significant at P<0.001) was each associated with poorer asthma control in US nurses, versus low exposure to the same chemical. Moderate evidence. Dumas 2017
- US nurses exposed to a combination of aldehydes (formaldehyde or glutaraldehyde) plus hypochlorite bleach/hydrogen peroxide plus enzymatic cleaners had the strongest asthma-control signal in the study: odds ratio 1.91 (95% CI 1.31-2.79) for very poorly controlled asthma versus nurses with low exposure to all seven disinfectant categories studied (P-trend=0.001). Moderate evidence. Dumas 2017
Each finding shows its evidence grade. See every graded fact or how we grade.
What this page can’t tell you
These lists describe what a substance can do, its hazard. The risk from one product depends on how much is in it and how you use it, and the label doesn’t say how much.
Not being on a list doesn’t make an ingredient safe. It may never have been assessed.
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Official lists checked September 2026. Spotted a mistake? Tell us.