Hydrogen peroxide
An oxidising bleach that breaks down into water and oxygen. Genuinely milder than chlorine bleach, and not therefore safe to combine with anything.
What not to do
These are the combinations an authority has warned about. It is not a list of everything dangerous: a substance nobody has warned about has not been cleared, and none of this is permission to mix.
Never mix
Peracetic acid is formed, which irritates the eyes, skin and lungs. This is a materially less severe outcome than the chlorine and chloramine hazards, but the combination is widely recommended online as a produce wash and a surface treatment, usually with the reassurance that neither ingredient is anything to worry about.
Hydrogen peroxide is unsafe on Laptop keyboard
Unsafe
Do not do this. The risk is established, and it is described below.
Evidence
Supported
Sources
Guidance for Keeping Your Dell Technologies Equipment Clean
Dell Technologies · Manufacturer documentation
Relied on for: That hydrogen peroxide and other peroxides are among the named substances that must not be used on the equipment. (states this directly)
Sodium hypochlorite (chlorine bleach) must never be mixed with Hydrogen peroxide
Unsafe
Do not do this. The risk is established, and it is described below.
Two oxidisers, which is why the combination is attempted. The regulator lists them as incompatible with each other.
Precautions
- Never mix with other cleaning products
- Ventilate the area
- Wear eye protection
Evidence
Strongly supported
Sources
Right to Know Hazardous Substance Fact Sheet: Sodium Hypochlorite
New Jersey Department of Health · Government or regulator
Relied on for: That sodium hypochlorite is not compatible with hydrogen peroxide. (states this directly)
Right to Know Hazardous Substance Fact Sheet: Hydrogen Peroxide
New Jersey Department of Health · Government or regulator
Relied on for: That hydrogen peroxide is corrosive, reactive and an oxidiser carrying its own incompatibility list. (states this directly)
Precautions
- Never mix with other cleaning products
- Wear eye protection
- Wear gloves
- Test on an inconspicuous area first
- Keep away from children and pets
In detail
Hydrogen peroxide is the oxidising agent behind oxygen bleaches, whether sold as a solution or generated in water from a solid such as sodium percarbonate. It bleaches by the same route as any other oxidant, breaking the chromophores that make a stain visible, and its decomposition products are water and oxygen, which is the basis of its reputation as the environmentally preferable bleach. That reputation is largely deserved and is routinely over-extended. Being milder than hypochlorite does not make it inert: it is an oxidiser, it damages some dyes and finishes, and concentrated solutions are corrosive to skin and eyes. It also has one specific interaction that its gentle reputation actively obscures — combined with vinegar it forms peracetic acid, a more aggressive oxidising agent that irritates the eyes, skin and lungs, and the combination circulates widely as a two-step surface treatment precisely because both ingredients have gentle reputations. The rule is the general one for any cleaning agent: use it on its own, and rinse before using anything else.
Properties
- Chemical name
- Hydrogen peroxide
- pH
- Mildly acidic
Why
- Hydrogen peroxide is explained by Oxidation and bleaching
- Hydrogen peroxide is explained by Oxidation and bleaching
Hacks and claims involving this
- Oxygen bleach is the wool-safe bleach Does not work
- Spraying hydrogen peroxide and vinegar in sequence Does not work
- Combining bleach and hydrogen peroxide Does not work
- A hydrogen peroxide and bicarbonate paste on a stain Disputed
Sources for this page
Sources
Hazard Alert — Worker Health and Safety: Mixing Bleach with Other Cleaning Products Can Be Deadly
New Jersey Department of Health, Environmental and Occupational Health Surveillance Program · Government or regulator
Relied on for: That hydrogen peroxide combined with vinegar forms peracetic acid, which irritates the eyes, skin and lungs. (states this directly)
Kirk-Othmer Encyclopedia of Chemical Technology
John Wiley & Sons · Reference work
Relied on for: That hydrogen peroxide is an oxidising bleach acting on chromophores and decomposing to water and oxygen. (background and mechanism only)