Combining bleach and hydrogen peroxide

Does it work?

Does not work

Refuted on two regulator sheets that each list the other substance as incompatible. The incompatibility is stated directly; what the combination actually produces in a domestic setting is not.

This is a verdict on whether the technique is effective. Whether it is safe on a particular surface is a separate question, answered below.

Where not to use it

The proposed mechanism

The explanation below is what is offered for this technique. No evidence establishes that this is what actually happens, so treat it as a plausible story rather than as a finding.

Both are oxidisers that destroy chromophores, so a naive additive model suggests more oxidising power. The sheets treat them as incompatible rather than complementary, and no authoritative source states a reaction product for the domestic case.

Background

Bleach and hydrogen peroxide are both oxidising whiteners, which produces the intuition that combining them compounds the effect. Both regulator sheets list the other as incompatible: sodium hypochlorite is stated to be not compatible with hydrogen peroxide, and hydrogen peroxide's own sheet lists ammonia, ammonia carbonates, iodides and sulfites among its incompatibilities. The hypochlorite sheet gives a consequence for its metals reaction — oxygen release and container rupture — and names the peroxide incompatibility in the same sentence. What the combination produces, in what quantity and under what conditions is not stated anywhere: no authoritative source gives a domestic account of it. What can be said without any inference is that two authorities that list incompatibilities list these two against each other, and that the reason the combination is attractive is also the reason it is a poor idea: both are reactive oxidisers, and reactive substances that are already unstable individually do not become more predictable together. Hydrogen peroxide's sheet describes it as REACTIVE and a dangerous explosion hazard in its pure form.

What it does not do

• The sheets state incompatibility without describing what the combination produces domestically
• The concentrations addressed are occupational, not the dilute household solutions

What to use instead

• Sodium percarbonate (oxygen bleach) — An oxidising bleach that releases hydrogen peroxide in water. Gentler than chlorine bleach on fabrics and dyes, and it does not produce chlorine gas.