Never mix Sodium hypochlorite (chlorine bleach) with Isopropyl alcohol
Toxic gas
Chloroform and related chlorinated compounds are formed. The reported effects of exposure are dizziness, nausea, headaches and loss of consciousness. Losing consciousness in the presence of the reaction that caused it is what makes this more dangerous than the symptom list suggests, because the exposure continues while the person is unable to leave. Anyone affected should be moved into fresh air immediately and medical advice sought.
Precautions
- Never mix with other cleaning products
- Ventilate the area
- Rinse thoroughly afterwards
- Keep away from children and pets
- Consider professional help
How this happens
Hypochlorite reacts with alcohols to produce chlorinated organic compounds, chloroform among them. No heating and no unusual conditions are required. The domestic route to this is not somebody decanting solvents together: isopropyl alcohol is the active ingredient of many surface sanitisers, screen and electronics wipes and hand rubs, and bleach is what a great many people reach for on the same surfaces. It is therefore a sequential-use hazard in the same way the acid reaction is, and the same rule answers it — use one product, rinse, then use the other if you still need to.
CleaningHQ describes what kind of reaction this is and what it does to a person. It does not publish concentrations, quantities or conditions, because a warning specific enough to be followed is not a warning.
If it has already happened
Get everyone into fresh air straight away, and do not go back inside to open windows. Anyone with breathing difficulty, chest pain, persistent coughing, or a chemical splash to the eyes needs medical attention — treat it as an emergency and call your local emergency number. In the United Kingdom, use NHS 111 or 999 as appropriate; clinicians can consult the National Poisons Information Service.
The substances involved
- Sodium hypochlorite (chlorine bleach) — A powerful oxidising bleach and disinfectant. It is also the substance behind the most common serious household chemical accidents, and must never be mixed with anything.
- Isopropyl alcohol — A solvent that dissolves oils and residues and evaporates without a trace. Useful on electronics and glass; flammable, and damaging to some plastics and finishes.
Evidence
Supported
Recorded as supported rather than strongly supported, and the distinction is deliberate. One authoritative read source states this hazard, on a do-not-mix list rather than as the alert's main subject, and CleaningHQ found no second read source for it during this sprint. That is enough to warn on — warning is cheap and being wrong about it costs a reader nothing but an extra rinse — and not enough to place at the top of the ladder alongside two hazards documented by multiple authorities and by case reports.
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 bleach combined with rubbing alcohol (isopropyl alcohol) forms chloroform, and that the effects include dizziness, nausea, headaches and loss of consciousness. (states this directly)
Verification: a person has read the passage relied on.
Read on — Page 1, the two case reports and the bleach/ammonia and bleach/acid paragraphs; page 2, the "DANGEROUS CHEMICAL COMBINATIONS — DO NOT MIX" list and the safe-work-practices panel. Supports a wider statement — our claim was widened. The register gained authoritative support for three hazards CleaningHQ had not recorded: bleach with alcohols, hydrogen peroxide with acetic acid, and the sequential-use route evidenced by both case reports. Incompatibility records were added for the first two, and the sequential-exposure wording on the existing bleach-and-acid record now rests on a case report rather than on inference.
Last reviewed by a person on .
Last reviewed by a person on .