Why is bleach mixed with ammonia dangerous?

Because together they release chloramine gas, which irritates the eyes, nose, throat and lungs and in serious exposures can cause pneumonia and fluid in the lungs. NMSU's extension publication calls it "a deadly gas." The risk is easy to miss because ammonia hides in products that do not say "ammonia" on the front, most often glass cleaners, multi-purpose cleaners and oven cleaners. Homemade recipes that use household ammonia carry the same risk. If the two have met, leave the room, get to fresh air and call Poison Control at 1-800-222-1222, or 911 for trouble breathing. This page explains the gas, where ammonia turns up, and how to keep the two apart.

Chloramine in plain words

Ammonia is a compound of nitrogen and hydrogen. When it meets the hypochlorite in bleach, chlorine attaches to the nitrogen and forms chloramines, which come off as a gas. Poison Control: ammonia mixed "with a hypochlorite such as bleach makes chloramine gas" [1].

How dangerous it is, in the sources' own words

The sources agree it is harmful and differ in emphasis, and both points are worth knowing.

• Poison Control notes that "Chloramine gas is less volatile than chlorine gas, so it is less likely to cause serious toxicity" [1]. Less volatile means less of it escapes into the air from a given mixture.
• NMSU says: "NEVER mix chlorine bleach and ammonia because this creates a deadly gas" [2].
• The New Jersey Department of Health lists coughing, shortness of breath, chest pain, wheezing, nausea, watery eyes and irritation of the throat, nose and eyes, and warns that serious cases can lead to pneumonia and fluid in the lungs [3].

These fit together. A small, brief exposure may cause only irritation, which is what Poison Control's comparison describes. A larger mixture in a closed bathroom can injure the lungs, which is what NMSU and New Jersey warn about. This page follows the stricter warning for the decision you control: never let the two meet.

Where ammonia hides

NMSU's advice: "Be aware that cleaning products may contain ammonia. Read the ingredient label for ammonia content. Some examples of products with ammonia are glass cleaners, multi-purpose cleaners, and oven cleaners" [2]. Poison Control adds that ammonia is common in glass cleaners [1].

The UF/IFAS cleaner is published without a warning beside the recipe [4], though the same publication tells readers to "NEVER mix bleach with ammonia" elsewhere [4]. If you make it, write "Never mix with bleach" on the bottle. Using ammonia safely is covered on the household ammonia page.

The brand name alone will not tell you whether a product contains ammonia, so read the specific bottle in your hand.

Urine, litter boxes and diaper pails

Many cleaning writers warn against pouring bleach into a litter box, a diaper pail or an unflushed toilet because stale urine smells of ammonia. No agency or extension page reviewed for this page states a measured reaction between bleach and urine, so this page makes no claim about how much gas forms. The ammonia smell itself is the reason for caution: if you can smell ammonia, do not add bleach. Empty and rinse the litter box or pail with water first, and flush the toilet before you clean it. The Washington Poison Center lists diaper pail deodorizers among bathroom products to store safely [5], so read those labels too.

Symptoms to watch for

If anyone collapses, has a seizure, has trouble breathing or cannot be awakened, call 911 immediately. Otherwise leave the area, get to fresh air and call Poison Control at 1-800-222-1222 [6]. The complete steps are on the page for when you have mixed cleaners.

Two habits that prevent it

Pick one product per job. A bathroom cleaned with a bleach product does not need a glass cleaner sprayed on the mirror while the bleach is still wet on the sink. Finish one, rinse, air the room, then start the next; the order is on the one-after-another page.

Store them apart. Keep bleach on a different shelf from ammonia and glass cleaners, so a leaking bottle cannot drip into another. CDC's rule covers every case not listed here: never mix bleach "with any other cleaners or disinfectants" [7].

Choosing a glass cleaner without ammonia

If the bleach bottle is the one you rely on, the simplest protection is a glass cleaner that contains no ammonia. NMSU's vinegar and water recipes are on the glass cleaner page; remember that vinegar is an acid, which must also be kept away from bleach.

References

1. Poison Control (National Capital Poison Center), Williams A. and Klein-Schwartz W., *Chlorine Gas*, undated, read October 2026. https://www.poison.org/articles/chlorine-gas
2. New Mexico State University Cooperative Extension Service, Griffiths R. and Koukel S. (rev.), *Green Alternatives to Toxic Household Products*, Guide G-313, revised February 2019. https://pubs.nmsu.edu/_g/G313/index.html
3. New Jersey Department of Health, *Hazard Alert: Mixing Bleach with Other Cleaning Products Can Be Deadly*, undated, read October 2026. https://www.nj.gov/health/workplacehealthandsafety/occupational-health-surveillance/Hazard_Alert-Mixing-Cleaners.pdf
4. University of Florida IFAS Extension, Griffin A. and Cantrell R.A., *Homemade Household Cleaners*, FCS3319, Release Date October 7, 2025. https://ask.ifas.ufl.edu/publication/FY1449
5. Washington Poison Center, *Poison Safety Checklist*, undated, read October 2026. https://www.wapc.org/wp-content/uploads/Poison-Safety-Checklist.pdf
6. Poison Control (National Capital Poison Center), *First Aid for Poisonings*, undated, read October 2026. https://www.poison.org/first-aid-for-poisonings
7. Centers for Disease Control and Prevention, *Cleaning and Disinfecting with Bleach*, last reviewed April 24, 2024. https://www.cdc.gov/hygiene/about/cleaning-and-disinfecting-with-bleach.html