Nov 12, 2018: Why shouldn’t I mix household chemicals with bleach?

Many chemicals in your home that you use on a regular basis can be dangerous. What many people don’t know is the combination of many of these chemicals can produce dangerous irritating gases.

One of the most common questions we get about household cleaning products concerns the combination use of either an acid with bleach, or ammonia with bleach.

Combining bleach and an acid, such as vinegar or multipurpose bathroom cleaners, causes a chemical reaction that creates chlorine gas. When chlorine gas comes in contact with mucus membranes (such as the nares, eyes, or throat), it gets hydrolyzed into hydrochloric acid.

Combining bleach and ammonia, such as store-bought ammonia or even animal or human urine, causes a chemical reaction that creates chloramine gas. When chloramine gas comes in contact with mucus membranes (such as the nares, eyes, or throat), it releases ammonia and oxygen free radicals.

Low concentrations or short exposures to these gases can cause irritation, pain, burning, and coughing. High concentrations or long exposures can cause corrosive injury, shortness of breath, chemical pneumonia, and lung edema.

The Tennessee Poison Center recommends airing out the area and getting fresh air. Patients with a history of restrictive lung disease are at a higher risk for more severe symptoms like bronchospasm and exacerbation of COPD or asthma. If respiratory symptoms persist, or worsen, patients should call 911 for respiratory support and transport to the closest hospital. The majority of patients have resolution of symptoms with fresh air in one to two hours.

The Tennessee Poison Center is always available and happy to help with any irritant gas exposure.

Question prepared by Nena Bowman, PharmD, DABAT – Managing Director of the Tennessee Poison Center.


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Donna Seger, MD

Medical Director, Tennessee Poison Center

Poison Help Hotline: 1-800-222-1222