Everyday Hazmat: The Inappropriate Mixing of Household Chemicals


In 2006, the American Association of Poison Control Centers reported 214,091 calls associated with household cleaning products, the number 3 category on its list of the top 25 compounds frequently involved in human exposures.1 My unit is frequently called to the scene where civilians have become ill from inappropriately mixing household cleaning chemicals. Many of these responses are not limited to homes; they have been to hotels, schools, and even a local hospital. The literature also contains reports on two separate mass-casualty incidents involving U.S. Army barracks. What is most troubling to me is the perception among the public and even some first responders that household cleaning products are not dangerous, even when they combine and form a noxious vapor cloud. These products include household ammonia, household bleach, and acid-based cleaners. These everyday hazmat incidents do not evoke headlines in the media. Instead, the EMS and fire crews respond to find one patient, maybe two patients, seemingly more embarrassed than ill, where a refusal of medical assistance (RMA) is more likely than decontamination and transport.

A study conducted by the New York State Department of Health from 1993 to 1998 noted that first responders constituted 15 percent of the reported injuries from ammonia incidents.2 These injuries and illnesses were preventable. The cluster of symptoms caused by exposure to these irritant gases is referred to as “Irritant Gas Toxidrome” (Table 1). Chlorine and ammonia are two major chemicals that are responsible for irritant gas toxidrome. When inhaled, they dissolve in the respiratory tract mucosa and cause inflammation. Damage to the respiratory system is related to the solubility and concentration of the gas or gases. The signs and symptoms associated with the Irritant Gas Toxidrome may be acute or delayed. Acute effects include eye, nose, and throat irritation; dyspnea; cough; stridor, bronchospasm; vomiting in some cases; and noncardiogenic pulmonary edema. Later, subacutely, opportunistic bacterial infections can occur with progression to pneumonia and bronchitis.

The duration of exposure and the concentration of the product will vary according to the concentrations of the individual products before mixing. Standard household bleach is actually sodium hypochlorite in solution and ranges from three to 10 percent in solubility, which is described as moderately water soluble. Household ammonia, known as ammonium hydroxide, ranges around five to 10 percent, which is still considered highly water soluble. Note: Some literature refers to household ammonia as aqua ammonia, given that it is significantly less concentrated than ammonium hydroxide. There are many other concentrations of these products available for commercial purposes; however, most of the incidents to which we respond involve the household strengths.

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Other variables to consider are the relative size and ventilation of the area where the mixing occurs. Since most of these situations occur in and around the bathroom, it is no surprise that the relatively high concentration of vapor in the small area leads to an immediate onset of the signs and symptoms of exposure that are so noxious that they drive the person away. Both ammonia and chlorine vapors dissipate in the atmosphere; therefore, after ventilation, the area will be habitable in a relatively short time. Individuals trained in hazardous materials should mitigate the leftover compounds and acids created.




Mixing bleach with ammonia cleaners forms monochloramine (NH2Cl), dichloramine (NHCL2), and trichloramine (NCL3— nitrogen trichloride) compounds. Chloramines are inorganic nitrogen compounds that contain one or more chlorine atoms attached to a nitrogen atom.3 The chloramines are alkaline but are slightly less water soluble than ammonia, causing them to bubble out of solution. Many victims have reported seeing a milky white solution that bubbles and creates a noxious cloud.

In the commercial and industrial setting, chloramines are used as a bacteriocidal agent to treat water, since they stay in the water distribution system longer than chlorine. They are also used in the synthesis of many chemicals and plastics. Trichloramine is the most volatile of the three compounds and is more readily released into the air. The chloramine compounds are responsible for what is described as that typical “indoor swimming pool smell.” They decompose in water to form hypochlorous acid and free ammonia gas; the former combines with moisture and forms hydrochloric acid. The latter is a respiratory and mucous membrane irritant and can cause ulcerative tracheobronchitis, chemical epiglottitis in the pediatric population, noncardiogenic pulmonary edema (NCPE), and pneumonitis. Persistent hypoxemia as a consequence of exposure to irritant gases is associated with a high mortality. Ocular burns and corneal abrasions have occurred with serious exposure, but damage is rarely permanent.

Patients will often report a burning pain in the chest and upper airway and stinging eye irritation. Those who have asthma or chronic obstructive pulmonary disease will most likely experience an exacerbation of these conditions. Children exposed to the same levels of ammonia vapor as adults may receive a larger dose because they have greater lung surface area to body weight ratios and increased minute volumes per kilogram weight. In addition, they may be exposed to higher levels than adults in the same location because of their short stature and the higher levels of ammonia vapor found nearer to the ground. Also, humans exposed to ammonia vapors experience olfactory fatigue, making it difficult to further detect the smell of ammonia, which can in turn increase exposure time. Finally, since chloramines have nitrogen in their chemical composition, it is possible that methemoglobinemia will develop, although the exposure would likely be severe, if not fatal.




Another common occurrence is the mixing of bleach and an acid-containing cleaner, which often causes a violent reaction. This generally occurs when the do-it-yourselfer is attempting to clear a stubbornly clogged drain at 3 a.m. In the end, it would have been cheaper and less painful to call a plumber. Common household toilet bowl cleaners and fungicides are usually moderately strong acids like phosphoric acid and sodium bisulfate, which have a pH around two. Drain cleaners, like the stronger sulfuric acid, are dense, oily liquids with a pungent odor. Depending on its purity, sulfuric acid may be colorless to dark brown. Simply mixing sulfuric acid and water can be particularly dangerous because the mixing produces a large amount of heat, which can cause violent spattering. Add an alkaline or another product, and you have a fuming corrosive.

Bleach mixed with an acid creates an acid halide that liberates chlorine vapors as well as some water. Chlorine reacts with the water to form hydrochloric and hypochlorous acids. Chlorine gas, which is less alkaline than ammonia, is 30 times more irritating to skin tissues than straight hydrochloric acid. Remember that this substance, which was once used as a weapon in World War I, causes a variety of symptoms in accordance with the severity of the exposure. Hydrochloric acid is created when chlorine contacts the moisture in the respiratory mucosa, causing a burn injury. Toxic, free-radical oxygen is released, which also causes tissue inflammatory response and damage. Some bleach and toilet bowl cleaner labels warn against mixing with other chemicals. However, human nature being what it is, these warnings are often unheeded.

The chlorine vapors that are liberated have a detectable odor (odor threshold) as low as 0.021 parts per million (ppm) in air; mild mucous membrane irritation may occur at levels as low as one ppm. A level of at least three ppm may cause extreme irritation of the eyes and respiratory tract. Symptoms following exposure to chlorine include irritation of the eyes, nose, and throat; dizziness; cough; bronchospasm, epigastric burning; and chest pain and atelectasis.4

Chlorine is transformed into chloride ions (normal components of human biochemistry) in the body. An enormous amount of chlorine has to be inhaled or ingested to detect a significant increase in chloride ions in the blood, which leads to a severe metabolic acidosis. Severe exposure may cause pulmonary edema and bronchiolar and alveolar damage; the literature contains reports of pneumomediastinum, presumably from the corrosive tissue destruction by the inhaled product.5 Only four case reports on chlorine toxicity from mixing bleach with acid cleaning agents have been published, including one that describes near-fatal pulmonary edema and, two, pneumomediastinum. Chlorine irritates the skin and can cause burning pain, inflammation, and blisters.

Children may be more vulnerable than adults to chlorine’s corrosivity because of the smaller diameter of their airways. Children may also be more vulnerable to gas exposure because of increased minute ventilation per kilogram.




Also known as improvised chemical devices (ICD), bottle bombs most often are created by children who are showing their mastery of chemistry on YouTube or in an attempt to get out of that midterm examination. Reactive chemicals that are mixed begin to combust in a process known as a “hypergolic reaction.” The chemical reaction progresses within the container, causing it to bulge or expand until it ruptures explosively. Since force is amplified several times in enclosed spaces, the potential for injuries grows. It takes only one to five pounds per square inch (psi) to break a window or your tympanic membrane. During the New York City crack cocaine epidemic of the 1990s, one form of ICD was deployed at locations where drugs were sold or made, as a deterrent to rival dealers and investigating police officers. These devices can be made with any size of plastic soda or drink bottle—from 20-ounce to three-liter bottles to larger containers. After these devices explode, people usually report a strong or unusual chemical odor near the location. Most times, however, the shattered remains of a soda bottle are the only remaining evidence. Medical management of these patients is consistent with that for blast trauma. Responders are also reminded to be sure to address the potential inhalation injuries from the liberated gases and chemicals as well as the dermal and ocular chemical splash burns of the caustics involved.6




In August 2008, police and fire units in Pasadena, California, responded to a suicide involving hydrogen sulfide. The victim, found dead in his car, had mixed a fungicide and an acid toilet bowl cleaner in a plastic tray. First responders saw the tray with a “bright blue liquid” in the back seat of the vehicle. It was learned in the ensuing investigation that he may have visited one or more of the numerous Japanese Web sites that provide information on how to commit suicide using hydrogen sulfide. In Japan, press reports indicated that during the first six months of 2008, more than 100 people had committed suicide by inhaling hydrogen sulfide produced by mixing commonly available chemicals. Mixing acids with certain fungicides, pesticides, dandruff shampoos, and other products containing sulfur or sulfates can liberate hydrogen sulfide gas.

Hydrogen sulfide (H2S), also known as sewer gas, is a highly toxic gas with an odor of rotten eggs at low concentrations. At higher concentrations, olfactory fatigue rapidly occurs, making odor a poor warning symptom of danger. All of these compounds are direct irritants, but their major method of toxicity is interference with the cells’ use of oxygen. Low-level exposures irritate the eyes, nose, and throat and cause a cough, headache, nausea, and dizziness. Higher exposures can cause syncope, seizures, coma, tracheobronchitis, and pulmonary edema (which may occur up to 48 to 72 hours later). Death may occur within minutes of an acute massive exposure.




The first-arriving units must adequately size up the situation, transmit this information to the dispatcher, and request the response of the local hazardous materials unit. By taking into consideration the time of day, the occupancy type, and the victims’ signs and symptoms, you can immediately get a rough idea of how large this incident is and how large an event it can evolve into. It is imperative that you set up and enforce hazard control zones. Only responders with appropriate personal protective equipment and respiratory protection should enter the area. Protecting yourself and your crew is paramount. Do not rely on odor as a means of determining whether it is safe to enter an area or, worse, to identify the product. Hazardous materials responders should perform air monitoring for chlorine and ammonia and determine if the area is safe to enter.

If you suspect that a bottle bomb has gone off, if you find a suspicious bottle, or if you observe a bottle that is fuming or bulging, do not handle it, because it is impossible to tell when it will detonate. Isolate the device as if it were any other type of explosive. Decontamination is generally done by removing the individual’s outer garments, since the weave of certain fabrics can trap gases and lead to continued exposure by “off-gassing.” Decontaminate individuals with splash injuries in the usual manner—hazardous materials personnel using soap and water. Manage the patient as a caustic injury.

Care in the prehospital setting is generally supportive while following local protocols. However, it is compulsory to monitor oxygen saturation. Textbooks and the literature cite the efficacy of treating symptomatic patients with beta-2 agonists; administer this therapy as per local protocol. Treatment of hydrogen sulfide patients consists of administering the contents of the cyanide kit without the sodium thiosulfate; the patients may also benefit from hyperbaric therapy.

Some authors suggest using nebulized sodium bicarbonate in symptomatic chlorine-injured patients; however, the experts do not agree on its benefit for chloramine exposures. They cite a lack of clinical evidence for this therapy. Be aware that this therapy is nothing more than neutralizing an acid in-vitro, creating an exothermic reaction Most recently, the Louisiana Department of Public Health’s Morbidity Report on the effects of exposure to bleach/ammonia and bleach and acid exposures during the Hurricane Katrina cleanup recommended that care providers combine three milliliters of sodium bicarbonate 8.4 percent with two milliliters of normal saline for patients experiencing symptomatic exposures to inhale by nebulizer.7

Nelson writes in Goldfrank’s Toxicology that nebulized four percent sodium bicarbonate given to chlorine-poisoned sheep improved oxygenation but failed to reduce overall mortality.8 The use of inhaled or parenteral steroids is reportedly not shown to be helpful in victims of irritant gas explosions.

Patients who develop pulmonary edema benefit from positive end expiratory pressure ventilation and not standard diuresis and nitrate therapy, as in cardiogenic pulmonary edema. Here, the heart is not failing as a pump, but the pathology is a result of an overwhelming inflammatory response and damage to the alveolar basement membrane.

The issue of noncardiogenic pulmonary edema post exposure (NCPE) is most perilous for EMS providers. Mildly symptomatic patients can resolve over time, and many will refuse care and transportation to the hospital. However, the onset of NCPE can depend on the length and severity of the exposures and the patients’ co-morbidities. It could happen within minutes of exposure or can be delayed up to 24 hours. Doctor W.P. Herringham explained in the Lancet that the onset of NCPE in chlorine-exposed World War I casualties was hastened by moderate exercise, such as the effort exerted in escaping from a vapor cloud. (3)Therefore, it is perilous to accept an RMA out of hand; it is prudent to consult with your online medical control physician to execute an RMA. Remember the TEST acronym widely used in WMD/hazmat awareness programs: If you don’t Touch, Eat, Smell, or Test a product, you will not end up a patient. In this case, it is the secret to going home with an intact respiratory tract.




1. “Bronstein A. et al. (2007) “2006 Annual Report of the American Association of Poison,” Control Centers’ National Poison Data System (NPDS), Clinical Toxicology, 45:8, 815-917. Available online: http://dx.doi.org/10.1080/15563650701754763.

2. “Hazardous Substance Emergency Events Surveillance Project Report, Ammonia Spills, New York State 1993-1998,” New York State Department of Health. Available online: http://www.health.state.ny.us/environmental/chemicals/hsees/ammonia.htm/.

3. Pascuzzi TA, AB Storrow, “Mass casualties from acute inhalation of chloramine gas,” Military Medicine 1998, 163 (2):102-104.

4. “Homemade Chemical Bomb Events and Resulting Injuries–Selected States, January 1996-March 2003,” CDC MMWR. July 18, 2003; 52(28):662-664.

5. Gapany-Gapanavicius M, A Yellin, S Almog, M Tirosh, “Pneumomediastinum–a complication of chlorine exposure from mixing household cleaning agents,” JAMA 1982; 48:349-50.

6. New Jersey Dept. of Community Affairs, Division of Fire Safety, “Bottle Bombs,” 2003, http://www.state.nj.us/dca/dfs/bombs.htm/.

7. Louisiana Dept. of Public Health. Morbidity Report, 17:2, March-April 2006. Accessed at http://www.dhh.louisiana.gov/offices/publications/pubs-205/marapr06DontMixWithBleach.pdf/.

8. Goldfrank L, et al. Goldfrank’s Toxicological Emergencies, 7th edition (USA: McGraw Hill), 1457-1561.

Additional References

Centers for Disease Control and Prevention, “Ocular and Respiratory Illness Associated with an Indoor Swimming Pool—Nebraska, 2006,” MMWR 2007; 56:929-932.

Faigel, HC, “Hazards to health: mixtures of household cleaning agents,” N Engl J Med 1964; 271:618

Gapany-Gapanavicius M, M Molho, M Tirosh, “Chloramine-induced pneumonitis from mixing household cleaning agents,” Br Med J 1982; 285:1086.

Jones, FL, “Chlorine poisoning from mixing household cleaners” [Letter]. JAMA 1972; 222:1312.

Reisz, GR, RS Gammon, “Toxic Pneumonitis from Mixing Household Chemicals,” Chest 1986; 89:49-52.

Urbanetti, S, “Toxic Inhalational Injuries,” Medical Aspects of Chemical and Biological Warfare. Textbook of Military Medicine. Accessed at http://www.au.af.mil/au/awc/awcgate/medaspec/Ch-9electrv699.pdf/.

LOUIS COOK, EMT-P, is a 22-year veteran of EMS and a lieutenant assigned to the Fire Department of New York Special Operations Command, Haz Tac Battalion. He is a rescue technician, hazmat technician, and diver medical technician.


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