Ammonia works.

Its alkalinity can help dissolve grease and soil, which is why ammonia has been used for generations in glass cleaners, degreasers, floor products, multipurpose cleaners, and commercial cleaning formulations.

But cleaning performance is only one part of the formulation decision.

Ammonia is also: volatile, irritating to the eyes and respiratory tract, capable of causing corrosive injury at sufficiently high concentrations, and involved in thousands of documented accidental childhood cleaning-product exposures.¹⁻⁵

Because ammonia readily moves from a cleaning solution into the surrounding air, using it can create an inhalation exposure in addition to whatever contact occurs with the cleaned surface.¹⁻³

Accidental exposure is also a real-world consideration.

A 2026 analysis of the U.S. National Poison Data System identified 6,104 unintentional exposures to ammonia-containing household cleaning products in children younger than six between 2016 and 2023. Among ammonia exposures for which a medical outcome was known, 22 produced moderate effects and two produced major effects.⁵

And ammonia has an additional hazard that many other cleaning ingredients do not:

It can react with chlorine bleach to generate toxic chloramine gases.

Published medical literature documents life-threatening toxic pneumonitis after people accidentally mixed household ammonia and bleach.⁶

Repeated occupational exposure matters as well. Studies of professional cleaning workers have associated ammonia use with asthma symptoms, and a systematic review of cleaning-worker studies identified ammonia, bleach, cleaning sprays, and mixing cleaning products among exposures associated with occupational asthma and rhinitis.⁷˒⁸

For households with pets, exposure can occur in ways that are easy to overlook. Dogs and cats may walk through a freshly cleaned area, lick product from their paws or coat, investigate a bucket or spill, or inhale vapors near a cleaning area. Veterinary toxicology references specifically identify ammonia among alkaline cleaning chemicals capable of causing skin and eye burns, respiratory irritation, coughing, and lung injury at sufficiently high exposure.⁹

For No Nines™, the question is therefore not whether ammonia can clean.

It can.

The question is whether the cleaning function requires introducing a volatile respiratory irritant with accidental-exposure and chemical-mixing hazards when the intended cleaning function can be accomplished without it.

For us, it does not.

No Nines™ Standard™

Effective chemistry doesn't require unnecessary exposure.

Our ingredient decisions consider not only whether an ingredient can perform a function, but also how much is required, how people are exposed to it, what happens when it is misused, and whether a different chemistry can accomplish the intended purpose with a more favorable exposure profile.

What Is Ammonia?

Ammonia is a nitrogen-containing compound with the chemical formula NH₃.

At room temperature, pure ammonia is a colorless gas with a distinctive pungent odor. In household and commercial cleaning products it is generally used dissolved in water, commonly described as aqueous ammonia or, on some product documentation, ammonium hydroxide.¹˒²˒¹⁰

In water, ammonia creates an alkaline solution.

That alkalinity helps explain its cleaning performance. Alkaline chemistry can assist in loosening or removing grease, oils, fingerprints, and other soils.

But ammonia also has another important property:

It is volatile.

Some ammonia can leave an aqueous cleaning solution and enter the surrounding air.

So exposure does not necessarily end at the surface being cleaned.

The Poison-Center Data: Children Really Are Exposed

Accidental childhood exposure to household cleaning products is not hypothetical.

A particularly useful analysis was published in BMC Pediatrics in 2026 using U.S. National Poison Data System records from 2016 through 2023.⁵

Researchers identified 633,317 unintentional household-cleaning-product exposures in children younger than six during the eight-year study period.

The overwhelming majority occurred where the products are ordinarily used and stored:

• 97.2% occurred in the home
• 84.1% involved children younger than three
• 44.7% involved children between one and two years old
• 87.7% were managed at the exposure site rather than a healthcare facility⁵

Those figures include all household-cleaner categories, not ammonia alone.

But the researchers were also able to separate ammonia.

6,104 ammonia exposures

The study identified:

6,104 single-product exposures involving ammonia-containing household cleaners in children younger than six.⁵

For 2,174 ammonia exposures with a known medical outcome, the researchers reported:

• 1,565 — no effect
• 582 — minor effect
• 22 — moderate effect
• 2 — major effect
• 0 — deaths

That means 24 ammonia exposures resulted in a moderate or major medical outcome, representing approximately 1.1% of the ammonia cases for which medical outcomes were known.⁵

These numbers are important for two reasons.

First, they demonstrate that accidental exposure actually occurs—thousands of times in a national poison-center dataset.

Second, they put the risk into appropriate perspective.

Most reported pediatric ammonia-cleaner exposures did not produce severe poisoning. Household ammonia products vary substantially in concentration, and a small accidental exposure to a diluted glass cleaner is very different from swallowing or inhaling concentrated ammonia.

But “most exposures are not severe” is not the same thing as “exposure does not occur.”

The data show both.

And for No Nines™, frequency of accidental exposure and severity if something goes wrong are both relevant formulation considerations.

Why Young Children Are Particularly Relevant

Young children interact with cleaning products differently from adults.

They explore by touching and mouthing objects. A spray bottle may look like something to squeeze. A wet floor may be crawled across. A container left temporarily within reach can become an exposure before an adult realizes it has happened.

ATSDR specifically advises families to keep ammonia-containing products out of children's reach and notes that children can be exposed to dilute ammonia solutions contained in household cleaners.¹⁰

The agency states that ammonia can injure the:

• eyes;
• skin;
• mouth;
• respiratory tract; and
• lungs.¹⁰

The effects depend strongly on concentration, amount, route, and duration of exposure.

That concentration dependence is important.

Poison-control guidance notes that small accidental exposures to dilute ammonia-containing household cleaners often result primarily in irritation, while concentrated products have substantially greater potential to produce burns and serious injury.¹¹

So the scientific concern is not that a child who briefly touches every ammonia-containing glass cleaner will suffer major poisoning.

The concern is that an ingredient with recognized irritating and corrosive properties is present in an environment where accidental exposures predictably occur.

What Happens When Ammonia Is Inhaled?

The respiratory tract is one of the primary targets of ammonia exposure.

NIOSH describes ammonia as a colorless gas with a pungent, suffocating odor and identifies the eyes, skin, and respiratory system among its primary target organs.²

Because ammonia is highly water soluble, inhaled ammonia readily interacts with the moist surfaces of the:

• nose;
• throat;
• eyes;
• trachea; and
• lungs.

Depending on concentration, exposure can cause irritation, coughing, burning, wheezing, airway narrowing, and difficulty breathing. At substantially higher exposures, lung injury and pulmonary edema can occur.¹⁻³

The CDC notes that survivors of substantial inhalational exposure can experience persistent respiratory effects, including chronic cough, reactive airway dysfunction, asthma-like symptoms, lung fibrosis, and ongoing respiratory irritation.¹

Again, dose matters.

The effects associated with an industrial ammonia release are not equivalent to ordinary use of a dilute household cleaner.

But the underlying exposure route remains relevant: when ammonia can be smelled during cleaning, ammonia molecules have entered the surrounding air.

Federal Exposure Limits Illustrate the Concentration-Dependent Hazard

Occupational limits provide useful context for understanding ammonia's inhalational toxicology.

NIOSH recommends:

• 25 ppm as an 8-hour time-weighted occupational exposure limit;
• 35 ppm as a short-term exposure limit; and
• 300 ppm as Immediately Dangerous to Life or Health, or IDLH.²

OSHA's permissible exposure limit is:

• 50 ppm averaged over an eight-hour workday.²

These are occupational air standards, not consumer-product limits.

Their significance here is that federal agencies have established specific airborne exposure thresholds for ammonia because inhaled concentration matters.

EPA's Acute Exposure Guideline Level program provides another perspective.

For a 60-minute exposure, EPA's final ammonia values are:

• AEGL-1: 30 ppm
• AEGL-2: 160 ppm
• AEGL-3: 1,100 ppm³

AEGL-1 corresponds to concentrations at which the general population, including susceptible individuals, could experience notable discomfort, irritation, or certain transient effects.

AEGL-2 addresses the possibility of serious or long-lasting effects or impaired ability to escape.

AEGL-3 addresses potentially life-threatening effects or death.

These guidelines concern unusual acute airborne exposures rather than normal household cleaning.

But they demonstrate a fundamental toxicological principle: the hazard from ammonia changes substantially as airborne concentration increases.

The Odor Is the Chemical in the Air

Ammonia's sharp smell is sometimes treated as simply an unpleasant characteristic of traditional cleaning products.

Chemically, it means something more.

Because ammonia is volatile, its characteristic odor results when gaseous ammonia reaches the nose.

In other words, the smell is evidence that ammonia has left the product and entered the surrounding air.

A fragrance can cover or alter the perception of an unpleasant cleaner odor.

It cannot prevent the underlying volatile compound from being present.

No Nines™ does not believe a formulation should require added fragrance simply to make an inherently pungent cleaning chemistry more acceptable.

We formulate without ammonia—and without synthetic fragrance.

Eye and Skin Exposure

Ammonia exposure is not limited to inhalation.

Aqueous ammonia is alkaline, and direct contact can injure the eyes and skin depending on concentration and exposure time.¹˒²˒¹⁰

Eye exposure is particularly important because ammonia dissolves readily into the moisture on the eye surface.

CDC describes higher-level ammonia exposure as capable of producing eye burns and temporary or permanent visual injury.¹

ATSDR similarly notes that concentrated ammonia solutions can burn the eyes, skin, mouth, throat, and stomach.¹⁰

This is one reason product concentration matters so much.

A dilute consumer cleaner and concentrated industrial ammonia are not toxicologically equivalent.

But dilution changes the degree of hazard.

It does not change ammonia into a different chemical.

Pets Have Different Exposure Pathways

People generally do not deliberately walk barefoot across a freshly sprayed floor and then lick their feet.

Pets do.

That creates exposure pathways particularly relevant to household cleaning products.

A dog or cat may:

• walk across a wet floor;
• step into a spill;
• lick cleaner from its paws;
• groom contaminated fur;
• lick a cleaned surface;
• investigate a mop bucket;
• chew or puncture a container; or
• remain close to the floor while volatile chemicals are being used.

Veterinary toxicology references identify ammonia among acid and alkali cleaning chemicals capable of causing skin and eye burns, respiratory irritation, coughing, and lung injury at sufficiently high exposure.⁹

Pets can also turn one exposure route into another.

A product contacting the paws or coat can subsequently become an oral exposure during grooming.

This is an important distinction when evaluating cleaning chemistry intended for homes occupied by animals.

What Do Pet Poison-Control Numbers Show?

Nationally published veterinary poison statistics generally combine household products into categories rather than reporting ammonia separately.

ASPCA Poison Control reported that in 2025 it received calls concerning more than 376,000 items to which pets had been exposed.¹²

Household products accounted for 6.4% of reported exposures, with cleaners and paints making up a substantial portion of that category.¹²

The published ASPCA annual statistics do not provide a separate national count for ammonia exposures.

That distinction matters.

We can document that household products are a recurring source of pet poison-control calls, and veterinary toxicology references identify ammonia as a cleaning-product hazard.

However, we cannot accurately claim that a specific number of those national pet cases were caused by ammonia because the ammonia-specific data are not recorded.

Why Pet Exposure Can Matter Even When a Product Is Not Swallowed From the Bottle

An animal does not need to drink a bottle of cleaner to encounter the chemistry.

Veterinary guidance emphasizes that cleaners can expose animals through:

• ingestion;
• eye contact;
• skin contact; and
• inhalation.⁹˒¹³

Alkaline chemicals can produce local tissue injury at the site of contact. Veterinary references describe possible injury to the skin, cornea, oral cavity, esophagus, stomach, and respiratory tract following significant corrosive exposures.¹³

Birds warrant additional caution because veterinary poison-control guidance recognizes their particular sensitivity to airborne fumes from household products.¹⁴

Again, this does not mean normal use of every diluted ammonia-containing cleaner will poison an animal.

It means that ingredient selection changes the consequences of accidental exposure, and animals have several realistic ways of encountering cleaning products after application.

Bleach + Ammonia: A Preventable Chemical Reaction

Perhaps the most significant misuse hazard associated with ammonia-containing cleaners is the reaction with chlorine bleach.

Ammonia should never be mixed with sodium hypochlorite bleach.

When hypochlorite reacts with ammonia, chloramine compounds can form and enter the air. Exposure can cause intense irritation of the eyes and respiratory tract, coughing, wheezing, chest discomfort, and potentially serious lung injury.⁶

This is not simply a warning based on theoretical chemistry.

In 1986, physicians Reisz and Gammon reported three cases of life-threatening toxic pneumonitis caused by people mixing household ammonia and chlorine bleach.⁶

All three patients required prolonged hospitalization.

The authors concluded that exposure to household ammonia-bleach mixtures could represent an underrecognized cause of acute chemical pneumonitis.⁶

Veterinary references give the same warning for animals: mixing hypochlorite bleach with ammonia can generate highly toxic chloramine gas and may cause acute respiratory distress or delayed pulmonary edema.¹⁵

This is exactly the type of foreseeable misuse contemplated by the No Nines™ Standard™.

Two products may each look like ordinary household cleaners.

But combining them can create an entirely different chemical exposure.

Repeated Cleaning Exposure and Respiratory Health

Professional cleaning workers provide an important population for studying repeated exposure to cleaning chemicals because they use these products more frequently than most household consumers.

A 2011 study evaluated 917 employees from 37 cleaning companies.⁷

Researchers examined cleaning-product use and respiratory symptoms.

Use of ammonia was among the cleaning-product exposures associated with a higher asthma symptom score.⁷

This was an observational study and does not establish that ammonia alone caused each worker's respiratory symptoms. Cleaning workers commonly encounter mixtures of products and multiple irritants.

But the findings are consistent with the established respiratory-irritant properties of ammonia.

A subsequent systematic review examined 24 epidemiological studies of asthma and rhinitis among cleaning workers.⁸

Increased risk of asthma or rhinitis was reported in 79% of the studies reviewed.

Specific exposures identified across the literature included:

• cleaning sprays;
• bleach;
• ammonia;
• mixing cleaning products; and
• particular cleaning tasks.⁸

The authors identified substitution of cleaning sprays, bleach, and ammonia among potential occupational prevention strategies.⁸

That does not mean occasional household use creates the same exposure experienced by a professional cleaner.

It does mean that repeated inhalational exposure to irritating cleaning chemistry has been sufficiently documented to warrant consideration when designing products intended for repeated use.

Environmental Toxicity

Ammonia also has a well-established aquatic toxicology.

The U.S. Environmental Protection Agency has developed national recommended freshwater aquatic-life criteria specifically for ammonia because sufficiently high concentrations can directly harm aquatic organisms.¹⁶

EPA explains that when ammonia concentrations become high enough, aquatic organisms may be unable to excrete ammonia sufficiently, allowing toxic concentrations to accumulate in tissues and blood.

Potential consequences include impaired growth, reproduction, survival, and death.¹⁶

Ammonia toxicity in water depends strongly on factors including pH and temperature.

EPA's 2013 freshwater criteria, at pH 7 and 20°C, recommend:

• an acute criterion of 17 mg total ammonia nitrogen/L as a one-hour average; and
• a chronic criterion of 1.9 mg total ammonia nitrogen/L as a 30-day rolling average.¹⁶

Those are environmental water-quality criteria—not concentrations for consumer cleaning products.

And use of a single household ammonia cleaner does not mean that an aquatic ecosystem will be harmed.

The relevance is broader:

ammonia is not environmentally inert.

Its environmental concentration matters just as its airborne concentration matters.

Why This Matters for Everyday Cleaning

A chemical can be effective and still be unnecessary.

That distinction is central to the No Nines™ Standard™.

Ammonia clearly performs useful cleaning functions.

But its complete exposure profile includes more than whether it removes grease or leaves glass streak-free.

Ammonia:

can volatilize from a cleaning solution into indoor air;

is a recognized eye and respiratory irritant;

can produce corrosive injury at sufficiently high concentrations;

was involved in 6,104 documented unintentional household-cleaner exposures among U.S. children under six in a 2016–2023 national poison-center dataset;

has been associated with respiratory symptoms in occupational cleaning research;

can expose pets through paws, fur, grooming, inhalation, spills, and wet surfaces;

can react with chlorine bleach to generate toxic chloramine gases; and

has recognized aquatic toxicity at sufficiently elevated environmental concentrations.

None of this means that every use of an ammonia-containing household product causes injury.

The poison-center data themselves demonstrate that most reported childhood ammonia exposures with known outcomes were either asymptomatic or minor.

That is worth stating clearly.

But the No Nines™ Standard™ asks a different question.

If an ingredient creates an exposure pathway, if accidental exposures occur in real homes, if misuse can produce substantially greater hazards, and if the intended cleaning function can be achieved using different chemistry—

why introduce that exposure when we do not need to?

For No Nines™, we don't.

That is why ammonia is one of the ingredient categories we leave out.

Effective chemistry doesn't require unnecessary exposure.

Published Sources & Further Reading

1. Centers for Disease Control and Prevention (CDC), National Center for Environmental Health. Ammonia: Chemical Fact Sheet. Chemical Emergencies. Originally published September 16, 2024; updated June 10, 2026; reviewed June 11, 2026. Describes inhalational, ocular, dermal, and ingestion exposure; acute and chronic respiratory effects; high-concentration injury; and household-cleaner mixing hazards.

2. National Institute for Occupational Safety and Health (NIOSH). NIOSH Pocket Guide to Chemical Hazards: Ammonia. CAS No. 7664-41-7. NIOSH REL: 25 ppm TWA; 35 ppm STEL. IDLH: 300 ppm. Current OSHA PEL listed as 50 ppm TWA. NIOSH Pocket Guide chemical entry; associated with NIOSH Publication No. 2005-149.

3. U.S. Environmental Protection Agency. Ammonia Results — Acute Exposure Guideline Levels (AEGL) Program. CAS No. 7664-41-7. Final AEGL values. For a 60-minute exposure: AEGL-1, 30 ppm; AEGL-2, 160 ppm; AEGL-3, 1,100 ppm. See also National Research Council, Acute Exposure Guideline Levels for Selected Airborne Chemicals, Volume 6. Washington, DC: National Academies Press; 2008. DOI: 10.17226/12018. PMID: 25032325.

4. Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Ammonia. U.S. Department of Health and Human Services, Public Health Service; September 2004. Includes toxicokinetics, inhalation and ingestion effects, pediatric exposure information, environmental fate, and public-health guidance.

5. Kendric KJ, Durrani TS. Trends in pediatric household cleaning product exposures before and during the COVID-19 pandemic: a national poison data system analysis (2016–2023). BMC Pediatrics. 2026;26:658. Published May 21, 2026. DOI: 10.1186/s12887-026-07010-2. PMID: 42168921. National Poison Data System analysis of unintentional household-cleaner exposures in children younger than six. Reports 6,104 ammonia exposures, including 22 moderate and two major outcomes among ammonia exposures with known outcomes.

6. Reisz GR, Gammon RS. Toxic pneumonitis from mixing household cleaners. Chest. 1986;89(1):49–52. DOI: 10.1378/chest.89.1.49. PMID: 3940787. Reports three cases of life-threatening toxic pneumonitis after exposure to mixtures of household ammonia and sodium hypochlorite bleach.

7. Vizcaya D, Mirabelli MC, Antó JM, Orriols R, Burgos F, Arjona L, Zock JP. A workforce-based study of occupational exposures and asthma symptoms in cleaning workers. Occupational and Environmental Medicine. 2011;68(12):914–919. DOI: 10.1136/oem.2010.063271. PMID: 21558474. Study of 917 employees from 37 cleaning companies; ammonia use was among cleaning-product exposures associated with asthma symptom score.

8. Folletti I, Zock JP, Moscato G, Siracusa A. Asthma and rhinitis in cleaning workers: a systematic review of epidemiological studies. Journal of Asthma. 2014;51(1):18–28. DOI: 10.3109/02770903.2013.833217. PMID: 23931651. Systematic review of 24 epidemiological studies; reports increased asthma or rhinitis risk in 79% of included studies and identifies ammonia, bleach, cleaning sprays, product mixing, and specific cleaning tasks among relevant exposures.

9. Merck Veterinary Manual. Cleaners and Disinfectants as a Veterinary Workplace Hazard. Current veterinary toxicology reference. Identifies acids and alkalis, including ammonia, as cleaning chemicals associated with skin and eye burns, respiratory irritation, coughing, and lung injury at high exposure.

10. Agency for Toxic Substances and Disease Registry (ATSDR). Ammonia — ToxFAQs™. U.S. Department of Health and Human Services. Companion consumer summary to the Toxicological Profile for Ammonia. Discusses household-cleaner exposure, pediatric exposure, ingestion of concentrated ammonia solutions, eye injury, respiratory effects, and recommendations for reducing childhood exposure.

11. National Capital Poison Center. Ammonia: History, Usage, and Safety. Poison Control. Consumer toxicology guidance addressing household ammonia, childhood exposure to ammonia-containing glass cleaners, concentration-dependent toxicity, ocular and oral exposure, and bleach-ammonia mixing.

12. American Society for the Prevention of Cruelty to Animals (ASPCA), Poison Control. The Top 10 Toxins of 2025. Published March 15, 2026. Reports more than 376,000 pet exposure items handled by ASPCA Poison Control during 2025; household products accounted for 6.4% of exposures, with cleaners and paints representing a substantial portion of the category.

13. Gwaltney-Brant SM. Toxicoses From Corrosive Agents in Animals. Merck Veterinary Manual. Full review March 2025. Peer reviewed by Brutlag A, DVM, DABT, DABVT. Describes alkaline and acidic corrosive injury affecting skin, cornea, oral cavity, esophagus, stomach, and other exposed tissues in animals.

14. American Society for the Prevention of Cruelty to Animals (ASPCA), Animal Poison Control Center. Poisonous Household Products. Current veterinary poison-control guidance. Discusses cleaning-product exposures in dogs and cats and notes particular concern regarding airborne household-product exposure in birds.

15. Merck Veterinary Manual. Toxicoses From Household Cleaners and Personal Care Products in Animals. Current veterinary toxicology reference. Notes that mixing hypochlorite bleach and ammonia produces highly toxic chloramine gas capable of producing acute respiratory distress or delayed pulmonary edema.

16. U.S. Environmental Protection Agency, Office of Water, Office of Science and Technology. Aquatic Life Ambient Water Quality Criteria for Ammonia — Freshwater 2013. EPA-822-R-13-001, April 2013. See also EPA Fact Sheet 820-F-13-013, August 2013. Establishes national recommended freshwater criteria addressing acute and chronic ammonia toxicity, including sensitive freshwater mussels and snails.