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Short answer: Benzalkonium chloride is a quaternary ammonium compound (a “quat”) that appears in two different regulatory settings. As a surface disinfectant ingredient, quats are used for routine cleaning of noncritical surfaces under EPA registration. As an over-the-counter health care antiseptic ingredient, FDA has deferred a final decision on it since 2017. The CDC does not rate quats as sporicidal, and says they are generally not tuberculocidal or virucidal against nonenveloped viruses.
General information only, drawn from CDC and FDA documents. It is not medical advice and not a recommendation to use or avoid any product.
Definition and scope
Benzalkonium chloride (BAC) belongs to the quaternary ammonium compounds. The CDC’s Guideline for Disinfection and Sterilization in Healthcare Facilities describes the quat class as having a bactericidal mechanism of “inactivation of energy-producing enzymes, denaturation of essential cell proteins,” and disruption of the cell membrane. For the wider family and how it differs from other chemistries, see CASRAI’s guide to quaternary ammonium compounds and the overview of types of disinfectants.
The key point for supply and infection-control staff is that the same ingredient name shows up under two different rule sets, which are easy to confuse: surface disinfectants (EPA-registered products) and skin antiseptics (FDA’s over-the-counter antiseptic rulemaking).
How it is used in practice
The CDC states that quats are commonly used for routine cleaning of noncritical surfaces, and that it is appropriate to use an EPA-registered quat to disinfect medical equipment that contacts intact skin, such as blood pressure cuffs. The CDC also describes quats as good cleaning agents.
The CDC lists several practical limits that apply to quat-based products in general:
- Spectrum: quats are “not sporicidal and generally not tuberculocidal or virucidal against hydrophilic (nonenveloped) viruses,” and the CDC notes that their poor mycobactericidal activity has been demonstrated.
- Hard water: hard water can reduce effectiveness through insoluble precipitates. The CDC adds that newer twin-chain quats are purported to remain active in hard water and to tolerate anionic residues.
- Absorbent materials: cotton and gauze pads absorb the active ingredients. In one study cited by the CDC, the concentration of quat released was about 40-50% lower after one hour with cotton rags or cellulose-based wipers in an open-bucket system, compared with nonwoven spunlace wipers in a closed-bucket system.
- Contaminated solutions: the CDC reports that health-care-associated infections have been traced to contaminated quaternary ammonium solutions, and that gram-negative bacteria can survive or grow in them.
Regulatory status: what “deferred” means
In a final rule published in the Federal Register on December 20, 2017 (82 FR 60474, Docket FDA-2015-N-0101), FDA addressed over-the-counter antiseptics for health care professionals: hand washes and rubs, surgical hand scrubs and rubs, and patient preoperative and preinjection skin preparations. The rule took effect December 20, 2018. FDA found 24 ingredients not generally recognized as safe and effective (GRAS/GRAE) for these uses, and deferred action on six: benzalkonium chloride, benzethonium chloride, chloroxylenol, alcohol (ethanol), isopropyl alcohol and povidone-iodine.
FDA wrote that it “does not make a GRAS/GRAE determination in this final rule for these six active ingredients.” Deferral therefore means the question is open: neither an endorsement nor an exclusion. FDA said the status will be addressed after ongoing studies fill safety and effectiveness data gaps, or at a later date if those studies are not completed. The earlier 2016 consumer antiseptic wash rule (81 FR 61106, September 6, 2016) likewise deferred benzalkonium chloride, benzethonium chloride and chloroxylenol for consumer wash products, as described in the 2017 document. For the broader antiseptic picture, see what is an antiseptic.
Resistance: the evidence FDA cites
FDA asked for resistance testing for three of the six deferred ingredients: benzalkonium chloride, benzethonium chloride and chloroxylenol. It was not requested for the alcohols or povidone-iodine. FDA also said additional studies on cross-resistance to antibiotics are needed for those three. The agency summarised evidence that points in different directions:
- FDA wrote that laboratory resistance development “is very common for some active ingredients, such as benzethonium and benzalkonium chloride,” while cautioning that laboratory observations are not necessarily replicated in real-world settings.
- Among clinical isolates, FDA described “strong evidence of antiseptic resistance” to benzethonium and benzalkonium chloride, with qacA/B and qacE genes found in 83 percent and 73 percent of isolates tested and correlated with reduced susceptibility.
- In contrast, two studies by Kawamura-Sato and colleagues found BAC minimum inhibitory concentrations for 283 clinical isolates “well within” the in-use concentration.
Related ingredients, as FDA groups them
| Question | What the source says | Source |
|---|---|---|
| Which ingredients share BAC’s FDA deferral? | Benzethonium chloride, chloroxylenol, alcohol, isopropyl alcohol, povidone-iodine | FDA, 82 FR 60474 |
| Which of these were asked for resistance testing? | Benzalkonium chloride, benzethonium chloride, chloroxylenol | FDA, 82 FR 60474 |
| Is it sporicidal? | No (quats as a class) | CDC, Chemical Disinfectants |
| Reliable against nonenveloped viruses and mycobacteria? | Generally not tuberculocidal or virucidal against nonenveloped viruses | CDC, Chemical Disinfectants |
| Affected by cotton or gauze? | Yes, these materials absorb the active ingredients | CDC, Chemical Disinfectants |
| Hard-water effect? | Can reduce effectiveness; twin-chain quats purported to tolerate it | CDC, Chemical Disinfectants |
Where it matters for labs, clinics and supply decisions
A source-based checklist for anyone reading a product label or safety data sheet that lists benzalkonium chloride:
- Which rulebook applies? A surface product is an EPA-registered disinfectant question; a skin product is an FDA antiseptic question. FDA’s deferral covers antiseptic use, not surface disinfectants. Related reading: EPA List Q.
- Which organisms matter? Quats are not sporicidal and generally not tuberculocidal or virucidal against nonenveloped viruses (CDC). See virucidal.
- What carries the product? Cotton and gauze absorb the active ingredient, so the concentration delivered can fall.
- How is the solution stored and refilled? The CDC links contaminated quat solutions to health-care-associated infections.
- Who handles it? The CDC notes a few case reports of occupational asthma from benzalkonium chloride exposure.
For wider selection factors such as contact time and material compatibility, see surface disinfectant selection.
Common misunderstandings
- “FDA deferred it, so it was banned.” No. Deferral is not a ruling either way.
- “A quat disinfectant covers every pathogen.” The CDC says it is not sporicidal and generally not tuberculocidal or virucidal against nonenveloped viruses.
- “Laboratory resistance proves clinical failure.” FDA itself says laboratory observations are not necessarily replicated in the real world, and cites isolate studies pointing both ways.
FAQ
What is benzalkonium chloride?
A quaternary ammonium compound used as a disinfectant and antiseptic ingredient. The CDC covers quats as surface disinfectants; FDA has deferred a decision on its use in health care antiseptics.
Is benzalkonium chloride safe?
This guide cannot give individual safety advice. Two documented points: the CDC reports a few case reports of occupational asthma after exposure, and FDA has not determined whether it is generally recognized as safe and effective as an over-the-counter health care antiseptic, pending further data. Follow the product label and safety data sheet, and ask a clinician or occupational health professional about personal exposure.
Does benzalkonium chloride kill all germs?
No. The CDC says quats are not sporicidal and generally not tuberculocidal or virucidal against nonenveloped viruses.
Can bacteria become resistant to it?
FDA reports that laboratory resistance development is common and that resistance genes were found in clinical isolates, while other studies found susceptibility within in-use concentrations. FDA has asked for further resistance and cross-resistance studies.
Sources
- CDC, Chemical Disinfectants, from the Guideline for Disinfection and Sterilization in Healthcare Facilities (2008; page dated 2023-11-28). Date checked: 2026-10-30.
- FDA, Safety and Effectiveness of Health Care Antiseptics; Topical Antimicrobial Drug Products for Over-the-Counter Human Use, 82 FR 60474 (December 20, 2017), Docket FDA-2015-N-0101. Date checked: 2026-10-30.
