Introduction

Biocides are non-agricultural pesticides used to control, eliminate, inhibit, detoxify, or prevent harmful organisms in ways other than mere physical and mechanical actions. They include active materials such as microorganisms and substances that affect harmful organisms. A product containing one or more of these active substances is called a biocidal product.

Benzalkonium chloride (BAC) was classed as a Category III antiseptic active ingredient by the US FDA because of a lack of adequate safety data for its use as both a health care antiseptic and consumer antiseptic product [1]. BAC is a mixture of alkylbenzyl dimethylammonium chlorides of various even-numbered alkyl chain lengths (C8-C18) [2] and it is commonly used as disinfectants in food, industrial and domestic areas [3]. 

Figure 1 Characteristics of Benzalkonium Chloride

Applications

BAC is an active ingredient in several consumer products, including pharmaceutical products such as eye, ear, and nasal drops or sprays, as a preservative; personal care products such as hand sanitizers, wet wipes, shampoos, deodorants, and cosmetics; skin antiseptics, such as Bactine and Dettol; throat lozenges [4] and mouthwashes, as a biocide; spermicidal creams; over-the-counter single-application treatments for herpes, cold-sores, and fever blisters, such as RELEEV and Viroxyn; burn and ulcer treatments; spray disinfectants for hard surface sanitization; cleaners for floor and hard surfaces as a disinfectant, such as Lysol; algaecides for clearing algae, moss, and lichens from paths, roof tiles, swimming pools, and masonry. BAC is also used in several non-consumer processes and products; for example, as an active ingredient in surgical disinfection.

A comprehensive list of uses includes industrial applications [5]. Benzalkonium chloride is a frequently used preservative in eye drops; typical concentrations range from 0.004 to 0.01%. Higher concentrations can be caustic [6] and can cause irreversible damage to the corneal endothelium [7]. Occupational exposure to BAC has been linked to the development of asthma [8]. Furthermore, BAC has been commonly used as a pharmaceutical preservative and antimicrobial since the 1940s. Therefore, there is a need for studies to evaluate the effects of occupational exposure to BAC in the form of aerosols, considering the associated health risks.

[3]Lavorgna M, Russo C, D'Abrosca B, Parrella A, Isidori M. Toxicity and genotoxicity of the quaternary ammonium compound benzalkonium chloride (BAC) using Daphnia magna and Ceriodaphnia dubia as model systems. Environ Pollut. 2016;210:34–9.

[4]Bradosol. Archived from the original on 2014-10-12. Retrieved 2013-05-20.

[5]Ash M, Ash I. Handbook of Preservatives: Synapse Info Resources; 2004. p. 286. ISBN 978-1-890-59566-1.

[6]Nelson L, Goldfrank L. Goldfrank's Toxicologic Emergencies. 9th ed: McGraw-Hill Medical; 2011. p. 803. ISBN 978-1-890-59566-1.

[7]Baudouin C, Creuzot-Garcher C, Hoang-Xuan, T. Inflammatory diseases of the conjunctiva (1, illustrated ed.). Thieme; 2001. p. 141. ISBN 978-3-131-25871-7.

[8]Malo J, Chan-Yeung M, Bernstein DI. Asthma in the Workplace (4, illustrated, revised ed.). CRC Press; 2013. p. 198.