We are all using cleaning products. They encompass a large variety of household chemicals including laundry detergents, dishwashing detergents, softeners, toilet cleaners, glass cleaners, polishers - to name just a few. Certainly, cleaning products are needed, but how safe are they?
The question is triggered by several research articles pointing out the presence of toxic or hazardous chemicals in many cleaning products (Zarogianni et al., 2017; Steinmann et al., 2011; Steinmann, 2009; Kwon et al., 2008; Rastogi et al., 2001). With this in mind, we have decided to research this matter further and provide a synthesis of our findings and hints for reducing any possible associated risks of human exposure to cleaning products.
Cleaning products are made up of complex mixtures of chemicals, some of which may pose serious health risks. Apart from the detergent components (such as surfactants), many chemicals may be added to a cleaning product to provide a nice smell or neutralize bad smells. These are fragrance compounds. According to Rastogi et al (2001), approximately 2500 substances are used in fragrances, which may contain from 10 to more than 300 different chemical compounds. While the number of individual chemicals in cleaning product fragrances vary, even the so-called "green" products or products with no smell were found to contain fragrance chemicals (Zarogianni et al., 2017). So, the lack of smell in a cleaning product does not necessarily mean it contains no fragrance chemicals. The fragrance chemicals may still be present in order to eliminate bad smells.
A selective (non-comprehensive) list of fragrance chemicals reported to be present in cleaning products is presented in Table 1. The chemicals from this table were selected from those reported in more than one cleaning product and which may raise a potential health issue.
One may wonder that such a large number of chemicals potentially present in cleaning products would certainly attract attention on the product label. However, U.S. regulations do not necessarily require disclosure of all ingredients in a consumer product, or of any ingredients in a mixture called "fragrance." In addition, fragrance formulas are considered trade secrets and components that make up the fragrance portion of the product are not revealed on labels. Therefore, the fragrance chemicals may not be listed on the product label. This was recently found to be the case in other countries such as Greece - with most fragrance chemicals found to be lacking from tested product labels (Zarogianni et al., 2017).
Disclosed or not, some of the fragrance chemicals may be harmful to humans and are classified as toxic or hazardous under U.S. federal laws (see examples in Table 1). Many of the chemicals used in fragrances are synthetic compounds derived from petroleum. They include benzene derivatives, aldehydes and many other known toxics and sensitizers capable of causing cancer, birth defects, central nervous system disorders and allergic reactions.According to Bridges (2002): Fragrance is increasingly cited as a trigger in health conditions such as asthma, allergies and migraine headaches. In addition, some fragrance materials have been found to accumulate in adipose tissue and are present in breast milk. Other materials are suspected of being hormone disruptors.
Consumers may be exposed to these toxic chemicals in several ways, particularly through direct skin contact and by breathing the vapors of these chemicals released in the air. Let us consider each of these potential exposure pathways. The first one involves the use of the products with direct skin contact possibly occurring each time the product is used. The second pathway certainly happens when the products are used, but it can also happen in between uses - depending on where and how the products are stored and how much of the indoor air gets exchanged/replaced periodically. Therefore, in general, the potential inhalation pathway may become more important than skin exposure.
The studies to date were focused on emitted compounds (e.g., Steinmann et al., 2011; Steinmann, 2009) or fragrance ingredients, rather than human exposures and effects from those compounds, therefore possible risks to human health from product use remain largely unknown.
The studies tested various cleaning products, including laundry detergents, softeners (liquid and fabric), dishwasher detergent, toilet cleaners, glass cleaners, and general purpose cleaners. Hand sanitizers, shampoo, and air fresheners have also been tested. Both green and non-green products have been tested, as well as professional and non-professional products.
More than 150 volatile organic compounds (VOCs) were identified through testing (as emitted in the air or extracted from the cleaning product itself), with an average of 17 VOCs emitted per tested product. Most of identified emitted VOCs are fragrance ingredients, while few may be byproducts from the manufacturing process (e.g., 1,4-dioxane).
A safety assessment of fragrance materials is performed by the industry (e.g., the Research Institute for Fragrance Materials) and has been described in the literature (Bickers et al., 2003). This process includes a systematic prioritization of data generation and analysis, consideration of exposure and critical analysis of the quality of the available information. The analysis groups many individual ingredients into classes based on chemical structures. However, toxicological studies addressing specific use or misuse of cleaning products focusing on emitted individual VOCs in the breathing space seem to be lacking. While not quantified, the potential health risk associated with cleaning products has been pointed out in the literature. For example, according to Nazaroff and Weschler (2004): "The inhalation intake of airborne organic compounds from cleaning product use was estimated to be of the order of 10 mg d-1 person-1 in California." Also, according to the same authors: "there are strong parallels between exposure from cleaning product/air freshener use and the broader concerns of air pollutant exposures from indoor sources. Important data gaps remain to be filled before a fully satisfactory understanding can be gained of inhalation exposures associated with cleaning products and air fresheners. Key data needs include better information on product composition, human factors that affect use and exposure, mechanistic and kinetic details for reactions involving important constituents, and the potential health effects of the secondary pollutants."
While people may get exposed to harmful chemicals potentially present in cleaning products, this may not necessarily translate in any type of harm. As is well known, the dose makes the poison, or, in other words, the exposure needs to reach a certain level to trigger any health risk. Both the duration of the exposure (e.g., the time toxic vapors are breathed in) and the amount of chemicals to which people are exposed (e.g. the concentration of the toxic vapors from the breathing area) contribute to the potential risk.
While, to our knowledge, no studies have addressed such potential health risks, here are some tips that should help minimize any potential exposure to toxic fragrance chemicals in cleaning products:
We don't know for sure if regular use is entirely safe. We do know that, in large quantities, many of these products are harmful to us and the environment. Even in lower doses, fragrance compounds may pose emerging health and environmental concerns. Until more detailed studies dealing with potential exposure risks from cleaning products become available, potential risks exist when cleaning products are used. Consumers and companies alike need to push for such studies. However, using and storing cleaning products wisely (see the tips provided in this article) could minimize or eliminate such potential risks, while you can still enjoy the benefits that make cleaning products so popular.
Bickers, D.R., Calow, P., Greim, H.A., Hanifin, J.M., Rogers, A.E., Saurat, J.H., et al. 2003. The safety assessment of fragrance materials. Regul Toxicol Pharmacol. 2003;37(2):218-273
Bridges B. 2002. Fragrance: emerging health and environmental concerns. Flavour Fragr J. 2002; 17(5):361-371.
Kwon, K.D., Jo, W.K., Lim, H.J., Jeong, W.S. 2008. Volatile pollutants emitted from selected liquid household products. Environ Sci Pollut Res Int. 2008; 15(6):521-526.
Nazaroff, W.W., and Weschler, C.J. 2004. Cleaning products and air fresheners: exposure to primary and secondary air pollutants. Atmospheric Environment 38(2004): 2841-2865.
Rastogi, S.C., Heydorn, S., Johansen, J.D., Basketter, D.A. 2001. Fragrance chemicals in domestic and occupational products. Contact Dermatitis. 2001; 45(4):221-225
Steinemann, A.C. 2009. Fragranced consumer products and undisclosed ingredients. Environ Impact Assess Rev. 2009; 29(1):32-38.
Steinemann, A.C., MacGrego,r I.C., Gordon, S.M., Gallagher, L.G., Davis, A.L., Ribeiro, D.S., Wallace, L.A. 2011. Fragranced consumer products: chemicals emitted, ingredients unlisted. Environ Impact Assess Rev. 2011; 31(3):328-333.
Zarogianni, A.-M., Loupa, G., Rapsomanikis, S. 2017. A comparison of fragrance ingredients in green and non-green detergents. Environmental Forensics 18 (2), in press.
Table 1. Summary of Identified Cleaning Products, Associated Fragrance Ingredients and Other Compounds of Potential Environmental or Health Risks