Human health risk assessment of chloroxylenol in liquid hand soap and dishwashing soap used by consumers and health-care professionals
Section snippets
Background
Chloroxylenol (4-chloro-3, 5-dimethylphenol or PCMX; CAS No. 88-04-0, see Fig. 1) is an antimicrobial chemical with a long history of safe use in topical antiseptic drug products for over-the-counter human use (FDA, 2013, FDA, 1994), and for pesticide use (EPA, 1994, EPA, 2009a, EPA, 2009b). A human health risk assessment was conducted to evaluate the safety of chloroxylenol used as an active ingredient in rinse-off liquid antimicrobial hand soaps and dish soaps by consumer (adults and
Methods
This quantitative human health risk assessment includes (1) a hazard assessment to determine whether toxicity data for chloroxylenol are sufficient and derivation of no observed adverse effect levels (NOAELs), (2) an exposure assessment for consumer and health-care uses of liquid soaps containing chloroxylenol, and (3) calculation of the margin of exposure (MOE) for different product use scenarios, i.e., the ratio of the experimental NOAEL to the estimated human exposure level for each of the
Hazard assessment
A hazard assessment was conducted for chloroxylenol to evaluate all available toxicology data and consider the studies that could be used to establish a no observed adverse effect level (NOAEL) for chloroxylenol. Relevant reviews providing data on toxicity of chloroxylenol include the following: the Environmental Protection Agency (EPA) hazard and exposure evaluations for pesticide use (EPA, 1994, EPA, 2009a), the FDA (2013) analysis and request for data, a “white paper” risk assessment
Acute toxicity studies
Available acute exposure studies, lethality or LD50 studies, indicate low acute toxicity of chloroxylenol and provide some useful information on organ systems affected at such lethal doses. A summary of the LD50 and lethality data was completed in 1986 by Guess and Bruch, and similar summaries appear in the Handbook of Disinfectants and Antiseptics (Bruch, 1996) and the EPA Reregistration Eligibility Decision (RED) for chloroxylenol (EPA, 1994) (Table 1).
As presented in Table 1, LD50 values
Selection of NOAELS for margin of exposure analysis
While limitations exist in the toxicological database for chloroxylenol, the existing dataset indicate lack of genotoxicity and carcinogenicity and low acute, systemic and DART toxicity. Overall the existing toxicity data are sufficient for conducting a quantitative risk assessment for consumer and health-care worker exposure to chloroxylenol in hand or dish soap. The data used include the NOAEL of 100 mg/kg-day for maternal toxicity identified in the study by Siglin (1991) supported by the
Exposure assessment and margin of exposure (MOE) estimates
Procedures described by Sanderson et al. (2006), which use algorithms, and methods identified by USEPA., 1989, EPA, 2011 together with inputs from the EPA Exposure Factors Handbook (EPA, 2011) were used to estimate exposure to chloroxylenol resulting from three exposure scenarios: one related to the use of antimicrobial hand soap and two related to the use of dish washing with products containing chloroxylenol. In each case, “high” and “low” exposure scenarios are considered that differ in the
Discussion
Chloroxylenol has a long history of safe use in topical antiseptic drug products for over-the-counter human use and in hard surface disinfectant use (regulated as a pesticide). This human health risk assessment was conducted to evaluate the adequacy of existing toxicological data and to evaluate human risk for consumer and health-care worker use of rinsed off hand soap and dish soap in response to concerns raised within the FDA Proposed Rules on topical antimicrobial drug products for OTC human
Conclusions
The existing toxicity data for chloroxylenol have limitations, but taken together the data are adequate for evaluation of the risks associated with consumer and health-care exposure to chloroxylenol in hand soap or dish soap. The NOAEL of 100 mg/kg-day for maternal toxicity from Siglin (1991) supported by Noda et al. (1983) to address DART and a NOAEL of 18 mg/kg-day for chronic systemic exposure from Momma et al. (1988) represent a health-protective means to evaluate risks for this use.
Acknowledgements
The authors gratefully acknowledge funding for this work provided by the American Cleaning Institute.
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2022, HeliyonCitation Excerpt :Data depicts that out of 146 respondents, 4.35% and 2.48% of respondents clean foods by using detergent or soap and using bleaching powder. However, it has been reported that cleaning food with any soap is harmful to health [33]. Additionally, precaution should be taken during washing foods because cross contaminations can occur [34] that can be a double threat to health in this pandemic situation [35, 36].