A Comparative Human Health Risk Assessment of p-Dichlorobenzene-Based Toilet Rimblock Products Versus Fragrance/Surfactant-Based Alternatives

Abstract

A comparison of the human health risk to consumers using one of two types of toilet rimblock products, either a p-dichlorobenzene-based rimblock or two newer fragrance/surfactant-based alternatives, was conducted. Rimblock products are designed for global use by consumers worldwide and function by releasing volatile compounds into indoor air with subsequent exposure presumed to be mainly by inhalation of indoor air. Using the THERdbASE exposure model and experimentally determined emission data, indoor air concentrations and daily intake values were determined for both types of rimblock products. Modeled exposure concentrations from a representative p-dichlorobenzene rimblock product are an order of magnitude higher than those from the alternative rimblock products due to its nearly pure composition and high sublimation rate. Lifetime exposure to p-dichlorobenzene or the subset of fragrance components with available RfD values is not expected to lead to non-cancer-based adverse health effects based on the exposure concentrations estimated using the THERdbASE model. A similar comparison of cancer-based effects was not possible as insufficient data were available for the fragrance components.

This submission was supported by funding from S. C. Johnson & Son, Inc.

Notes

Agency for Toxic Substances and Disease Registry. 1998. Toxicological profile for 1,4-dichlorobenzene. Prepared by Research Triangle Institute under contract 205-93-0606. U.S. Department of Health & Human Services, Public Health Service. PB-99-121972.

Anderson, D., and Hodge, M. 1976. Para-dichlorobenzene: Dominant Lethal Study in the Mouse: Rept. No. CTL/P/296. Unpublished study prepared by Imperial Chemical Industries, LTD. Submitted to the U.S. Environmental Protection Agency under FIFRA. MRID40521011.

California. 1991. California Code of Regulations, Title 22, Section 12000.

Chemical Market Reporter. 1999. Chemical profile. p-dichlorobenzene. Schnell Publishing. June 7, p. 37.

Erickson, M. D., Harris, S. H. III, Pellizzari, E. D., Tomer, K. B., Waddell, R. D., and Whitaker, D. A. 1980. Acquisition and chemical analysis of mother's milk for selected toxic substances. EPA 560/13–80–029, PB81–231029, prepared for the Office of Pesticides and Toxic Substances, U.S. EPA, Washington, DC, under Contract 68–01–3849.

European Union. 2000. Commission Directive 2000/32/EC. Off. J. Eur. Commun. 26th ATP, L 136/1. Amendment to Council Directive of 27 June 1967 on the approximation of laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances.

European Union. 2004. 1,4–Dichlorobenzene. European Union Risk Assessment Report. European Chemicals Bureau: Existing Substances. Institute for Health and Consumer Protection, Vol. 48, EUR 21313 EN. European Communities.

Firmenich, Inc. 1982. Test for mutagenic activity in Salmonella typhimurium TA 1535, TA 1537, TA 1538, TA 98, and TA 100. Submitted to U.S. EPA. NTIS/OTS0206483, TSCA Sect. 8D.

Globol Werke GmbH. 1986. Messungen der p-dichlorbenzol-Konzentration in Raumen bei Verwendung von: p-DCB Mottentabletten, p-DCB Urinal-Beckensteinen; pDCB Luftverbesserertabletten. Untersuchungsbericht Nr 1507.

Heitland, H.-J., Marsen, H., and Schlussler, H.-J. 1986. Cleansing agents. In Ullmann's encyclopedia of industrial chemistry, ed. W. Gerhartz, Vol. A7, p. 145. New York: VCH. Helmig, D., Klinger, L. F., Guenther, A., Vierling, L., Geron, C., and Zimmerman, P. 1999. Biogenic volatile organic compound emissions (BVOCs) 1. Identifications from three continental sites in the U.S. Chemosphere 38:2163–2187.

Hill Top Research, Inc. 1991. Letter submitting two enclosed studies on dimethyl-3-cyclohexene-1-carboxaldehyde with attachments (sanitized). U.S. EPA/OPTS Public Files, NTIS/EPA OTS0535068, Section 8D. Produced 11/25/91 by Hill Top Research, Inc, original research conducted by Leberco Laboratories in 1965.

Hodge, M., Palmer, S., Bennett, I., et al. 1977. Para-dichlorobenzene: Teratogenicity Study in Rats: Rept. No. CTL/P/340. Unpublished study prepared by Imperial Chemical Industries, Ltd. Submitted to the U.S. Environmental Protection Agency under FIFRA. MRID40521002.

Imperial Chemical Industries Limited. 1982. Para-dichlorobenzene Long Term Inhalation Study in the Rat. Submitted to the U.S. Environmental Protection Agency under TSCA Section 4. U.S. EPA/OPTS Public Files, Doc#: 40-8220833, Fiche #OTS0511381. NTIS document number OTS0511381.

InfoScientific. 1998. THERdbASE (Total Human Exposure Relational database and Advanced Simulation Environment) Model 401. Version 1.0. InfoScientific.com

Naylor, M. W., and Stout, L. D. 1996. One year study of p-dichlorobenzene administered orally via capsule to beagle dogs. Environmental Health Laboratory, Monsanto Company, St. Louis, MO. Study ML-94–210, March 25, 1996. MRID 43988802. Unpublished.

New York State. 2004. Consolidated Laws of New York, Chapter 270, Title 1, Article 9 (School Buildings and Sites), Section 409-g, Purchase and use of paradichlorobenzene deodorizers.

RIFM (Research Institute for Fragrance Materials). 2003a. Cyclacet. Obtained from S.C. Johnson, personal communication.

RIFM (Research Institute for Fragrance Materials). 2003b. Dihydromyrcenol. Obtained from S.C. Johnson, personal communication.

RIFM (Research Institute for Fragrance Materials). 2003c. Hexanal. Obtained from S.C. Johnson, personal communication.

RIFM (Research Institute for Fragrance Materials). 2003d. Eucalyptol. Obtained from S.C. Johnson, personal communication.

RIFM (Research Institute for Fragrance Materials). 2003e. Benzyl acetate. Obtained from S.C. Johnson, personal communication.

Vergnes, J. S., and Morabit, E. R. 1995. Aldeyde AA (crude): Mutagenic potential in the Salmonella/microsome (Ames) assay. Performing laboratory: Bushy Run Research Center, Export, PA, for Union Carbide Corporation. NTIS/OTS0557677, TSCA Section 8D.