Nomination Summary for Application of Tox21 techniques to consumer products designed for use by young children (N21702)
Nominated Substances: KIDSPRODUCTSTOX21
Nomination Date: 04/04/2017
Nominator: State of Connecticut Department of Public Health
Rationale: The State of Connecticut, along with other states, have been compiling lists of chemicals of high concern due to their presence in children's products or otherwise in the home or early learning environment. It is uncertain as to whether such lists reflect the composition of consumer products currently on the market. This is uncertain because of limited information on ingredients as well as because the marketplace rapidly changes in response to economic, health and environmental concerns. As one chemical becomes of high concern, alternatives which may also be toxic or which may be untested, may be used as replacements. Several important chemicals in the home environment have "emerged" in recent years, particularly in the flame retardant, phthalate and perfluorinated groupings. However, there may be other biologically active chemicals currently in products that have yet to emerge. A focus on young children is important because their extensive mouthing behavior can lead to greater exposure and there are products for this age group which may be a unique source of exposure. Young children may also have slower clearance and greater vulnerability to such exposures. To improve our detection of emerging contaminants in children's products we propose that NTP use Tox21 approaches to identify biological activities of potential concern in these products. The only example of bioassay information relating to young children's exposures that we are aware of is the detection of mutagens in house dust. At least some of that mutagenic activity appears to stem from azo dyes that may still be used in clothing and household furnishings (Peng et al. 2016). The recent advancement in high throughput assays to screen tested and untested chemicals has made Tox21 a key resource for toxicology screening. In addition, it is becoming of increasing importance in understanding the value of upstream indicators of toxicity from both a systems biology as well as public health/risk assessment context. Tox21 type high throughput screening has been used to assess the biological activities associated with wastewater treatment plant effluent, receiving river water, and finished drinking water (Escher et al. 2014). We expect that the application of high throughput screening to environmental samples will grow. The use of this technology to evaluate children's products presents an important public health-relevant opportunity in this direction. While our nomination is of a general nature we offer the following bioactivities and products to illustrate the type of screening we would like NTP to conduct. Suggested assays to screen for activities of potential concern: cytotoxicity, estrogenic activity, androgenic activity, gonadotropin activity, AhR activation, p53 modulation, PPAR activation, PXR/CAR activation, oxidative stress/signaling, and mutagenicity/genotoxicity Possible products to test: infant sleepwear, crib/carseat padding, sleep mats, diapers, teethers/pacifiers, plush toys, plastic bath toys, toy jewelry, plastic clothing items (e.g. vinyl shoes), baby bottles, house dust (House dust is obviously not a product but is derived from products and the built environment. House dust sampled from a child's bedroom can be compared to other indoor environments to help increase relevance to children.) The products listed would need some form of biologically relevant extraction such as simulated saliva for items likely to be mouthed or simulated sweat for products which are worn (e.g., diapers) and possibly also urine (e.g. diapers). The evaluation of a particular product area might possibly involve the following three stages: 1) Testing of a product class by compositing across multiple brands; 2) Discrete testing within a class to determine the range of activity within that class; 3) Bioassay-based fractionation and analytical chemistry analysis to identify the chemical(s) producing the bioactivity. CT DPH does not plan to conduct a risk assessment or other quantitative analysis of the results, but rather hopes to evaluate whether there are additional emerging contaminants in children's products that bear biological activities of potential toxicological concern. This might then provide the basis for prioritizing such contaminants for further toxicity testing, exposure assessment or alternative assessment in which replacement ingredients without the identified biological activities could be found. Please let me know if you would like to discuss any aspect of this nomination and please keep us informed as to your consideration of its merits. References Escher Bl, Allinson M, Altenburger R, et al. (2014) Benchmarking organic micropollutants in wastewater, recycled water and drinking water with in vitro bioassays. Environ Sci Technol. 48: 1940-1956. Peng H, Saunders DM, Sun J, Jones PD, Wong CK, Liu H,Giesy JP (2016) Mutagenic Azo Dyes, Rather Than Flame Retardants, Are the Predominant Brominated Compounds in House Dust. Environ Sci Technol. 50: 12669-12677.
NTP Principles: not specified