Phosphate flame retardants (PFRs) are ubiquitous chemicals in the indoor environment. Diphenyl phosphate (DPHP) is a major metabolite and a common biomarker of aryl-PFRs. Since it is used as a chemical additive and it is a common impurity of aryl-PFRs as well as a degradation product, its presence in indoor dust as an additional source of exposure should not be easily ruled out. In this study, DPHP (and TPHP) are measured in indoor dust in samples collected in Spain and in the Netherlands (n = 80). Additionally, the presence of other emerging aryl-PFRs was monitored by target screening. TPHP and DPHP were present in all samples in the ranges 169–142,459 ng/g and 106–79,661 ng/g, respectively. DPHP concentrations were strongly correlated to the TPHP levels (r = 0.90, p < 0.01), suggesting that DPHP could be present as degradation product of TPHP or other aryl-PFRs. Estimated exposures for adults and toddlers in Spain to TPHP and DPHP via dust ingestion (country for which the number of samples was higher) were much lower than the estimated reference dose (US EPA) for TPHP. However, other routes of exposure may contribute to the overall internal exposure (diet, dermal contact with dust/consumer products and inhalation of indoor air). The estimated urinary DPHP levels for adults and toddlers in Spain (0.002–0.032 ng/mL) as a result of dust ingestion were low in comparison with the reported levels, indicating a low contribution of this source of contamination to the overall DPHP exposure. Other aryl-PFRs, namely cresyl diphenyl phosphate (CDP), resorcinol bis(diphenyl phosphate) (RDP), 2-ethylhexyl diphenyl phosphate (EDPHP), isodecyl diphenyl phosphate (IDP) and bisphenol A bis(diphenyl phosphate) (BDP), were all detected in indoor dust, however, with lower frequency.

磷酸盐阻燃剂（PFR）是室内环境中普遍存在的化学物质。磷酸二苯酯（DPHP）是主要的代谢产物，也是芳基PFR的常见生物标志物。由于它被用作化学添加剂，并且是芳基-PFR的常见杂质以及降解产物，因此，不应轻易排除其在室内粉尘中作为额外暴露源的存在。在这项研究中，DPHP（和TPHP）在西班牙和荷兰收集的样品中的室内灰尘中进行了测量（n = 80）。另外，通过靶标筛选监测其他新兴的芳基-PFR的存在。在所有样品中，TPHP和DPHP的含量分别为169-142,459 ng / g和106-79,661 ng / g。DPHP浓度与TPHP水平密切相关（r = 0.90，p <0.01），表明DPHP可能作为TPHP或其他芳基PFR的降解产物存在。西班牙成年人和幼儿通过粉尘摄入（样本数量较高的国家）暴露于TPHP和DPHP的估计暴露量远低于TPHP的估计参考剂量（美国EPA）。但是，其他暴露途径可能会导致整体内部暴露（饮食，皮肤接触粉尘/消费品以及吸入室内空气）。西班牙成人和幼儿的估计尿DPHP水平（0.002-0。灰尘摄入的结果是032 ng / mL），低于报告的水平，表明该污染源对DPHP的总体暴露影响很小。其他芳基-PFR，即磷酸甲酚二苯酯（CDP），间苯二酚双（磷酸二苯酯）（RDP），2-乙基己基磷酸二苯酯（EDPHP），磷酸异癸基二苯酯（IDP）和双酚A双磷酸二苯酯（BDP），都是在室内灰尘中检测到的，但是频率较低。