Mixtures of methylisothiazolinone and methylchloroisothiazolinone are used as biocides in cosmetics, cleaning agents, and water-based paint. A biomonitoring method to evaluate exposure to these compounds was developed using N-methylmalonamic acid (NMMA), the main metabolite of both, methylisothiazolinone and methylchloroisothiazolinone, as the exposure biomarker. First-morning void urine samples (N = 2078) of 3- to 17-year-old children and adolescents living in Germany were analysed for concentrations of NMMA in the population representative German Environmental Survey for Children and Adolescents GerES V (2014–2017). NMMA was quantified in almost all samples, with a geometric mean concentration of 6.245 μg/L (5.303 μg/g_crea) and a 95th percentile of 15.0 μg/L (12.6 μg/g_crea). Urinary concentrations could not be related to self-reported application of specific cleaning agents or personal care products, leaving potential, specific sources of exposure unrevealed as most products relevant for isothiazolinone exposure are used ubiquitously.

For the first time, reference values can be derived for urinary NMMA for children and adolescents in Germany, facilitating a more substantiated exposure assessment.

甲基异噻唑啉酮和甲基氯异噻唑啉酮的混合物在化妆品，清洁剂和水性涂料中用作杀菌剂。使用甲基异噻唑啉酮和甲基氯异噻唑啉酮的主要代谢产物N-甲基丙二酸（NMMA）作为暴露生物标志物，开发了一种评估这些化合物暴露的生物监测方法。对德国3至17岁儿童和青少年的第一时间清晨尿样（N = 2078）进行了人口代表性德国儿童和青少年环境调查GerES V（2014-2017）中的NMMA浓度分析。 。在几乎所有样品中对NMMA进​​行了定量，其几何平均浓度为6.245μg/ L（5.303μg/ g _crea）和95％的百分数为15.0μg/ L（12.6μg/ g ）_crea）。尿液浓度与自我报告的特定清洁剂或个人护理产品的使用无关，因为大多数与异噻唑啉酮有关的产品都被广泛使用，因此未透露潜在的特定暴露源。

首次可以得出德国儿童和青少年尿液NMMA的参考值，从而有助于进行更充分的暴露评估。