Irungu Beatrice N, Llanos Adana A M, Nyangi Mary, Olisa Teresa, Matu Esther, Rockson Amber, Schaefer Alexis, Ashrafi Adiba, Terry Mary Beth, McDonald Jasmine A, Nudelman Janet, Gillan Laura Dobbs, Chowdhary Pujeeta, Wachira Sabina, Kimani Cecilia
Center for Traditional Medicine and Drug Research, Kenya Medical Research Institute, Nairobi, Kenya.
Department of Epidemiology, Mailman School of Public Health, Columbia University Irving Medical Center, New York, NY, United States.
Front Public Health. 2025 Apr 16;13:1532113. doi: 10.3389/fpubh.2025.1532113. eCollection 2025.
There is an emerging interest in the investigation of hair relaxers as important sources of exposure to chemicals of concern (CoCs) and their associated adverse health effects. We focused on documentation of CoCs by examining labels of selected relaxers currently available on the market in Nakuru and Embu Counties, Kenya and measured the pH profiles to ensure compliance with Kenya Bureau of Standards.
We enrolled 746 women aged 15-50 years in a cross-sectional study, which ascertained participants' sociodemographic characteristics, personal care products use in the last 7-14 days and ever use of hair dyes and chemical relaxers including the brand names of products used. Based on participants' questionnaire responses and product availability at beauty shops and supermarkets, we purchased 22 different relaxer products. The label of each product was reviewed and we recorded relaxer strength, manufacturer and location, listed ingredients, and other claims. To identify CoCs, we cross-checked the list of ingredients against the Campaign for Safe Cosmetics' (CSC) Red List and European Union's prohibited and restricted substances (Annex II and III respectively), Regulation 1223/2009 on cosmetics. The pH profiles of each product were determined using a benchtop pH meter.
Twenty-seven CoCs were documented upon examination with each relaxer listing more than one CoC. Thirteen out of 27 (48.2%) were fragrance chemicals with d-limonene/limonene and linalool, each being listed as an ingredient in 9 products. Fourteen (63.6%) relaxers had undisclosed ingredients listed as 'fragrance' and/or 'parfum'. Six of the identified CoCs are classified as Tier 1 (Do not use for everyone) per CSC Red List while 14.8% (4) are prohibited and 55.6% (15) are restricted substances per EU regulations. The pH values of the relaxers were within Kenya Bureau of Standards required range of 11-13.
These findings create awareness of CoCs listed on labels of selected hair relaxers. This justifies the need for consumer education on potentially harmful chemicals and their associated risks. Further, our findings justify the need for laboratory study to evaluate and quantify CoCs that are listed as well as those that are not listed on the label.
人们越来越关注直发剂，将其视为接触相关化学物质（CoC）的重要来源以及其相关的不良健康影响。我们通过检查肯尼亚纳库鲁县和恩布县市场上现有的部分直发剂标签来记录CoC，并测量pH值以确保符合肯尼亚标准局的规定。
我们招募了746名年龄在15至50岁之间的女性参与一项横断面研究，该研究确定了参与者的社会人口学特征、过去7至14天内使用的个人护理产品以及是否曾使用染发剂和化学直发剂，包括所使用产品的品牌名称。根据参与者的问卷回答以及美容店和超市中产品的可得性，我们购买了22种不同的直发剂产品。审查了每种产品的标签，并记录了直发剂强度、制造商和产地、列出的成分以及其他声明。为了识别CoC，我们将成分列表与安全化妆品运动（CSC）的红色清单以及欧盟的禁用和限制物质（分别为附件II和III）、关于化妆品的第1223/2009号法规进行了交叉核对。使用台式pH计测定每种产品的pH值。
检查发现有27种CoC，每种直发剂列出的CoC不止一种。27种中的13种（48.2%）是香料化学品，d - 柠檬烯/柠檬烯和芳樟醇，每种都在9种产品中被列为成分。14种（63.6%）直发剂有未公开的成分列为“香料”和/或“香水”。根据CSC红色清单，所识别的CoC中有6种被归类为1级（并非所有人都适用），而根据欧盟法规，14.8%（4种）被禁止，55.6%（15种）是限制物质。直发剂的pH值在肯尼亚标准局要求的11至13范围内。
这些发现提高了人们对所选直发剂标签上列出的CoC的认识。这证明有必要对消费者进行关于潜在有害化学物质及其相关风险的教育。此外，我们的发现证明有必要进行实验室研究，以评估和量化标签上列出以及未列出的CoC。
