Cosmetics and personal care products are part of our daily routine. Their composition includes several chemicals such as preservatives, colorants, fixatives, and UV filters, which should be safe as they undergo a regulated risk assessment for hazard identification and exposure.
Some of these chemicals are potential Endocrine Disruptors or Endocrine-Disrupting Chemicals (EDCs). Endocrine disruptors are chemical substances that alter the functioning of the endocrine system and negatively affect the health of humans and animals. EDCs mimic the action of the body’s natural hormones, disrupting biological processes and even leading to reproductive-associated toxicity, neurodevelopmental disorders, and corticoid and thyroid dysfunction.
EDCs have been a point of anxiety in recent years as more and more literature is coming to light reflecting their harmful health effects. In the case of cosmetic products, which involve daily use, risk assessment is essential.
Which endocrine disruptors may be present in cosmetic products?
EDCs are present in the environment, and humans are inevitably exposed to them through water and food intake, via inhalation, and through the skin. In the case of personal care products, the primary exposure route is the skin. EDCs present in cosmetic products can penetrate the skin barrier and enter the systemic circulation. Other routes are contemplated, such as inhalation in fragrances and hair sprays, and accidental ingestion of lipsticks.
Among the potential EDCs present in cosmetics, parabens, and phthalate esters are the primary sources of focus and concern.
Parabens are a class of synthetic esters commonly used as preservatives due to their antimicrobial properties. They have been a topic of debate due to their potential to mimic estrogen. Research on the safety of parabens is ongoing, and some studies have suggested a potential link between parabens and hormone disruption, exhibiting estrogenic and antiandrogenic activities, resulting in reproductive dysfunction.
Phthalate esters are used in cosmetic products to enhance the fragrance, increase flexibility, or improve the performance of specific formulations, and the body can absorb phthalates through different routes. These esters bind to target receptors and disrupt hormonal homeostasis. They have been related to sex-specific reproductive problems and adverse effects in newborns due to prenatal exposure.
Other potential hormone disruptors include antiseptics, UV filters, and musk fragrances.
Is EDC use in cosmetics regulated?
Regulation (EC) No 1223/2009 concerning cosmetic products establishes a regulatory framework safeguarding human health in the European Union (EU). In the United States, the safety of cosmetic products is ensured by the 1938 Federal Food, Drug, and Cosmetic Act, recently updated through the Modernization of Cosmetics Regulation Act of 2022.
Both regulations incorporate restrictions and bans on certain substances in cosmetics to mitigate potential health risks. In the EU, these restrictions are guided by risk assessments conducted by the Scientific Committee on Consumer Safety (SCCS). The SCCS evaluates concerns regarding the endocrine-disrupting properties of substances in cosmetics and other problematic compounds. Their assessment determines whether endocrine/hormonal activities are associated with critical endpoints, thus gauging the safety of these substances for consumers.
On November 7th, 2018, the Commission approved the revision of Regulation (EC) No 1223/2009 on cosmetic products containing endocrine-disrupting substances. Following consultation with EU countries, industry stakeholders, consumer organizations, and the SCCS, the Commission compiled 28 substances, including certain phthalates and parabens.
In contrast, the Food and Drug Administration (FDA) lacks explicit regulations addressing endocrine disruptors in cosmetic products. Instead, the FDA relies on a voluntary cosmetic registration program and encourages the cosmetic industry to adhere to good manufacturing practices (GMP) to uphold product safety.
Zebrafish as a New Alternative Model (NAM) for the study of Endocrine Disruptors
While traditional toxicology mainly uses mammal models such as rats and mice, new gene editing, genomics, and neuroimaging techniques in various species offer exciting possibilities to advance research on endocrine-disrupting chemicals. NAMs lead towards a more humane state of animal testing, avoiding ethical concerns.
Zebrafish is a perfect NAM that is highly reliable, easy to rear, and bread. The external fertilization, fast development, and transparency make it a helpful and cost-effective model in high-scale EDC risk assessment for the cosmetic industry.
Biobide has developed several endocrine disruption assays, precisely thyroid inhibition and estrogen inhibition High-Content Screening assays using Zebrafish.
Our endocrine disruption assays are set up to evaluate the maximum tolerated concentration first, setting a reference point for subsequent assessments. Zebrafish transparency and genetic modification to generate transgenic embryos expressing fluorescent thyroglobulin allow us to analyze protein levels by image analysis.
We have developed an extended EDCs characterization that includes the expression analysis of genes related to EDCs, such as thyroid disruption or estrogen pathways, including the gene expression analysis. We can also analyze alterations in T4/T3 hormones detected for the EDCs through LC-Ms-Ms techniques in zebrafish embryos treated with them.
Research is crucial to examine the impact of EDCs on human health. Biobide’s efforts to offer reliable, High-Content Screening assays bring us one step closer to the mission of developing safe cosmetic products for consumers and preserving the population’s health.
Sources
European Commission. Endocrine disruptors. [Internet]. [cited 2024 Jan 17]. Available from:https://single-market-economy.ec.europa.eu/sectors/cosmetics/cosmetic-products-specific-topics/endocrine-disruptors_en
Center for Food Safety and Applied Nutrition. Modernization of Cosmetics Regulation Act of 2022 [Internet]. Food and Drug Administration; [cited 2024 Jan 17]. Available from:https://www.fda.gov/cosmetics/cosmetics-laws-regulations/modernization-cosmetics-regulation-act-2022-mocra
Kalofiri P, Biskanaki F, Kefala V, Tertipi N, Sfyri E, Rallis E. Endocrine Disruptors in Cosmetic Products and the Regulatory Framework: Public Health Implications. Cosmetics. Nov 2023;10(6):160.
Martín-Pozo L, Gómez-Regalado MDC, Moscoso-Ruiz I, Zafra-Gómez A. Analytical methods for the determination of endocrine disrupting chemicals in cosmetics and personal care products: A review. Talanta. Nov 2021;234:122642.
Patisaul HB, Fenton SE, Aylor D. Animal models of endocrine disruption. Best Practice & Research Clinical Endocrinology & Metabolism. Jun 2018;32(3):283-97.
