Endocrine Disruptors: An Overview on Propylparaben and Salicylic Acid

Cosmetic products are an integral part of our daily routines, and consumers are increasingly concerned about the ingredients they apply to their bodies and the potential consequences of their use. To protect human health, the Scientific Committee on Consumer Safety (SCCS) conducts risk assessments to address concerns related to substances that may pose potential health risks to consumers. The outcomes of these risk assessments can lead to the implementation of new restrictions or bans on certain substances within cosmetic products in the European Union.

Endocrine disruptors have been a significant concern in the European Union for some time, prompting efforts to understand and regulate substances with these properties. But what exactly are endocrine disruptors? They are chemical substances that alter the functioning of the endocrine system, negatively impacting the health of both humans and animals. These substances have the ability to mimic, block, or alter the normal functioning of hormones.

The endocrine system plays a pivotal role in regulating various bodily functions, including growth, metabolism, and reproductive health. Exposure to endocrine disruptors can potentially result in health issues such as hormonal imbalances, reproductive problems, cancer, developmental disorders, and thyroid dysfunction. Substances with endocrine-disrupting properties can be either synthetic or of animal origin.

Although the Regulations do not provide a specific protocol for addressing endocrine disruptors, in 2019, the European Commission initiated a Fitness Check to evaluate whether the relevant EU legislation regarding endocrine disruptors effectively achieved its overarching goal of safeguarding human health and the environment.

This assessment revealed that the procedures outlined in the Regulation, such as the risk assessments performed by the SCCS, as previously described, are appropriate when identifying a substance as a potential endocrine disruptor. In these risk assessments, it is crucial to establish a causal relationship between the substance’s induced endocrine activity and the observed adverse effects.

In 2019, the European Commission compiled a priority list of 28 substances with potential endocrine-disrupting properties that are used in cosmetics. This list was divided into two groups: Group A, which represented substances of high priority, and Group B, comprising substances of low priority. The SCCS was tasked with conducting risk assessments for each of these substances. Based on these assessments, appropriate measures, such as the imposition of restrictions or bans by including the substances in Annexes II or III of Regulation (EC) No. 1223/2009, were implemented.

Two of the substances present on this priority list were propylparaben and salicylic acid.

Propylparaben

Propylparaben is a synthetic compound belonging to the well-known group of preservatives called parabens, which are commonly used in cosmetic and personal care products. Currently, propylparaben is listed in Annex V, which is the list of approved preservatives for cosmetics, as specified in Regulation (EC) No. 1223/2009. The safety of parabens, including propylparaben, has been subject to multiple assessments by the SCCS. The most recent opinion, issued in March 2021 after propylparaben was placed on the priority list, concluded that “propylparaben is safe when used as a preservative in cosmetic products at a maximum concentration of 0.14%.“

The report also acknowledged the presence of data indicating potential endocrine effects associated with propylparaben. However, at that time, the available evidence was not sufficient to classify it as an endocrine-disrupting substance or to establish a toxicological point of departure based on endocrine-disrupting properties for use in human health risk assessment.

Nevertheless, it’s important to note that propylparaben does possess endocrine-disrupting properties that can mimic the female hormone oestrogen when absorbed by the body. As a result, it is considered a potential endocrine disruptor.

Salicylic Acid 

Salicylic acid is classified as a beta-hydroxy acid and can be found naturally in various plants. It is a commonly used ingredient in cosmetic products, primarily due to its effectiveness in acne formulations and its exfoliating properties. Additionally, salicylic acid is utilised as a preservative to safeguard cosmetic formulas against microbial growth.

Similar to propylparaben, salicylic acid was included in the consolidated list of 28 substances with potential endocrine-disrupting properties. However, it was placed in Group B, which denotes low priority. This categorization was based on the fact that salicylic acid had not undergone evaluation under REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals) or yielded any concerns related to human health.

As per the SCCS opinion on Salicylic acid, this substance continues to be listed in Annex III, with maximum concentration allowances of 3% for rinse-off hair products and 2% for other products, taking into account the existing restrictions in place. Additionally, for body lotion, eye shadow, mascara, eyeliner, lipstick, and roll-on deodorant, the maximum concentration allowed remains at 0.5%.

Following the request for additional information on these substances, no additional restrictions or bans have been imposed on either propylparaben or salicylic acid. The debate surrounding these two substances as potential endocrine disruptors primarily hinges on the absence of conclusive evidence. While studies have raised concerns about both substances, it is crucial to note that the assessment of their potential risks is significantly influenced by their concentration and frequency of use.

Concerning propylparaben, research on its estrogenic effects has yielded mixed results. Some studies suggest that it may influence hormonal activity at higher concentrations, while others indicate that typical exposure levels in cosmetics and personal care products may not pose significant risks.

On the other hand, salicylic acid is not typically regarded as an endocrine disruptor. However, concerns arise from the possibility of skin absorption and its potential impact on hormone levels when used in high doses.

The debate surrounding propylparaben and salicylic acid as potential endocrine disruptors continues without a definitive consensus within the scientific community. While concerns persist, the associated risks with these ingredients are largely contingent on the concentration and frequency of exposure. It remains imperative to provide consumers with all the necessary information regarding formulations so that they can make informed choices about the products they use.

As EU regulations become increasingly stringent and more information becomes available, it is anticipated that more substances will undergo review, leading to further restrictions and the potential banning of commonly used cosmetic ingredients. The overarching objective of health authorities across the EU is to offer consumers the safest formulations to safeguard both human health and the environment.