Retinoids are a broad class of compounds related by their vitamin A or ‘vitamin A-like’ activity. They occur naturally and are also synthetically produced. They are frequently used in various applications, including cosmetics.

Vitamin A traditionally referred solely to retinol, which is a normal component of the human diet. Through research, it was later discovered that the biological activity is actually attributed to its carboxylic acid, retinoic acid. The body controls levels of retinoic acid within a tight range, as it influences cell growth and development. Levels are maintained through a sequence of metabolic steps from the storage form (ester derivatives) to retinol, and from retinol to retinaldehyde (or more commonly ‘retinal’), and eventually from retinal to retinoic acid.

When levels of retinoic acid are altered, it can impact cellular growth. This may be desirable in some cases (e.g. when applied on the skin, it can help with conditions such as acne or photo-damage), whilst in other cases it may be negative (e.g. if it interferes with development in the context of foetal growth).

Over the past two years, both the European Union and Australia have changed their regulations related to retinoid use in cosmetic products. Although changes in both jurisdictions relate to vitamin A derivatives, they arose from different regulatory reviews and apply to different substances.

European Union (EU): Concentration limits and mandatory labelling for Vitamin A

The EU’s Scientific Committee on Consumer Safety (SCCS) revisited its opinion on retinol, retinyl acetate and retinyl palmitate in its revised opinion SCCS/1639/21. The SCCS concluded that these ingredients are safe for use in cosmetics at concentrations of up to 0.05% retinol equivalents (RE) in body lotions and 0.3% RE in other leave-on and rinse-off products.

The safety concern that motivated regulatory action was due to aggregate exposure predictions. SCCS’s probabilistic modelling found that the most exposed 5% of the population may already be close to or exceeding the Tolerable Upper Intake Level for Vitamin A from food and supplements alone, before cosmetics are factored in.

This aggregate exposure finding influenced Commission Regulation (EU) 2024/996 (3 April 2024), which amended Annex III of the Cosmetics Regulation (EC) No 1223/2009 to:

• Cap retinol, retinyl acetate and retinyl palmitate at 0.05% RE in body lotion and 0.3% RE in other leave-on/rinse-off products.

• Require the label statement “Contains Vitamin A. Consider your daily intake before use” on affected products.

Compliance timeline: products containing these substances that do not comply with the new requirements could no longer be placed on the Union market from 1 November 2025. Products already placed on the Union market before that date may continue to be made available until 1 May 2027.

Australia: AICIS reclassifies retinal (retinaldehyde)

The Australian Industrial Chemicals Introduction Scheme (AICIS) completed a targeted human health hazard assessment of retinal (retinaldehyde). AICIS evaluated retinal specifically for developmental

toxicity, because it was not on the Australian Inventory and had previously been introduced under the reported and exempted categories.

AICIS concluded that retinal has developmental toxicity and is classified as a developmental toxin. As a result, from 27 June 2026, retinal intended for consumer use, including, for example, cosmetic serums, creams and lotions, no longer qualifies for the exempted or reported introduction pathways. Importers and manufacturers must now obtain an AICIS assessment certificate before introducing retinal into Australia.

Importantly, this change is currently scoped to retinal specifically. It does not apply to retinol and retinol esters, which remain listed on the existing Australian Inventory of Industrial Chemicals.

What this means for formulators and brands:

Australia:

· Businesses importing or manufacturing retinal for consumer cosmetic use must obtain an AICIS Assessment Certificate before introduction.

· There are currently no equivalent regulatory changes affecting retinol or retinyl esters in Australia.

European Union:

· Verify that products containing retinol, retinyl acetate or retinyl palmitate comply with the new concentration limits.

· Ensure affected products include the mandatory vitamin A warning statement.

· Confirm that products remaining on the market after 1 May 2027 comply with the amended requirements.

Sources:

• SCCS Revision of the Scientific Opinion (SCCS/1576/16) on Vitamin A;

• Commission Regulation (EU) 2024/996; • Australian Industrial Chemicals Introduction Scheme, “Retinal introductions for consumer use now need assessment by AICIS.”