While Diethylamino Hydroxybenzoyl Hexyl Benzoate (DHHB), also known as Uvinul A Plus, is a common sunscreen ingredient that absorbs UVA rays, it has potential downsides. It may cause allergic reactions and some studies suggest it might disrupt hormones. DHHB can also increase sun sensitivity and irritate the skin. Like other chemical sunscreens, it can harm coral reefs. The FDA hasn’t approved DHHB for sunscreens, and stricter regulations exist in some areas due to environmental concerns. In the EU, DHHB has been limited to a maximum concentration of 10% in cosmetic products.

Ethanolamines, like Monoethanolamine (MEA), Diethanolamine (DEA), and Triethanolamine (TEA), are common cosmetic ingredients that act as emulsifiers, surfactants, and pH adjusters. While they offer functionality, ethanolamines can irritate the skin and eyes, especially at higher concentrations or with frequent use. In some individuals, they may even trigger allergic reactions. A more concerning issue is their potential to form nitrosamines, known carcinogens, when interacting with nitrosating agents sometimes present in cosmetics. Due to this risk, several regulatory bodies have taken action. Health Canada has banned DEA completely, while the EU and Japan restrict its use and classify it as a substance of very high concern. While the evidence for endocrine disruption is less conclusive, these regulations highlight the potential health risks associated with ethanolamines.

While commonly used as preservatives in skincare and cosmetics, formaldehyde and formaldehyde-releasing ingredients raise safety concerns. Classified as a human carcinogen by the International Agency for Research on Cancer (IARC), formaldehyde can also irritate skin, trigger allergies, and cause respiratory issues. Due to these risks, formaldehyde itself is banned in cosmetics in the EU, Australia, Brazil, and South Korea. Similar concerns surround formaldehyde-releasing ingredients like quaternium-15, DMDM Hydantoin, imidazolidinyl urea, diazolidinyl urea, sodium hydroxymethylglycinate and 1-bromo-2-nitropropane-1,3-diol (bronopol). While not directly formaldehyde, these ingredients break down to release it over time. To safeguard consumers, most countries heavily restrict the use of these ingredients in cosmetics and closely monitor their presence.

While commonly used as preservatives in cosmetics, Methylisothiazolinone (MI) and Methylchloroisothiazolinone (MCI) raise concerns due to their potential to trigger allergies and irritation. They are known skin sensitisers, meaning they can cause allergic contact dermatitis, leading to redness, itching, swelling, and rashes. Severe reactions can include blistering. Some evidence suggests MI may even have neurotoxic effects. These risks are especially concerning for people with sensitive skin, as MI and MCI can irritate the skin and eyes even without causing allergies. To safeguard consumers, the EU, Australia, Canada, and Japan have banned MI in leave-on products and strictly limited its use in wash-off products. MCI use in cosmetics is restricted and closely monitored.

While oxybenzone (benzophenone) shields skin from UV rays in sunscreens and cosmetics, recent research highlights potential health and environmental risks. Classified as an endocrine disruptor, it mimics hormones like oestrogen, raising concerns about hormonal imbalances and reproductive health. Oxybenzone can also trigger skin allergies and is flagged as a possible carcinogen, warranting further investigation. Most concerning is its impact on marine life. Oxybenzone is highly toxic to coral reefs, causing bleaching even at low levels. To protect our oceans, Hawaii, Key West, Palau, and the US Virgin Islands have banned its use. The EU strictly limits oxybenzone in cosmetics and closely monitors its safety.

Butylated Hydroxyanisole (BHA) is a common preservative used in cosmetics, food, and pharmaceuticals to extend shelf life by preventing fat and oil spoilage, potential health risks are a growing concern. Classified as a possible human carcinogen by the International Agency for Research on Cancer (IARC), BHA is an endocrine disruptor and has also been linked to kidney and liver damage in animal studies. It can also cause skin irritation and allergies in some people. Due to these concerns, the EU, Canada, Australia, and Japan have implemented strict guidelines and limitations on BHA concentration in cosmetics.

Phenoxyethanol is a common preservative in cosmetics that extends shelf life, but potential health risks exist. It can irritate skin and trigger allergies, particularly for sensitive individuals. Some studies suggest possible neurotoxic effects in infants, leading the FDA to advise against its use in infant products. In addition, trace amounts of ethylene oxide (known carcinogen) and 1,4-dioxane (possible carcinogen) might be present due to the manufacturing process. To ensure safety, the EU, US, Canada, and Australia limit phenoxyethanol concentration to 1% or less in cosmetics.

Commonly used for flexibility, longevity and fragrance in skincare and cosmetics, raises several health concerns. These chemicals are linked to hormonal disruption, potentially impacting fertility, sexual development, and hormone balance in both men and women. Studies suggest lower sperm count in men and endometriosis in women. Prenatal exposure might also affect foetal development, and some phthalates are flagged as possible carcinogens. The EU has banned several phthalates in cosmetics such as dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP), and benzyl butyl phthalate (BBP). Countries like Canada, Australia, and Japan have restrictions and safety monitoring in place.