Ingredients

All about cosmetic and personal care ingredients. Information about their chemistry, their uses and their safety for consumers and the environment. If there’s some interesting background or history, that as well.

Mitchum Recalls Products That Irritate Users’ Armpits

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I’m intrigued by the story about Mitchum having to recall some batches of their deodorant due to intense irritation affecting users. They have announced that the problem is caused by a change to the manufacturing method. I am at a loss to guess what kind of change that might be. The active in most deodorants is aluminium in various salt forms. Mitchum seems to use two – Aluminum Zirconium Tetrachlorohydrex Gly or Aluminum Chlorohydrate. The pH is quite important in this, but although that might be part of the issue I’d be very surprised indeed if someone had got the pH of the batches in question wrong. It’s about the easiest thing to measure and adjust.

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Blackthorn Salt

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Blackthorn Salt is made using a traditional method.

Salt is one of those ingredients it is easy to overlook. It’s in almost everything we use in the beauty world, but it doesn’t exactly set the heart racing. You never hear anyone say, “Ooh, the salt in this really makes it for me!” Normally it sits there in the background, keeping things together, thickening up cleansers, or providing the basic mineral backbone in a formula. It’s all very useful, but frankly, a bit bland.

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TPO Ban – How Worried Should You Be?

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Beautiful nails achieved by UV hardening

The European Union ban on TPO (Trimethylbenzoyl Diphenylphosphine Oxide) in nail products is making headlines and getting plenty of attention, especially from papers like the Daily Mail, who never miss a chance for a good scare story. Is it time for fans of well manicure nails to panic?

What is TPO and why is it banned?

TPO is a photoinitiator used in gel nail polishes. It helps the product set hard and stay glossy for longer when it’s cured under UV light. In September 2025, the EU made it official: TPO is banned from all cosmetic products, citing animal studies that suggested large doses could harm fertility in rats. No human studies showed the same risk, and typical use in nail products sees TPO locked in the cured gel, not floating around to be absorbed.

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Prostaglandin analogues for eyelash growth – do they work; are they dangerous?

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Prostaglandins are used in eyelash serums to promote eyelash growth
Prostaglandins are used in eyelash serums to promote eyelash growth

Prostaglandins are one of the body’s messengers that regulate various activities that keep us functioning effectively. They pop up all over the place, but one that’s particularly interesting to a lot of people is that there are prostaglandins that control the rate of hair growth.

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Tallow in Skincare Part 4 – Why is Tallow Buzzy Right Now?

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It isn’t always obvious why a particular ingredient becomes suddenly popular. In the case of tallow it’s particularly difficult to work it out. It’s certainly a material that has got a lot going for it in terms of skin benefits. But it also has a lot of negatives in that it’s not very green and it’s not very good for vegetarians and vegans.

Tallow in Skincare Part 3 – Formulating with Tallow

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Tallow is a very traditional ingredient which older formulators will be used to using, although it has pretty much been absent from the skincare raw material palette for a couple of decades. It doesn’t present many challenges in the laboratory. In fact it’s quite a nice material to work with. It brings quite a lot of benefits. The biggest challenge it raises is sourcing it in a way that ensures safety.

Is BSE a Risk With Tallow Used In Skincare?

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Tallow, a purified fat from cattle and other large mammals, was once the main feedstock used to make soaps and many other cosmetic ingredients. This changed with the arrival of BSE, or mad cow disease, in the late 1980s and early 1990s. BSE is a brain disease that affected some cattle herds and caused a great deal of concern because it was linked with a similar disease in humans. This led to some dramatic changes in the way animal-derived ingredients are handled in all kinds of products, including cosmetics.

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The New EU Allergen List

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Woman looking at Cosmetic and personal care ingredients

What’s Changing and Why?

The EU has issued a new Cosmetic allergen list

Until recently, EU law required cosmetic products to list 24 specific fragrance allergens on their packaging if they were present above very low levels. These rules were designed to help people who are sensitive to certain ingredients avoid products that might cause them problems. However, as our understanding of allergies has improved, it’s become clear that more substances can cause reactions than were previously listed.

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