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.
The level of the active is the other obvious candidate. I remember when I worked for a company that made high strength deodorants with really high aluminium content intended for use by people with extreme levels of sweating. Periodically someone working there would try the product themselves. It looked just like any other deodorant. The effect was very much that reported with these Mitchum products.
It is easy to see how a mistake along these lines could happen. Aluminium salts are purchased as concentrates. If a manufacturing process was changed and a different strength of concentrate switched to, well there’s quite a few ways that might go wrong. You could use the old strength instead of the new one. Someone could have got the calculation wrong when the formulation was changed.
So if I was called in to investigate – which is the sort of thing I do – I’d be looking at the records of the aluminum salt suppliers, the records in the warehouse, the calculations made in the lab and the records of the manufacture of the affected batches. Cosmetics are made following a standard that requires all these records to be kept. It’s when something goes wrong, as appears to have happened here, that the effort of keeping records pays off. In the first instance the batch numbers of the affected products allows them to be recalled quickly and efficiently. Then an investigation needs to be carried out into how the mistake was made. Conclusions can then be drawn about how to make sure it doesn’t happen again. I imagine that all this has already been done.
The big losers of course are the people who ended up using the product. I’d treat the affected area with a product that combines anti-inflammatory and anti-bacterial effects. There are several creams available in the UK that combine both anti-inflammatory and anti-bacterial properties. Mainstream products that work well for these purposes are ones that contain silver salts, shea butter and if it is really painful hydrocortisone. Both these have strong scientific backing and should work effectively for most people. For those who prefer something natural rather than something that works well, aloe vera and oatmeal are both good options.
(P.S., the extensive media coverage of this story in the UK has described the product as a deodorant, and that is how Mitchum themselves describe it. But strictly speaking the incorporation of an aluminium salt makes it an antiperspirant. I’ve used the word deodorant in this article to avoid confusion.)