THE TRUTH BEHIND EXPIRY DATES

Can deodorant go bad? What about shampoo?

WE ALL KNOW THAT MILK, cheese and fish can rot, but what about shaving cream? It's not an issue most men spend a lot of time worrying about. Take my friend Ari. When I asked him if he'd ever used a grooming product beyond its expiry date, he said, “Honestly, tons of them and I can't recall a problem. But then again, I'm male. If my shaving cream turned into sand, I would assume it was supposed to be that way.”

I love Ari, but the truth is, some grooming products can spoil. Whether that happens and how long it takes depends on the product's formulation and use of preservatives. And whereas an expired bottle of hair gel may not cause a national panic the way a batch of salmonella-laden fish fingers might, an out-of-date product can be ineffective at best or, in extreme cases, cause allergic reactions, rashes or even infections.

Ultimately freshness depends on a product's formulation. “Chemically speaking, there are two main types of formulas,” says Gay Timmons, the founder of Oh, Oh Organic, a cosmetic-ingredients distribution company. “Anhydrous formulas contain oils, but no water. Emulsions are a mix of water and oil.” Anhydrous products that contain perishable plant oils, such as flaxseed or borage, will oxidise and smell, much like food. Anhydrous formulas containing essential oils such as lavender or bergamot, which contain antioxidants, are

HOW LONG CAN I USE . . .

Fluoride toothpaste

12 to 18 months.

Anti-ageing moisturiser 12 months in a jar; 18 months in a tube. Less water and air escapes from a tube. Sunblock After 12 months, SPF will no longer be reliable.

Body lotion Up to 18 months.

Shaving cream Up to 24 months depending on the not likely to spoil, but because these oils are volatile, their aromas may lose potency. In general, expired anhydrous products, such as shaving oil, deodorant and lip balm, may still work and won't cause harm, but they could become gross or ineffective.

Emulsions, however, contain water, which can evaporate and dry out the product (hair gel) or grow bacteria or mould (moisturiser, lotion, shaving cream). The latter can lead to itching or a rash. In rare instances, you could develop a bacterial infection, especially if the tainted product gets into an open wound, your mouth or eyes. “Something would have to go pretty damn bad for that to happen,” Timmons says. What's more, by that time, the product would likely smell so disgusting you'd be unlikely to use it, even if you don't pay attention to that kind of thing.

“Most products are safe for six months to two years after they've been opened,” says Tom Wilscam, CEO of Hommage, a men's grooming company. Many companies use an open-bottle-cap icon with a number and an “M” (for “months”), 12M, say, to indicate how long the product will remain stable after it's been opened. These icons can usually be found under the ingredients list on the back of the bottle. Use them as your guide.