Boolean’s sizzling science question: I know some cosmetics, especially aerosols, come with recommended storage temperatures. (I suppose there’s a possibility that high heat may melt the product, denature certain molecules, or drive undesirable reactions. I don’t know whether some bulk shipment containers for cosmetics are temperature controlled but if you order something online, the product is bound to spend at least one day in the back of a hot UPS truck. Since I live in Texas and the temperature inside a closed vehicle can reach up to 200 degrees Fahrenheit, I was wondering if most cosmetic formulas were thermally stable enough to spend a few days in transit without alteration. Also since most aerosols warn consumers not to store at temperatures above 120 degrees Fahrenheit, I was wondering if there had been any incidents of these things exploding in the back of a UPS truck?

The Right Brain responds:
We’ve discussed the subject of stability testing of cosmetics in a previous post and yes heat can certainly have a detrimental effect on product quality. I don’t know about you, but I’d be very upset if my $300 jar of Frederic Fekkai Overnight Hair Repair showed up at my door as molten goo. But there’s not TOO much cause for concern because all reputable cosmetic companies test their products at elevated temperatures.

Cosmetic stability testing

High temperature testing is done for two reasons. The first reason is to predict the long term stability of the product at normal temperatures. Since the rate of most chemical reactions approximately double for every 10 degree Celsius increase in temperature you can tell if a product will be stable at room temperature for several years by testing it at elevated temperatures for several months.

The second reason for high temperature testing is to screen for exactly the kind of problem you mentioned: to find out if your Ecco Bella Lipstick will turn into “Yuck-a Bella” when it’s shipped to Texas (or to Dubai, or just about any place experiencing global warming!) While there’s no single standard worldwide temperature that is used, in general if a product is stable up to 50 or 54 degrees Celsius for up to 8 weeks, it should be absolutely fine under normal shipping conditions. If absolutely necessary heat (or cold) sensitive products can be shipped in temperature controlled vehicles but this can increase both cost and shipping time.

Exploding hairspray?

Lastly, we’ll comment on your question about aerosol hairspray or deodorant cans exploding like bombs bursting in air. (Hey, it’s almost the 4th of July so we can wax a little patriotically poetic, can’t we?) While we’ve never personally heard of any cans exploding in transit it’s certainly not impossible. However, in the US the Department of Transportation (or DOT for short) dictates what requirements cans have to meet to be able to be safe to ship. The rule is that if the pressure in an aerosol can exceeds 180 to 200 pounds per square inch at 130 degrees F, then a special heavy-duty can must be used to ensure it won’t explode. If you’d like more details on aerosols and how they’re made, check out our 4 part series on Adorable Aerosols.

The Beauty Brains bottom line

We can all breathe a sigh of relief: all those Mary Kay cosmetic products being shipped out of Texas are probably perfectly fine.

What do YOU think? Have you ever received a cosmetic product that was ruined because it was exposed to too much heat? Leave a comment and share your thoughts with the rest of the Beauty Brains community.