This Is What Really Happens When You Leave Makeup In The Car

We always recommend having an emergency beauty kit close by for midday touchups, post-office dinner dates and just for looking your best at all times. We often keep ours in the car (not the best idea in sunny LA, we know), which got us wondering if that has any effect on our makeup and skincare products. To find out, we asked co-owner and president of Spatz Laboratories, Laura Nelson, who knows everything there is to know about the chemistry of beauty products. Discover what really happens when you leave your makeup bag in your car (hint: you may want to start carrying it with you).

Contents Under Pressure

How do powdered and liquid foundations react when left in a hot car?

“Generally speaking, all powders and most liquids are fine in the heat. If the product is visibly separated, try to shake it to mix it back together. If that doesn't work refrain from using the product as it could potentially affect the skin differently or change the quality of coverage.”

Do shadow sticks and cream products get ruined in the heat?

“Some stick and cream products can melt or separate to the point where they no longer offer the same application or performance. There is nothing in makeup that reacts under heat to create a toxic chemical, but it can compromise the quality.”

Can sunlight change the shade of my colored makeup?

"Storing makeup in direct sunlight is less than optimal as it may result in the formula fading, depending on shade and colorants used."

Does heat have an effect on skincare products?

“Skincare products can be vulnerable to heat in several ways. Elevated temperatures may deactivate active ingredients, preservatives and fragrances in lotions and sunscreens.”

Are there any other storage places that may alter your beauty products?

“Some products may be vulnerable to yeast or mold growth if kept in hot and humid conditions, such as those found in the home bathroom. For any formula that contains water in the ingredient list, adding moisture to the product can overload the preservation system and cause microbial growth. Examples are shampoos, conditioners or cleansers that are kept in the shower and may get water in them by accident.”