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Is heat bad for beauty products?

Colo’s question…Hi, guys. It’s extremely hot right now where I live, and I read on a beauty blog that hot weather may affect the formulation of some cosmetics. They even suggested to keep them in the fridge during heatwaves, since cold is not supposed to alter the formulation. Is any of this true? 

The Beauty Brains respond:

Hey Colo. First of all, congrats on living somewhere warm. I’m in Chicago right now and the temperature is 11 below zero.  Yikes!

It is true that extreme heat can affect cosmetic products but I doubt your local heat wave is hot enough or long lasting enough to cause a problem for products that you’ve purchased. Here’s why:

How cosmetics are heat tested

Cosmetics are typically tested to ensure that they remain stable at elevated temperatures. The “torture test” is to put a product in an oven at 54C (130F) for a few weeks. Longer term testing is done at 45C (113F) for 3months and 37C (99F) for 6 months. Every company has their own test design but the end result is the same – products are evaluated to see how they react when the heat is on.

Unless your heat wave is exposing your products to temperatures above 100F for months at a time I don’t think you need to worry much. It’s more likely that the product was exposed to high temp BEFORE you bought it by sitting in an unairconditioned warehouse or in the back of a truck.

Of course the product type makes a difference as well. The oils used in fragrances can be very heat sensitive. Creams and lotions can separate after being stored at high temperatures for long periods of time. But heat won’t have much effect on solid products like bar soap or eye shadow. Here’s a list of products roughly ranked from most heat sensitive to least heat sensitive:

Heat sensitivity of cosmetic products

  • Perfume
  • Creams and lotions
  • “Creamy” shampoos, body washes, face cleansers and liquid foundations.
  • Lipsticks and eye liner pencils
  • Mascaras
  • Clear shampoos and body washes
  • Creamy cake makeup
  • Solid makeup (pressed powders)
  • Deodorants/antiperspirants
  • Bar soap

One final note: Since a bottle of perfume lasts a long time and since the ingredients are heat sensitive (and light sensitive too) that’s the one type of product that you might want to keep in the fridge.

Comments on this entry are closed.

  • nahla May 15, 2016, 9:43 am

    What about serum for eyebrows and aloe very gel and sunblock ? Thanks for your great article.

  • Teodora May 2, 2017, 6:47 am

    What about cosmetics with essential oils? I read that essential oils is temperature sensitive, more of them are unstable above 40 degrees Celsius.

    • Randy Schueller May 2, 2017, 8:44 am

      Yes, essential oils can be more temperature sensitive. (and light sensitive as well.)

  • Tami DiGiovanni June 13, 2017, 10:52 am

    I just purchased a 2.5% retinol cream which is beautifully packaged to protect the products consistency and formulation. However, it was delivered on a day that I was not home and sat in the mailbox in a 98 degree day for hours. I’m concerned about compromising of the retinol due to the heat exposure and would like your feedback. Thanks!

    • Randy Schueller June 14, 2017, 7:17 am

      Reputable cosmetic manufacturers test their products at high temperatures to ensure they remain stable. If it was only at 98 degrees for a few hours it’s probably fine.

  • Priscilla June 30, 2017, 8:32 pm

    Are face masks heat sensitive, (by face masks I am referring to the sheet types) -thank you, and your feedback will be much appreciated.

    • Randy Schueller June 30, 2017, 9:36 pm

      All cosmetics can be damaged by heat if the temperature is high enough. This is even more true if the mask contains specific active ingredients that are heat sensitive.

  • Jacqueline Davis August 13, 2017, 9:02 pm

    My car is 65°f I have my makeup in there till morning will it be ok for a few hours

  • Keven September 8, 2017, 10:36 am

    I can only store my products in the car when I’m at work.

    I use an airless plastic bottle for most of my products so that plastic can conduct heat if left outside. Would be best to store these things in glass since it conducts it less or at a slower rate from a I read.

    Plastic a beauty product that’s plastic inside a insulator of some sort like a yeti container or a glass bottle, this should suffice to a large degree. I assume at least.

    What are your thoughts?

    • Randy Schueller September 9, 2017, 3:13 pm

      I think you’d need some kind of insulated cooler to protect products that are stored in a very hot car. I doubt changing from plastic to glass will make much difference.

      • Keven September 10, 2017, 12:24 pm

        Going to drop the glass idea. The thicker the better, but I can’t find small glass containers with a wide thickness unless they’re huge and I’m only dealing with a 6-7″ bottle that needs to not heat up to hot car temps.

        The yetis or regular insulated water bottle containers mitigate outside heat to a large degree. I see a few that are touted to only dropping temps after 24 hours to 1-7 degrees, but that’s for a cold item. Not sure how they perform when deal with room temps in a car then the gradual increase overtime.

        They can fit in a glove box so I might give it a test. Maybe drop a few ice cubes in there for the hell of it.

  • Tentenation September 24, 2017, 11:07 pm

    The temperature of my room is always 30°, all year long. Would this affect my skincare product? And how long would it last? Thanks.

    • Randy Schueller September 25, 2017, 7:29 am

      Long term exposure to higher temperatures can shorten a product’s lifetime. It depends on the specific ingredients in the product.

  • ravi October 10, 2017, 1:54 pm

    my shampoo (forever living product) dropped in hot water ..temp of water was high .. is it ok to use it.. my shampoo was also heated

  • Verma February 7, 2018, 3:53 am

    Hi, I need to know the processing temperature of cosmetic product. do you know any product which goes beyond 100 degree centigrade.

    • Perry Romanowski April 3, 2018, 9:13 am

      There really aren’t any except maybe a few anhydrous products. Anything with water will stay below 100 C.

  • Susa Chapple April 23, 2018, 8:15 pm

    Hi, do all skin care manufacturer’s heat their products during the processing time? And is cold processing better for stabilizing ingredients?

    • Perry Romanowski June 15, 2019, 12:06 pm

      No they don’t all heat the products. It depends on the formulation. No cold processing is not better. In fact, it is usually harder and leads to less stable formulas.

  • Elizabeth Cagle August 21, 2019, 5:36 pm

    I had to move and most of my skincare, makeup was stored in an attic for over a year ,so it went from not to cold to not again should I throw it away and start over? I also had some cologne ,I sprayed some it still smells the same so is it ok ?

    • Perry Romanowski August 26, 2019, 1:17 pm

      Some of it will still be fine to use. You could use the smell test. If it smells bad, is a different color, or is separated, throw it away. Otherwise it will probably still be fine to use.

  • Adda September 19, 2019, 5:15 am

    Hi. I left my Freeman overnight mask in the car for about a week before I realized it. I live in hot country and its hot in the car during day. Is the heat can change the ingredients inside to harmful substances? I am quite worried to put it on my face. But what a waste to throw it because I just bought the product.

    • Perry Romanowski September 20, 2019, 12:57 pm

      Not harmful but probably that the product won’t work as you might expect.

  • Felicity December 18, 2019, 12:21 am

    Hi there, I bought body lotions (Victorias Secret) and the paxkage was left outside our doorstep with a temperature of 40 degrees celsius. I’m not sure how long it’s sitting there, I’m just concerned if it’s still safe to use? Thanks.