HEAT AND SUNLIGHT
Heat and light can change the chemicals in your products effecting how they work; this can even create an environment for bacteria to grow! Some ingredients and products are more affected by high temperatures than others, like these:
Extra sensitive products and ingredients:
• Products containing vitamin C (look for the ingredient ascorbic acid)
• Anti-ageing creams (look for the ingredient retinol)
• Acne fighting products (look for the ingredient benzoyl peroxide)
• Self-tanners and whitening products (look for the ingredient DHA)
• All preservative-free products (anything organic)
Moderately sensitive products:
• Lipsticks (direct sunlight can cause them to melt)
• Brushes (can absorb moisture and bacteria)
• Powder products (UV rays can damage pigment and fade colours)
• Consider keeping these products on the lowest shelf away from direct sunlight, steam or heating.
Oxidation is the chemical change that happens when a formula comes into contact with air. If your makeup or skin care products oxidise, they can change colour, dry out or get clumpy – in short, they won’t do their job.
Extra sensitive products:
• Organic creams
• Natural oils
• Mascaras and liquid eyeliners
• Always close bottles immediately after using them and be careful when you’re in the shower as steam can be particularly damaging.
• Always wash your hands before application to avoid bacteria getting into your products.
• Store sensitive products in the dark (like in a black linen bag or in dark bottles).
For some products, cold temperatures can help slow the separation process of key ingredients and make them last longer. Refrigeration can limit bacterial growth, but won’t stop it completely.
Products to temporarily refrigerate:
• Fine fragrances (if you want to preserve them for more than a year)
• Nail polish (but apply at room temperature)
• All preservative-free/organic products
Products that you could temporarily refrigerate:
• Moisturisers, eye creams, serums, and toners (particularly nice when the weather’s warm!)
• Recognise that refrigeration does not mean preservation for all products (if it does not contain preservatives, it’s unlikely to have a very long shelf life).
• Know that skin care products are designed to withstand normal changes in temperature, but not long-term hot or cold storage— so keeping your products in your fridge for an extended time can actually reduce their lifespan and stability.
• Realise that jar packaging is more likely to carry bacteria. Why? Because you apply it with your fingers. Store these products in a cool place to kill off germs.
• Keep in mind that if you keep anything that's not food in your fridge, always make sure it's well-sealed, not only for safety, but for hygiene too.