Anti-pollution claims: how to test them?

Maria Coronado, Doctor in Chemical Engineering and Ingredients Associate Analyst with Euromonitor International, explains that efficacy testing is becoming a central focus for the trend as it develops.

“More educated consumers require more information and scientific proof from brands in order to purchase certain products, especially if they are carrying very specific claims such as anti-pollution,​” she says.

“The evaluation of the efficacy of antipollution cosmetic products on skin and hair is becoming crucial for the companies to support their claims. However, currently, there is no international agreement on standardized anti-pollution tests and different types of studies are currently available and used by the companies to demonstrate the antipollution claims.”​

Claims: many and varied​

The issues associated with pollution damage are numerous and varied, meaning the claim anti-pollution is a broad, umbrella term.

“It is widely accepted that most pollutants are detrimental to skin causing dryness, acne, dark spots, wrinkles, inflammation and skin aging,”​ she says. “There is no agreement on which pollution bio-markers are best to assess the efficacy of anti-pollution products.”​

What’s the right test?​

Coronado says that finding the right anti-pollution test for both raw ingredients and for finished products  is not an easy task, as different factors need to be taken into account. She notes the following potential hurdles:

• Finding the right environmental stressor or pollutant to test from urban dust, diesel combustion, and cigarette smoke such as Toxic gases – O3, SOx, NOx, PAH, PM, or even indoor pollutants
• The right pollutant to test depends to some extent on the specific region: climate, industrial activities, urban/rural area/traffic or any other kind of pollution/ skin type (sensitive or healthy) etc.
• Ethical considerations (in-vivo test using certain pollutants might not be allowed)
• Anti-pollution methods need to be standardized and reproducible: number of volunteers, reproducibility, and sensitivity of the analytic method to detect and measure the pollutant level accurately.

Potential pollution biomarkers for anti-pollution tests:​

When it comes to selecting the biomarkers to use for assessing the efficacy of products and ingredients, Coronado notes the following are all potential options:

• Skin lipids levels (triglycerides, free fatty acids (FFA), squalene, wax esters, ratio of FFA to squalene, ratio of Skin lipids levels FFA to waxes & glycerides in the skin (decrease when exposed to pollution)
• Cholesterol content (decreased when exposed to pollution as this antioxidant is mobilized to combat oxidative stress in the skin
• Vitamin E content (decrease when exposed to pollution)
• pH (increase when exposed to pollution)
• Lactic acid content (increase when exposed to pollution)
• Sebum secretion rate (increase when exposed to pollution)
• Advanced Glycosylation End Products content (increase when exposed to pollution)
• Malondialdehyde (MDA) is a lipid peroxidation marker (increase when exposed to pollution)
• Squalene monohydroperoxide (increase when exposed to pollution)
• Oxidized proteins (increase when exposed to pollution)
• Oxidative stress levels (increase when exposed to pollution)
• Interleukin IL1a (increase when exposed to pollution)
• Adenosine triphosphate
• Antioxidant and detoxification enzymes
• measuring transcutaneous pressure (in terms of oxygen and carbon dioxide)
• Tissue oxygenation (increase when exposed to pollution)
• Cytokeratin 10, filaggrin and loricrin on skin and hair
• Transcutaneous pressure(oxygen and carbon dioxide)
• Others such as elastin and collagen content, etc.

“There are a wide number of tests currently used by cosmetics companies to test the antipollution claims depending on the d pollution protection strategy or specific claim (anti-PM2.5 effects, detox, antioxidant, skin barrier, etc.) and the selected biomarker,​” she explains.

While the trend remains so broad in its scope, it appears that no conclusive efficacy test for anti-pollution trends is discernible. It remains up to brands and suppliers to set their own metrics and test accordingly.