Why Are SLS and SLES Avoided in Cosmetics?

• SLS and SLES Production Process
• Contamination Risks and Health Impacts of SLS and SLES
• Use of SLS and SLES in Everyday Cosmetic Products
• Gentle Surfactant Options for Sensitive Skin

Sodium Lauryl Sulfate (SLS) and Sodium Laureth Sulfate (SLES) are types of anionic surfactants that function as cleansing and foaming agents. SLS and SLES are derived from palm oil, and their production process can have negative environmental impacts. Additionally, their sulfonate hydrophilic group is difficult to degrade in water, potentially leading to foam formation and posing risks to aquatic life.

SLS and SLES Production Process

SLS is produced through the hydrolysis of triglycerides, which are then reduced to lauryl alcohol before undergoing sulfonation and neutralization. The production of SLES involves an additional ethoxylation process, which carries the potential risk of forming a carcinogenic substance called 1,4-dioxane. The compound 1,4-dioxane is classified as a Category 2 carcinogen (suspected of causing cancer) by the International Agency for Research on Cancer (IARC) under Group 2B carcinogens. 

The International Cooperation on Cosmetics Regulations (ICCR) and the Scientific Committee on Consumer Safety (SCCS) of the European Commission state that the amount of 1,4-dioxane in cosmetic products is considered safe for consumers at levels less than or equal to 10 ppm. In Indonesia, according to the Indonesian Food and Drug Authority (BPOM) Regulation No. 12 of 2019 on Contaminants in Cosmetics, Article 5, Paragraph 3 states that the chemical contaminant 1,4-dioxane is limited to no more than 25 mg/kg (25 ppm) in a cosmetic formulation. 

Contamination Risks and Health Impacts of SLS and SLES

Since 1,4-dioxane is water-soluble, it is difficult to remove and cannot be detected by the naked eye. As a result, many choose to avoid using SLES to ensure product safety from carcinogenic contaminants. The health effects of SLS and SLES have also been widely debated. SLS is known to cause skin and eye irritation in some individuals, particularly those with sensitive skin. This has led to an increased demand for products labeled “SLS-free.” Although SLES is considered milder, it still carries a risk of irritation for some users. 

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Use of SLS and SLES in Everyday Cosmetic Products

In cosmetics, SLS and SLES are used as cleansing and foaming agents, not only in soaps but also in shampoos, conditioners, toothpaste, makeup removers, shaving creams, and other products. The strong cleansing ability of these surfactants makes them widely used in everyday products. Their cost-effectiveness and superior performance make them a top choice for manufacturers. 

However, the production process and household waste of SLS and SLES negatively impact the environment, leading to their avoidance. SLS is more difficult to degrade than SLES, which can result in contamination of terrestrial (edaphic) and aquatic environments. There are several alternative surfactants that are gentler on the skin and more environmentally friendly. 

Gentle Surfactant Options for Sensitive Skin

Coconut-based surfactants, such as Cocamidopropyl Betaine, Sodium Cocoyl Isethionate (SCI), and Decyl Glucoside, are safe for use in baby products. These surfactants are milder on the skin and produce less foam compared to SLS/SLES. The use of SLS/SLES is still permitted, provided that its concentration follows regulatory limits. 

To minimize side effects, especially for individuals with sensitive skin conditions such as eczema, it is recommended to use rinse-off products with a concentration of no more than 1%. The severity of side effects may vary from person to person, depending on dosage, age, and individual tolerance levels.

Make sure the cosmetic products you use or produce have gone through a process of testing the content of ingredients and safety according to applicable standards, in order to protect consumers and maintain trust in your products.

Author: Delfia
Editor: Sabilla Reza

References:

Badan POM (BPOM). 2019. Peraturan Badan Pengawas Obat dan Makanan Nomor 12 Tahun 2019 Tentang Cemaran dalam Kosmetika. Diakses pada 8 Oktober 2024. Dapat diakses melalui tautan : https://notifkos.pom.go.id/upload/informasi/20190923110116.pdf.

FDA (Food and Drugs Administration). 2022. 1,4-Dioxane in Cosmetics: A Manufacturing Byproduct. Diakses 13 September 2024. Tersedia pada https://www.fda.gov/cosmetics/potential-contaminants-cosmetics/14-dioxane-cosmetics-manufacturing-byproduct.

Scientific Opinion on The Report of the ICCR Working Group: Considerations on Acceptable Trace Level of 1,4-Dioxane in Cosmetic Products,” 15 December 2015, SCCS/1570/15.

Wilbur S, Jones D, Risher JF, et al. 2012. Toxicological Profile for 1,4-Dioxane. Atlanta (GA): Agency for Toxic Substances and Disease Registry (US).