How to Properly Formulate Gentle Cleaning Agents for Sensitive Skin: Answers to 5 Key Questions

Photo: engin akyurt / Unsplash

Developing cleaning products for sensitive skin places increased demands on manufacturers – from raw material selection to stability and safety testing. Customers often wonder how to achieve effective cleaning without irritation, which surfactants are suitable for children’s skin, or how to properly set the pH of the final product. In this article, we focus on the five most common questions posed by the cosmetics industry and provide specific recommendations for formulating gentle yet effective products.

1. Which raw materials are key for gentle cleaning products?

Gentle cleaning products for sensitive skin must combine efficacy with minimal irritant potential. The foundation consists of mild surfactants that effectively remove impurities without disrupting the skin barrier. Among the most suitable are amphoteric surfactants (e.g., cocamidopropyl betaine) or nonionic surfactants (e.g., fatty alcohol ethoxylates), which exhibit low irritancy and good skin compatibility. It is important to avoid aggressive anionic surfactants such as sodium lauryl sulfate (SLS), which can cause irritation and dryness.

Another key component is emollient and protective substances, such as polyols (glycerin, sorbitol) or plant oils (e.g., almond, jojoba). These ingredients help maintain skin hydration and form a protective film that prevents moisture loss. For sensitive skin, it is also advisable to include substances with anti-inflammatory and soothing effects, such as panthenol, allantoin, or extracts from chamomile or aloe vera. The correct formulation should be tested for dermatological tolerance according to applicable standards and certified as hypoallergenic.

2. How to Ensure Low Irritancy and Hypoallergenicity?

Low irritancy and hypoallergenicity are fundamental requirements for cleaning products designed for sensitive skin. The first step is selecting raw materials with proven low irritancy that comply with REACH and CLP regulations. It is also important to minimize the number of ingredients in the formulation to reduce the risk of allergic reactions. Each new component should be carefully tested for compatibility with other ingredients and the skin.

To verify hypoallergenicity, dermatological tests such as patch tests are conducted to evaluate the skin's reaction to the product. Additionally, it is advisable to perform tests on sensitive skin under dermatological supervision. Manufacturers should ensure that their products do not contain known allergens, such as certain preservatives (e.g., methylisothiazolinone) or fragrances. Instead of synthetic fragrances, natural essential oils in low concentrations can be used, but these must also be tested for allergenicity.

Photo: ibnu ihza / Unsplash

3. What is the optimal pH for gentle cleaning products?

The optimal pH of a cleaning product for sensitive skin should be as close as possible to the skin's natural pH, which ranges between 4.5 and 5.5. This slightly acidic environment helps maintain the skin's protective barrier and prevents the growth of harmful microorganisms. Products that are too alkaline (pH above 7) can disrupt the skin's natural balance, causing dryness and irritation, while products that are too acidic (pH below 4) may irritate or damage the skin.

When formulating, it is important to use pH regulators that allow precise adjustment of the desired value. Lactic acid or citric acid are commonly used substances for lowering pH, while sodium hydroxide or triethanolamine are used to increase it. The pH value should be measured using standard methods and regularly monitored during production to ensure product consistency. Manufacturers should state the pH on the packaging so that customers with sensitive skin can easily select a suitable product.

4. What testing is essential before launching a product on the market?

Before launching a gentle cleaning product on the market, it is essential to conduct a series of tests to verify its safety, efficacy, and compatibility with sensitive skin. The basic test is a dermatological assessment, which includes patch tests on a group of volunteers with sensitive skin. These tests evaluate whether the product causes irritation, redness, or allergic reactions. Additionally, microbiological stability tests are performed to verify that the product resists contamination by bacteria or mould during storage.

Another important step is efficacy testing, which verifies whether the product meets the declared properties, such as the ability to remove dirt or maintain skin hydration. These tests are conducted using standard testing methods, for example, with model soils or by measuring skin hydration before and after product use. Manufacturers should also consider testing for environmental impact, especially if the product contains biodegradable ingredients. All tests should be documented, and the results should be available to regulatory authorities and customers.

Photo: Camille Brodard / Unsplash

5. How to balance efficacy and gentleness in a cleaning product formulation?

Efficacy and gentleness are two sides of the same coin – without the right balance, a product either cleans insufficiently or causes excessive irritation. The key lies in combining mild surfactants with effective yet non-aggressive additives. For example, anionic surfactants like lauryl sulfates (SLS/SLES) can be replaced with a blend of amphoteric (e.g., cocamidopropyl betaine) and nonionic surfactants (e.g., alcohol ethoxylates), which provide a synergistic effect: they reduce the surface tension of water while minimizing irritation. It is also important to optimize the concentration – too low fails to remove dirt, while too high increases the risk of irritation. Typically, the range is 5–15% of active substances, with the lower end recommended for sensitive skin.

Another factor is the addition of ingredients that enhance skin comfort without compromising efficacy. Hydrating components such as glycerin, panthenol, or allantoin help restore the skin’s lipid barrier, while thickeners (e.g., xanthan gum) improve texture and prolong contact with dirt. To remove grease or stubborn stains, a mild solvent like ethanol or propylene glycol can be used, but at concentrations of up to 5% to avoid drying out the skin. It is always essential to test the final formulation on real dirt samples, as interactions between ingredients can affect overall performance.

6. Which preservative systems are suitable for gentle cleaning agents?

Preservation is essential to ensure the microbiological stability of a product, but in gentle cleaning agents, it must be chosen with safety and compatibility for sensitive skin in mind. Traditional preservatives like parabens or formaldehyde-releasing agents are effective but may trigger allergic reactions. Alternatives include milder systems, such as blends of organic acids (benzoic acid, sorbic acid) combined with chelating agents (EDTA), which enhance their efficacy. These substances are effective at a pH below 5.5, which is also beneficial for maintaining the skin’s optimal pH.

Another option is natural preservatives such as rosemary extracts, grapefruit seed extracts, or essential oils (e.g., tea tree oil), which have antimicrobial properties. However, their effectiveness is lower and they require higher concentrations, which can affect the sensory properties of the product or trigger allergies. For sensitive skin, multifunctional preservatives like phenoxyethanol are often used, as it is effective even at low concentrations (up to 1%) and has a low irritation potential. It is always necessary to verify the stability of the preservative system in the specific formulation, as interactions with other ingredients (e.g., surfactants) can reduce its effectiveness.

7. How to Communicate Product Sustainability to Customers While Complying with Regulatory Requirements?

Communication of sustainability must be based on verifiable facts to avoid misleading claims. According to CLP and GHS regulations, it is necessary to list all ingredients that may pose a risk (e.g., allergens, irritants), even if they are present in low concentrations. For sustainable products, it is advisable to emphasize the absence of aggressive substances (e.g., "SLS/SLES-free", "paraben-free") or the presence of beneficial ingredients (e.g., "with panthenol for hydration"). However, it is important to avoid unverified claims such as "100% natural" or "hypoallergenic" unless they are supported by clinical tests.

Regulatory requirements also demand proper labeling of packaging, including hazard symbols, safe use instructions, and a list of ingredients according to INCI. For B2B customers, it is also crucial to provide technical data sheets and safety data sheets (SDS), which contain detailed information on composition, physico-chemical properties, and safety measures. Transparent communication builds trust and helps customers make informed decisions. In the case of certifications (e.g., Ecocert, COSMOS), they can be mentioned, but always with reference to the specific standards that the product meets.

Need Help with Formulation?

Every raw material supplied by GCG Group is accompanied by detailed safety data sheets and technical specifications. Our experts will be happy to assist you in selecting suitable components and optimizing the formulation for your specific needs. Contact us – or browse our catalog of over 1,300 products right away.