Purpose and Importance of Preservation
Purpose and Importance of Preservation
Cosmetics encompass everything from moisturizers and makeup to shampoos and serums. They contain water-based ingredients that create an ideal breeding ground for harmful microorganisms. Without effective preservation, cosmetics could become rancid, discolored, or odorous. Appropriate preservation is essential for ensuring the shelf life, aesthetics, and safety of cosmetic formulations.
The damaging effects extend up to:
- Product spoilage: Bacteria and fungi can produce enzymes that break down cosmetic ingredients. This causes the product to change color, develop an unpleasant odor, or become slimy.
- Product contamination: Microorganisms can contaminate cosmetics with harmful toxins or allergens. This can lead to skin infections, eye infections, and other health problems.
- Reduced product efficacy: Microorganisms can interfere with the active ingredients in cosmetics. This makes them less effective.
- Short shelf life: Microorganisms can multiply in cosmetics. This causes the product to spoil.
Role of Preservatives in Preventing Microbial Growth
Role of Preservatives in Preventing Microbial Growth
Preservatives play a crucial role in preventing microbial growth in cosmetic products. Their primary function is to inhibit or slow down the growth of microorganisms that contaminate or spoil these products. Find out the role of preservatives in preventing microbial growth:
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Microbial Contamination Prevention:
Cosmetics are often exposed to air, skin, and various external contaminants during use. Microorganisms present in these environments can find their way into cosmetic products. Preservatives act as a barrier against such contamination by hindering the growth and reproduction of microorganisms.
- Prolonging Shelf Life:
By preventing or slowing down microbial growth, preservatives extend the shelf life of cosmetics. This ensures that products remain safe and effective for a longer duration. Thus, reducing the likelihood of consumers using products that have gone bad.
- Product Safety:
Microbial contamination in cosmetics can lead to the development of harmful bacteria or fungi. Using contaminated products on the skin or near the eyes can result in skin irritations, infections, or even more serious health issues. Preservatives help protect consumers from these health risks.
- Product Integrity:
Preservatives help maintain the physical and chemical integrity of cosmetics. They prevent undesirable changes in color, texture, and odor that may occur as a result of microbial activity. This is particularly important in maintaining the sensory attributes of products.
- Enhanced Product Performance:
Preservatives contribute to the efficacy of cosmetics. In formulations with water-based ingredients, preservatives can ensure that active compounds remain stable and effective over time delivering the intended benefits to the user.
- Compliance with Regulatory Standards:
Many countries and regions have regulations that cosmetics need to be safe for consumer use. Using preservatives is often a legal requirement to meet these standards. Cosmetic manufacturers must adhere to these regulations to ensure their products can be sold in the market.
- Product Consistency:
Preservatives maintain the consistency of cosmetic formulations from batch to batch. Without preservatives, variations in microbial contamination levels could occur. This can lead to inconsistent product quality and safety.
- Protection of Water-Based Formulations:
Many cosmetic products contain water as a key ingredient. The presence of water makes them particularly susceptible to microbial growth. Preservatives are essential in preventing the proliferation of microorganisms in these water-based formulations.
Types of Cosmetic Preservatives
Types of Cosmetic Preservatives
Based on their chemistry, different classes of preservatives work differently. The table below lists some common types of preservatives used in cosmetic formulations, their characteristics, and examples.
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Preservative Type
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Characteristics
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Effective against
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Recommended End-Use Percentage
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Parabens
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- Effective against a wide range of microorganisms
- Good stability in a variety of formulations
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Bacteria and molds
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0.8% - 1.0%
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Phenoxyethanol
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- Relatively low cost
- Broad-spectrum efficacy
- Stable in a wide pH range
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Bacteria, yeasts, and molds
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0.5% - 1.0%
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Benzyl Alcohol
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- Compatible with a range of cosmetic ingredients
- Mild, non-irritating to the skin
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Bacteria and yeasts
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1.0% - 2.0%
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Formaldehyde Releasers
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- Suitable for natural and organic formulations
- Long-lasting preservation
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Bacteria and fungi
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Varies (per manufacturer)
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Sorbic Acid
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- Often used in combination with other preservatives
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Molds, yeasts, and some bacteria
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0.1% - 1.0% (typically)
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Benzoic Acid
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- Suitable for pH levels between 4 and 6
- Compatible with a wide range of cosmetic ingredients
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Yeasts and molds
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0.1% - 0.8% (typically)
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Ethylhexylglycerin
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- Works best in slightly acidic formulations
- Acts as a co-preservative to enhance antimicrobial activity of other preservatives
- Offers skin conditioning properties
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bacteria, yeasts, and molds in combination with phenoxyethanol
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0.5% - 2.0%
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Caprylyl Glycol
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- Suitable for leave-on and rinse-off products
- Hydrating and skin-conditioning properties
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Bacteria, yeast, and molds
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0.2% - 1.0%
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Sodium Benzoate
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- Compatible with a variety of cosmetic formulations
- Widely used as a food preservative and in cosmetics
- Suitable for water-based and pH-adjusted products
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Yeasts and molds
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0.1% - 0.8%
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Potassium Sorbate
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- Enhances the shelf life of emulsions and creams
- Commonly used in conjunction with sodium benzoate
- Ideal for preservation of water-based products
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Molds, yeasts, and some bacteria
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0.15% - 0.5%
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Natural Extracts and Blends
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- Suitable for natural and organic cosmetics
- Use of botanical extracts like rosemary, grapefruit seed, etc.
- Trend toward eco-friendly and consumer appeal
- Usually used in combination with other preservatives for synergistic effects
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Depends based on the combination preservative
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Varies (per manufacturer)
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Table 1: Types of preservative chemistries
Compatibility of Preservative Chemistries
⇨ Parabens with Phenoxyethanol
Parabens are often used in combination with phenoxyethanol. This blend offers a broad-spectrum antimicrobial effect. Parabens are effective against a wide range of microorganisms. Examples of paraben include methylparaben and ethylparaben. While phenoxyethanol enhances the preservative system's performance. |
⇨ Sorbic Acid with Potassium Sorbate
Sorbic acid and potassium sorbate are often used together. Sorbic acid is effective against molds. Potassium sorbate targets yeasts. This combination helps inhibit the growth of a broader range of microorganisms.
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⇨ Benzyl Alcohol with Dehydroacetic Acid
Benzyl alcohol is effective against bacteria and yeasts. Dehydroacetic acid is used in combination with benzyl alcohol. It extends its effectiveness and offers a broader spectrum of protection.
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⇨ Phenethyl Alcohol with Ethylhexylglycerin
Phenethyl alcohol is a gentle and effective preservative against bacteria and molds. When combined with ethylhexylglycerin, it enhances the preservation of the product. It also provides skin conditioning benefits, such as skin conditioning.
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⇨ Natural Extracts with Phenoxyethanol
Natural extracts are sometimes used alongside synthetic preservatives like phenoxyethanol. This combination combines the antimicrobial properties of phenoxyethanol with the antioxidant benefits of natural extracts. Rosemary or grapefruit seed extract are some examples of natural extracts. |
⇨ Parabens with Ethylhexylglycerin
This combination enhances the preservation system. Ethylhexylglycerin is a co-preservative. It can work together with parabens to improve their efficacy.
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⇨ Sodium Benzoate with Potassium Sorbate
These preservatives are often used together, especially in natural and organic cosmetic formulations. This combination targets yeasts and molds and is effective in water-based products.
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Factors to Consider When Selecting Preservatives
Factors to Consider When Selecting Preservatives
Selecting the most appropriate preservative system is one of the most important considerations when developing any cosmetic or personal care product formulation. When evaluating preservative options, formulators weigh several key factors including broad-spectrum activity, toxicity profile, pH and temperature stability, interactions with other ingredients, and cost in order to arrive at an optimal blend for preserving the quality and integrity of the product. Let’s review all these factors in detail:
Cosmetic Product Type
The type of cosmetic product is an important factor to consider when choosing an appropriate preservative system. This is because different product types have different formulation characteristics that affect preservative efficacy and stability. For example,
- Emulsions like creams and lotions typically require a broad-spectrum preservative blend because their water phase provides an optimal environment for fungal, yeast, and bacterial growth
- Anhydrous products like powders and lipsticks have less microbial growth risk and may only require anti-fungal paraben preservatives
- Products with higher pH levels, like shampoos and cleansers, limit the use of pH-dependent preservative options
- Products containing natural botanical ingredients may require extra care to avoid preservative interactions
Considering the cosmetic product type and its unique formula landscape is essential for matching it with a preservative system that offers maximum protection against spoilage.
Browse the preservative grades used in various applications:
Microbial Risks Associated with the Product
The types of microbial contaminants likely to be risks for a given cosmetic product should guide preservative selection. Formula components like water activity, nutrients, and pH affect the growth of different microorganisms.
- Bacteria such as Pseudomonas aeruginosa and Staphylococcus aureus thrive in moist emulsions and can cause rancidity and odor
- Yeasts like Candida albicans prefer higher pH products. Mold species including Aspergillus niger are risks in anhydrous powders
Consumers introduce bacteria from their fingers and applicators during use. Evaluating product microbiology helps determine which organisms a preservative system must control. High-risk products may require broad-spectrum preservative blends. Low-risk products may need only light preservation. Considering product microbial risks allows matching preservatives that provide sufficient protection while minimizing unnecessary preservative load.
pH and Compatibility
The pH of a cosmetic formula plays a key role in preservative effectiveness and should guide selection.
- Many common preservatives like parabens, formaldehyde donors, and phenoxyethanol work best at pH levels below 5.5.
- Higher pH products require preservatives effective in alkaline conditions, like some multifunctional acids or hydantoin derivatives.
- Using a preservative outside its optimal pH range can result in inadequate microbial control and spoilage.
- The pKa of an acidic preservative indicates the pH level where 50% of the molecules are in their active, undissociated form. Lower pKa equals greater acidity and antimicrobial efficacy in higher pH products.
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Preservative
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Optimal pH Range
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Parabens
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4.5-6.0
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Phenoxyethanol
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6.0-8.0
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Benzoic acid
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2.5-4.5
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Sorbic acid
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3.5-6.0
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Dehydroacetic acid
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3.0-7.0
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Table 2: Optimal pH Range
Formulators must match preservative pH compatibility to the finished product pH to ensure sufficient antimicrobial activity is maintained. Adjusting formula pH should be considered if the desired preservative works best at another range.
Checking the pH of preservative formulations (Source: LisaLise Blog)1
Regulatory Requirements and Restrictions
Preservatives must meet the safety and usage standards set by various regulatory bodies in the regions where a product will be marketed.
European Union (EU)
The EU has one of the strictest cosmetic regulations in the world. The Cosmetics Regulation EC No. 1223/2009 regulates the use of preservatives in cosmetic products marketed in the EU. Annex V2 of the regulation contains a list of all substances that can be used as preservatives in cosmetics, along with their maximum concentration limits and other restrictions.
The EU regularly updates its list of preservatives to ensure that only safe and effective substances are allowed on the market. In 2023, the EU banned the use of triclosan in mouthwash and restricted the use of genistein, daidzein, kojic acid, alpha-arbutin, and arbutin in cosmetic products.
United States (US)
The US Food and Drug Administration (FDA) regulates the safety of cosmetic products and ingredients, but it does not have a specific list of approved preservatives. Instead, the FDA relies on cosmetic manufacturers to ensure that the products they put on the market are safe. The FDA has issued guidance documents on the safety and efficacy of certain preservatives3, but these documents are not legally binding. Manufacturers are responsible for testing their products to ensure that they are safe and that the preservatives they use are effective.
Other Countries
Many other countries have their own regulations governing the use of preservatives in cosmetic products. Some of these regulations are similar to the EU's, while others are more or less strict.
For example,
- Canada's Cosmetic Ingredient Hotlist prohibits the use of certain preservatives in cosmetic products, including formaldehyde, toluene, and parabens.
- Japan's Cosmetics Act also prohibits the use of certain preservatives, including formaldehyde, toluene, and mercury.
Discover the preservative range complying with the following regulations and certifications:
Cosmetic manufacturers should carefully review the regulations of each country where they plan to sell their products to ensure that they are in compliance.
Trends in Cosmetic Preservative Regulations
There is a growing trend towards stricter cosmetic preservative regulations around the world. This is due to concerns about the safety of certain preservatives, such as parabens and formaldehyde.
Here are some of the latest trends in cosmetic preservative regulations:
➣ Restrictions on parabens: Parabens are a group of preservatives that are widely used in cosmetic products. However, there is growing concern about the safety of parabens, and many consumers are looking for paraben-free products. Some countries, such as Denmark4 and Norway, have banned the use of certain parabens in cosmetics.
➣ Restrictions on formaldehyde releasers: Formaldehyde releasers are a group of preservatives that release formaldehyde when they are applied to the skin. Formaldehyde is a known carcinogen, and many countries are restricting the use of formaldehyde releasers in cosmetics. For example, the EU has banned the use of certain formaldehyde releasers in cosmetics.
➣ Rise of natural preservatives: Natural preservatives, such as benzoic acid and sorbic acid, are becoming increasingly popular. Natural preservatives are derived from plants and other natural sources, and they are generally considered to be safe and non-irritating.
Global Cosmetic Preservatives Market (Source: Global Market Insights)5
Overall, the global trend is towards stricter cosmetic preservative regulations and a growing demand for cosmetic products that are free of harsh chemicals and artificial ingredients.
Explore the preservatives portfolio featuring some of the current trends:
Consumer Preferences for Natural or Chemical Preservatives
Consumer demand for either natural or synthetic preservative systems is an important market-driven consideration. Many consumers have concerns over certain controversial synthetic preservatives like parabens and prefer natural alternatives perceived as safer.
Common natural preservatives include essential oils, organic acids, and plant extracts. However, natural does not automatically equal safer toxicity profiles.
Synthetic preservatives are highly effective at lower use levels with well-studied safety data.
Yet the “chemical-free” trend persists among green cosmetic consumers. Understanding customer preferences, whether founded or not, guides preservative choices that align with a brand's natural or clinical positioning.
Market research provides insight into what consumers value most - microbiological safety, toxicity concerns, or preservative origins. Ultimately, effective preservation of cosmetics relies on appropriate synthetic and natural preservative blends to satisfy both product needs and consumer values.
Preservative Efficacy and Testing
Preservative Efficacy and Testing
Ensuring a preservative system provides adequate protection against microbial growth is critical for cosmetic quality and safety. Preservative efficacy testing is performed to confirm that a formulated product containing a preservative will have the necessary antimicrobial effectiveness.
Standardized laboratory challenge tests are used to determine the minimum inhibitory concentrations (MIC) and measure preservative retention over time. Common challenges include bacteria like Pseudomonas aeruginosa, yeasts such as Candida albicans, and molds including Aspergillus brasiliensis.
Preservatives must prevent significant increases in microbial count in inoculated formulas for a specified duration. Additional studies assess preservative efficacy in accelerated aging tests and under consumer use conditions. Performing rigorous preservative efficacy testing during development validates the appropriateness of a preservative system. It also helps gain regulatory product approval.
Methods for Determining Efficacy of Preservative
There are two main methods for determining preservative efficacy in cosmetics:
- Challenge testing
- In-use testing
Challenge Testing
In challenge testing, a known number of microorganisms are inoculated into the cosmetic product. Then the product is incubated at a specific temperature for a period of time. The number of surviving microorganisms is then counted. This determines how effective the preservative system is at inhibiting microbial growth.
Challenge testing can be performed using a variety of different microorganisms. The most common test organisms are:
- Bacteria: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa
- Fungi: Candida albicans, Aspergillus niger
- Yeasts: Saccharomyces cerevisiae
Challenge testing should be performed under controlled conditions to ensure that the results are accurate and reproducible. The test should also be performed on a variety of different product samples to ensure that the preservative system is effective throughout the product's shelf life.
Challenge tests can be performed at a variety of different temperatures. The most common temperature is 32.5°C, which represents the average human body temperature. The incubation time for challenge tests typically ranges from 7 to 28 days. After the incubation period is complete, the product is sampled and tested for microbial growth. The results of the challenge test are used to determine the preservative efficacy of the product.
A product is considered to have passed a challenge test if the number of surviving microorganisms is below a certain threshold. The threshold value for challenge tests is typically 100 CFU/g or CFU/mL. This value can vary depending on the type of product and the intended use of the product.
Challenge tests are an important tool for assessing the preservative efficacy of cosmetic products. They help to ensure that cosmetic products are safe and effective for consumers.
Here are some of the benefits of using challenge tests:
- Challenge tests are a more realistic assessment of preservative efficacy than in vitro testing methods, such as the disc diffusion test and the minimum inhibitory concentration (MIC) test.
- Challenge tests assess the preservative efficacy of a product against a variety of different microorganisms, including bacteria, fungi, and yeasts.
- Challenge tests can be used to assess the preservative efficacy of a product under a variety of different conditions, such as different temperatures and storage times.
Challenge Testing (Source: Microchem Laboratory)6
In-use Testing
It is used to determine how effective a preservative system is at inhibiting microbial growth in real-world conditions. In in-use testing, the cosmetic product is used by a group of consumers for a period of time. The product is then collected from the consumers and tested for microbial growth.
In-use testing is a more complex and expensive method than challenge testing. But the former provides more realistic data on the preservative efficacy of a cosmetic product.
In-use Testing (Source: ADSL Limited)7
In addition to challenge testing and in-use testing, there are a number of other methods that can be used to assess the preservative efficacy of cosmetic products. These methods include:
- Preservative efficacy testing (PET): Determines the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of a preservative against a test organism.
- Time-kill assays: Determines how quickly a preservative kills a test organism.
- Antimicrobial resistance testing: Determines whether a test organism is resistant to a particular preservative.
The best method for determining preservative efficacy in a cosmetic product will depend on a number of factors, including the type of product, the preservative system used, and the intended use of the product.
The Importance of Stability Testing
Stability testing is the process of evaluating the stability of a cosmetic product over time.
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It is an important part of the cosmetics development and manufacturing process. It ensures that the product is safe and effective throughout its shelf life.
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It is also important for cosmetics preservation. It ensures that the preservative system effectively prevents microbial growth.
Stability testing should be performed on a variety of different product samples to ensure that the product is stable throughout its production batch.
There are two main types of stability testing:
- Real-time stability testing: This type of testing involves storing the product at the expected conditions of use and testing it at regular intervals over its shelf life.
- Accelerated stability testing: Accelerated stability testing involves storing the product at elevated temperatures and humidities to simulate the effects of long-term storage. It is a faster and less expensive way to assess the stability of a product. It is important to note that the results of accelerated stability testing cannot be directly extrapolated to real-world conditions.
Parameters Evaluated During Stability Testing
✓ Appearance: The appearance of the product should remain unchanged throughout its shelf life.
✓ Odor: The odor of the product should remain unchanged throughout its shelf life.
✓ pH: The pH of the product should remain within a specified range throughout its shelf life.
✓ Viscosity: The viscosity of the product should remain within a specified range throughout its shelf life.
✓ Microbiological quality: The product should remain free of harmful microorganisms throughout its shelf life.
If the product fails any of the stability tests, we may need to modify the formulation or strengthen the preservative system.
Watch this 3-min video to get an in-depth knowledge about preservatives and view how Clariant is moving with the regulatory aspects of the industry and new scientific protocols.
Alternatives to Traditional Preservatives or Self-Preservation
Alternatives to Traditional Preservatives or Self-Preservation
There are a number of materials that can act as alternatives to traditional preservatives in cosmetics. Some of the most common alternative preservatives include:
Essential Oils
Essential oils are concentrated extracts of plants that have antimicrobial properties. Some common essential oils that are used as preservatives in cosmetics include:
Surfactants
Surfactants lower the surface tension of liquids but they can also have antimicrobial properties. Some common surfactants that are used as preservatives in cosmetics include:
Chelating Agents
Chelating agents, known for their metal-binding prowess, are chemical compounds adept at forming strong bonds with metal ions. Metal ions can be essential for the growth of microorganisms, so chelating agents can help to prevent microbial growth in cosmetics.
Some common chelating agents that are used as preservatives in cosmetics include:
It is important to note that no single alternative preservative is as effective as traditional preservatives, such as parabens and phenoxyethanol. However, by using a combination of alternative preservatives, it is possible to create cosmetic products that are safe and effective.
Benefits of Using Alternative Preservatives
- They are generally considered to be safer and less irritating than traditional preservatives.
- They are often more biodegradable than traditional preservatives.
- They can help to create cosmetic products that are more appealing to consumers who are looking for natural and organic products.
It is important to note that alternative preservatives may not be as effective as traditional preservatives, and they may require more careful formulation.
Formulation Guidelines
Green Alternatives for Cosmetic Preservation
Green Alternatives for Cosmetic Preservation
Nowadays natural antimicrobial systems used in cosmetic formulations need to meet several requirements:
- Efficient
- Compatible with the other ingredients in the formula
- Safe for the skin
- Compliant with the regulatory authorities
- Renewable and responsibly sourced
The Big Dilemma Formulators Face Today
The major dilemma that cosmetic formulators face today is whether to use:
Conventional preservatives that have a low trust score among consumers or follow the free-from trend driven by consumers' fears. The dilemma is also aggravated by the shrinking list of approved preservatives. This makes it more challenging to choose a preservative with long-term longevity.
Luckily over the years, the marketplace has developed different solutions through the use of multi-functional ingredients. These types of ingredients have a primary function but also other additional antimicrobial properties. For example, emollient or surfactant.
The use of these ingredients is more complex than conventional preservatives. This is because they need to be blended to achieve broad-spectrum protection in different applications. However, the upside of the bespoke mix-and-match approach behind multi-functionals is that they can be used in combination with conventional preservatives to reduce use levels for extra mildness. It does not have to be one approach or the other.
Consumers in the Driving Seat
Consumers are becoming more health conscious than ever before. They are embracing the use of cosmetics in so many ways to reach new levels of experience and even personalization. This also means consumers are becoming more curious and familiar with what they put on their skin using the big wide web to make sense of the ingredients list.
One of the most popular resources used on the web is the Environmental Working Group's Skin Deep. A site using easy-to-understand scores to assess ingredients' human safety. There are also easy-to-use apps such as Think Dirty.
These resources, even if they might be controversial, offer the clarity and simplicity consumers desire. This makes them choose products according to the presence or lack of particular ingredients or to good scores.
Long-term Preservatives Strategy
The skin is still an unfolding mystery. Learning about ingredient exposure and its impact on the skin continues to evolve. For example, the restriction of parabens allowed manufacturers to replace them with MI and MIT. This led to a sudden and sharp increase in exposure to these substances. This further caused a dermal outbreak and subsequent mistrust in the industry.
The authorities acted quickly and restricted them to rinse-off products only. However, we learnt that the overall ingredients exposure can vary and increase as the market grows. Hence, diversifying the exposure to different preservatives can help keep them around for longer.
Hoping more preservatives to be added in Annex V reducing the exposure of the existing ones is wishful thinking. High cost of red tape is involved in registering new preservatives. This makes it quite unlikely that raw material manufacturers will invest in the registration process of new preservatives.
You can have a strategic approach to choosing a resilient preservative system. This can be done by diversifying the use of preservatives and combining them with multifunctionals. This approach will help you to reduce the risk of antimicrobial resistance.
How to Start with Natural Cosmetic Preservation?
How to Start with Natural Cosmetic Preservation?
The free-from trend has been gaining momentum among consumers over the last two decades. Ingredient manufacturers have been launching new naturally derived multifunctionals to meet this trend. They also help formulators obtain a legally compliant formula that is protected over time.
The first step is to find potential multifunctional ingredients that would be ideal for the application in question. For example, a shampoo, a face cream, or an eye cream could take different multifunctionals such as:
- Foam boosters,
- Emulsion stabilizers, or
- Antioxidants
They may be only antibacterial or only antifungal or might boost preservative performance. To ease the selection part of the process you can find many multifunctionals in The Green Chemist Handbook on Cosmetic Preservation and then use the SpecialChem platform to find additional information.
Learn about some of the natural preservation options available today.
Essential Oils
Essential oils can possess specific antimicrobial properties based on the presence of particular compounds whose concentration may vary from batch to batch. Some of the common oils used for their antimicrobial properties are:
- Melaleuca alternifolia leaf oil (tea tree),
- Thymus vulgaris leaf oil (thyme),
- Cymbopogon citratus leaf oil (lemongrass),
- Origanum vulgare leaf oil (oregano), and many others.
As essential oils contain allergens, it is important to use them at safe levels for the skin.
So, can we use essential oils in cosmetics to serve this same function? Is it legal if we do so?
The answer is they are legal to use but it is best to use them in support of a comprehensive preservative or antimicrobial system.
Natural Multifunctionals Based on Glycols
Glycols are not found in nature, but thanks to the advances in biotechnology several glycols can now be obtained from biofermentation. These naturally derived ingredients allow formulators to use lower preservative levels or to give a broad spectrum natural protection in suitable applications.
Recommended products for the preservation of natural cosmetics are discussed below.
- A-Leen® 5 (formerly called Pentiol Green +) by Minasolve
- INCI: Pentylene Glycol; Use level: 0.5 >5.0%
- Renewable alternative to petro-sourced Pentylene Glycol
- 100% Derived-natural, Ecocert COSMOS approved
- E-Leen® 8 by Minasolve
- INCI: Caprylyl Glycol (and) Glycerin (and) Aqua
- Derived from sustainably sourced coconut and palm kernel oils
- 100% vegetal, ECOCERT verified and COSMOS & NATRUE approved
- Zemea® Propanediol by Tate and Lyle
- INCI: Propanediol
- Preservative-boosting humectant which can replace petroleum-based glycols such as propylene glycol, butylene glycol and glycerin
- Certified by NPS and considered organic ingredient under the definitions of ISO 16128-1
- Hydrolite® 5 green by Symrise
- INCI: Pentylene Glycol
- A by-product coming from sugar cane
- 100% bio-based carbon, COSMOS approved
Organic Acids and Their Salt Derivatives
In this context, organic acids mean Carbon based acids rather than those derived from organic crops. Weak organic acids are used as preservatives in the food industry. Their antimicrobial performance is pH-dependent. They are usually available from petrochemical and natural sources. But today some of them can be obtained via biofermentation. Some of the organic acids used in cosmetics are:
Propionic acid is an organic acid with a characteristic smell. It is found in Annex V with a permitted maximum level of 2%. It is available from petrochemical or natural sources which are COSMOS approved.
Benzoates are derivatives of benzoic acid and are also found in Annex V. They are tasteless and odorless substances. Maximum permitted concentration of benzoic acid is 0.5% for leave-on and 2.5% for rinse-off. COSMOS-approved grades are available.
Sorbic acid and its salts such as sodium sorbate, potassium sorbate, and calcium sorbate. They are found in Annex V, and it is restricted at 0.6%. COSMOS-approved grades are available.
Dehydroacetic acid and its Sodium salt, Sodium dehydroacetate, are found in Annex V. They are restricted to a maximum concentration of 0.6%. Not permitted in sprays and aerosol applications.
Organic acids are very common in the cosmetic industry. They can be blended with multifunctionals such as caprylyl glycol, honokiol, and glucono delta lactone.
Why Go for Alternative Preservatives to Meet Green Cosmetics Labels?
Sustainability has gone beyond the trend status. It is becoming an expectation for consumers who are becoming more aware of what they put on their skin and shop by avoiding controversial ingredients. Multifunctionals from renewable and responsible sources allow formulators to achieve:
- Products with a higher natural percentage
- More with less by using lower preservative levels to get the same antimicrobial performance.
Switch to natural preservative alternatives to meet green cosmetics labels »
Concluding with a Checklist
Concluding with a Checklist
 ✓ Add preservatives at the end of the formulation process right before cooling to avoid degradation
✓ Use the lowest effective concentration of preservative to minimize the risk of irritation or toxicity
✓ Use a combination of preservatives to provide broad-spectrum protection against microorganisms
✓ Follow GMPs and use ISO standards for proper preservative handling
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FORMULATION STRATEGIES |
 ✓ Avoid using ingredients that are known to interact with preservatives
✓ Avoid incorporating ingredients that may be incompatible with the preservative
✓ Disperse and dissolve preservatives properly to ensure efficacy - use solubilizers if needed
✓ Use chelating agents and antioxidants to improve preservative stability
✓ Avoid using metal processing equipment that may interact with preservatives
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INGREDIENT COMPATIBILITY |
✓ Adjust pH to the optimal range for preservative functionality after addition
✓ Control time and temperature during heating steps to prevent preservative destruction
✓ Test preservative efficacy over shelf life with microbiological challenge tests
✓ Maintain strict hygiene and microbial controls throughout manufacturing
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PROCESSING CONDITIONS |
 ✓ Maintain strict hygiene and microbial controls throughout manufacturing
✓ Retain preservative efficacy during filling, packaging, and consumer use
✓ Ensure finished product has appropriate viscosity to enable preservative diffusion
✓ Package the product in a way that minimizes contamination
✓ Store the product in cool, dry conditions
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PACKAGING
TIPS |
Explore Various Preservatives Available for Cosmetics
View a wide range of preservatives available in the market today, analyze technical data of each product, get technical assistance or request samples.
References:
- pH testing cosmetic products few tips, Lisalise Blog
- List of preservatives allowed in cosmetic products, European Union Official Website
- Parabens in cosmetics, US FDA Official Website
- Parabens used in cosmetics, European Union Official Website
- Cosmetic Preservatives Market, Global Market Insights
- Preservative challenge test, Microchem Laboratory
- Why is Preservative Efficacy Testing important in cosmetics?, Jake Robinson, ADSL
- Natural Preservative Alternatives, Nick Morante
- Preservatives Used in Cosmetics and Personal Care Products, Nick Morante
- The Problem with Parabens, Nick Morante
- More on Natural Preservative, Nick Morante
- Pros and Cons of Alternate Preservative Systems, Nick Morante