Category: Manufacturing Guide

Microbiological testing for cosmetics helps reduce contamination risk, protect consumer safety and support regulatory compliance before products reach the market. From preservative efficacy testing (PET) to microbial limits testing and pathogen screening, the right testing pathway helps brands identify risks early and confirm that formulations remain safe throughout their intended shelf life.

For cosmetic chemists, quality teams and brand owners, microbiological testing is a critical step in developing products that are both effective and safe to use.

Ensuring Product Safety from Lab to Consumer

Cosmetic products can be exposed to microorganisms during manufacturing, filling, storage and everyday consumer use. Without appropriate preservation and testing, contamination may affect product quality, shelf life and consumer safety.

Microbiological testing provides the data needed to assess contamination risk, validate preservative performance and support a safe pathway from formulation through to commercial release.

Why Microbiological Testing Matters in Cosmetics

Cosmetic products, particularly water-based formulations, can be susceptible to microbial growth if they are not properly preserved, manufactured and tested.

Products such as creams, lotions, cleansers, serums and gels may be exposed to contamination through raw materials, processing equipment, packaging or repeated consumer contact.

Safety Risks and Regulatory Expectations

Microbial contamination can lead to:

• Product spoilage, including odour, discolouration or separation
• Reduced preservative effectiveness
• Skin irritation or infection
• Regulatory non-compliance
• Product recalls or market delays

Regulatory frameworks across Australian, European and United States markets expect brands to demonstrate that cosmetic products are microbiologically safe. While specific requirements vary, there is a shared expectation that:

• Products do not contain harmful levels of microorganisms
• Preservative systems are effective throughout the product’s shelf life
• Manufacturing processes minimise contamination risk

This is where microbiological testing for cosmetics becomes essential, providing the evidence needed to confirm product safety and support compliance.

Preservative Efficacy Testing (PET)

Preservative efficacy testing confirms whether a product’s preservative system can effectively control microbial growth over time.

Also known as challenge testing, PET evaluates how well a formulation resists contamination when exposed to specified microorganisms.

How PET Testing Works

During PET testing, a product is intentionally inoculated with selected microorganisms. The preservative system is then assessed at defined intervals to determine whether it reduces or eliminates microbial presence.

Commonly tested organisms include:

• Staphylococcus aureus
• Pseudomonas aeruginosa
• Escherichia coli
• Candida albicans
• Aspergillus brasiliensis

Testing commonly follows recognised standards and methods such as:

• ISO 11930: Cosmetics — Microbiology — Evaluation of antimicrobial protection
• CTFA methods
• Pharmacopoeial methods, where applicable

Samples are generally assessed at staged intervals, such as Day 0, Day 7, Day 14 and Day 28, to measure microbial reduction over time.

Interpreting PET Results

PET results determine whether the formulation meets the relevant acceptance criteria for antimicrobial protection.

• Pass: The preservative system reduces microbial counts within the required limits.
• Fail: The formulation does not achieve sufficient microbial reduction and may require further development.

If a product does not pass PET testing, formulation adjustments may include:

• Optimising the preservative type or concentration
• Adjusting pH or water activity
• Reviewing ingredient interactions
• Improving packaging to reduce contamination risk

PET testing is especially important for products that are regularly exposed to air, water or direct contact during use, including creams, lotions and cleansers.

Contamination and Microbial Limits Testing

Microbial limits testing assesses the actual microbial content of a finished product and confirms whether it meets acceptable thresholds.

While PET evaluates preservative performance, contamination and microbial limits testing checks whether the product contains unacceptable levels of microorganisms at the time of testing.

What Is Tested?

Microbial limits testing may include:

• Total aerobic microbial count (TAMC): Measures the total level of aerobic bacteria present.
• Total yeast and mould count (TYMC): Measures the total level of yeasts and moulds present.
• Specified pathogen screening: Confirms the absence of microorganisms that may present a safety risk.

Specified pathogen screening may include:

• Staphylococcus aureus
• Pseudomonas aeruginosa
• Escherichia coli
• Candida albicans

Depending on the product type, intended use and target consumer, additional organisms may also be assessed.

Spoilage Organisms

Some microorganisms may not present the same level of consumer safety risk as specified pathogens but can still affect product quality. Spoilage organisms may cause:

• Changes in odour
• Texture breakdown
• Discolouration
• Separation
• Visible contamination

Industry Thresholds

Acceptable microbial limits depend on the product category, intended use and applicable regulatory expectations.

General considerations include:

• Low microbial counts for products used away from the eye area
• Stricter limits for products used around the eyes, on mucous membranes or on sensitive skin
• Absence of specified pathogens

Testing requirements are commonly guided by standards and references such as:

• ISO 17516: Cosmetics — Microbiology — Microbiological limits
• Pharmacopoeial references, including USP and EP methods where applicable

Understanding the relevant thresholds helps quality and regulatory teams determine how to test cosmetics for microbes and confirm whether a product is suitable for release.

Delta’s Microbiological Testing Process

Delta’s microbiological testing services are designed to support product safety, regulatory compliance and efficient product development.

1. Sample assessment
   The product is reviewed based on formulation type, intended use and microbiological risk profile.
2. Method selection
   The appropriate testing pathway is selected, which may include PET, microbial limits testing or targeted pathogen screening.
3. Laboratory testing
   Samples are assessed under controlled conditions using validated microbiological methods.
4. Data analysis and reporting
   Results are clearly reported, including microbial counts, pass or fail outcomes and relevant observations.
5. Technical guidance
   Where required, Delta can provide support around reformulation, preservative optimisation and risk mitigation.

Testing Methods

Depending on the product and project requirements, testing may include:

• Preservative efficacy testing to ISO 11930 or an equivalent method
• Microbial limits testing to ISO 17516
• Targeted pathogen screening
• Additional microbiological assessments based on product risk

Turnaround Times

Typical microbiological testing timelines may include:

Timelines may vary depending on the product type, testing method and scope of work.

Accreditation and Standards

Delta’s microbiological testing aligns with recognised standards and methods, including:

• ISO microbiological testing methods
• CTFA guidelines
• Pharmacopoeial standards, where applicable

This supports reliable, reproducible results that can inform quality reviews, product development decisions and regulatory documentation.

Benefits of Microbiological Testing with Delta

Working with an experienced testing partner helps brands identify microbiological risks earlier and make informed development decisions.

Benefits of microbiological testing with Delta include:

• Improved product safety through early identification of contamination risks
• Greater regulatory confidence through testing aligned with recognised standards
• Reduced risk of product recalls, rework or market delays
• More efficient product development through integrated testing and technical support
• Clear, actionable reporting for quality and regulatory teams
• Guidance on preservative optimisation and formulation risk mitigation

Supporting Safe, Market-Ready Cosmetic Products

Microbiological testing is an essential part of developing cosmetic products that remain safe, stable and suitable for consumer use. By assessing preservative performance, microbial limits and specified pathogens, brands can identify potential issues before products reach the market.

Delta supports cosmetic and personal care brands with microbiological testing services designed to strengthen product safety, support compliance and reduce avoidable development risk.

For sunscreen brands, formulators and regulatory teams, understanding these differences is essential for avoiding delays, failed compliance checks or costly reformulations.

This guide provides a practical overview of sunscreen regulations in Australia, the United States and the European Union, helping brands understand key compliance requirements and prepare products for international markets.

Why Sunscreen Regulations Differ Globally

Sunscreens are regulated under different frameworks depending on the country or region.

Some markets classify sunscreens as:

• Therapeutic goods
• Over-the-counter drugs
• Cosmetic products

These classifications influence:

• Approved UV filters
• SPF testing requirements
• Broad-spectrum standards
• Product claims
• Packaging and labelling rules

As a result, a sunscreen that is compliant in one market may require additional testing, documentation or reformulation to be sold elsewhere.

Understanding SPF regulatory requirements early in development can help brands streamline launches and reduce compliance risks.

Sunscreen Regulations in Australia

Australia has some of the strictest sunscreen regulations globally due to the country’s high UV exposure and skin cancer rates. Sunscreens are regulated by the Therapeutic Goods Administration, commonly known as the TGA.

TGA Classification of Sunscreens

Australian sunscreens are generally classified as either primary sunscreens or secondary sunscreens.

Primary sunscreens are regulated as therapeutic goods and must comply with TGA requirements. Secondary sunscreens may be exempt from some therapeutic regulations depending on SPF level, product type and intended use, but claims still need to be appropriately supported.

Required Testing and Labelling

Australian sunscreen products must comply with recognised standards and may require:

• SPF testing
• Broad-spectrum UVA protection testing
• Water resistance testing, if claimed
• Stability and microbiological assessments
• Compliant labelling and claim substantiation

Products are commonly assessed according to Australian and New Zealand sunscreen standards, as well as internationally recognised ISO methods where applicable.

Key Labelling Requirements

Australian sunscreen labels generally include:

• SPF value
• Broad-spectrum claim, where supported by testing
• Water resistance duration, where claimed
• Directions for use
• Active ingredients

Australia commonly uses SPF 50+ as the highest labelled SPF category, even where test results exceed that value.

Because the Australian framework is highly regulated, brands entering the market often require careful testing, documentation and compliance planning.

Sunscreen Regulations in the United States

In the United States, sunscreens are regulated by the Food and Drug Administration, known as the FDA, as over-the-counter drug products.

This makes the US one of the most structured sunscreen markets globally.

FDA OTC Sunscreen Framework

The FDA sunscreen framework outlines requirements relating to:

• Approved UV filters
• Permitted active ingredient concentrations
• Testing methods
• Label requirements
• Acceptable marketing claims

Compared with some other regions, the US has a more limited list of permitted sunscreen actives, which can create formulation challenges for global brands.

Broad-Spectrum and SPF Requirements

To market sunscreen products in the US, brands must perform testing aligned with FDA requirements.

This typically includes:

• SPF testing
• Broad-spectrum UVA testing
• Water resistance testing, if claimed

Broad-Spectrum Claims

Products must pass FDA broad-spectrum testing to claim protection against both UVA and UVB radiation.

If a product does not pass broad-spectrum testing:

• It may still display an SPF value
• It cannot claim broad-spectrum protection
• It may face additional claim limitations

Water Resistance Claims

The FDA does not allow sunscreen claims such as:

• Waterproof
• Sweatproof
• Sunblock

Instead, products may only claim validated water resistance durations such as:

• Water resistant, 40 minutes
• Water resistant, 80 minutes

Drug Facts Panel

US sunscreen labels must also include a standardised Drug Facts panel outlining key product information such as:

• Active ingredients
• Warnings
• Directions
• Usage information

This differs significantly from EU cosmetic labelling requirements and is one of the most important packaging considerations for brands entering the US sunscreen market.

Sunscreen Regulations in the European Union

In the European Union, sunscreens are regulated as cosmetic products under the EU Cosmetics Regulation framework. Unlike Australia and the US, sunscreens are not classified as therapeutic goods or drug products.

Cosmetics Regulation Framework

EU sunscreen products must comply with requirements relating to:

• EU Cosmetics Regulation requirements
• European Commission sunscreen recommendations
• Product safety assessment
• Ingredient safety rules
• Responsible claims and substantiation

Manufacturers are responsible for ensuring products are safe, effective and supported by appropriate testing and documentation.

The EU framework focuses strongly on:

• Consumer safety
• Responsible marketing claims
• Scientific substantiation
• Product information and safety documentation

UVA Protection Factor Requirements

The EU expects sunscreens to provide balanced UVA protection alongside SPF performance.

To support UVA protection claims, the UVA protection factor should be at least one-third of the labelled SPF value.

Products meeting these expectations may display the recognised UVA logo on packaging, where relevant requirements are met.

EU sunscreen testing commonly uses:

• ISO 24444 for SPF testing
• ISO 24443 for UVA testing

The EU also restricts misleading or exaggerated sunscreen claims, helping ensure consumers receive clear and accurate information about product protection.

Key Differences Between Australia, the EU and US

Although sunscreen regulations share similar goals, each region applies different compliance pathways.

Regulatory Classification Comparison

These classifications affect registration requirements, documentation, permitted ingredients and the types of claims brands can make.

Testing Standards

While ISO standards are widely recognised internationally, the FDA maintains some market-specific requirements that brands need to consider early in development.

Labelling Rules

Because labelling rules differ, many global sunscreen brands require region-specific packaging, claims and compliance documentation.

Preparing Your Sunscreen for Global Compliance

Developing sunscreen products for multiple international markets requires early regulatory planning.

Review Ingredient and Claim Requirements Early

Brands should confirm:

• Approved UV filters in target markets
• Maximum ingredient concentrations
• Broad-spectrum requirements
• SPF claim expectations
• Water resistance claim requirements

This helps reduce the risk of reformulation later in development.

Validate Product Performance

Global sunscreen products commonly require:

• SPF testing
• UVA testing
• Stability testing
• Water resistance validation
• Microbiological testing where relevant

Early-stage in vitro testing can help identify formulation weaknesses before final validation testing begins.

Work With Experienced Testing Partners

Global sunscreen compliance involves more than achieving a target SPF number.

Brands also need support with:

• Regulatory expectations
• Test selection
• Claim substantiation
• Documentation requirements
• Market-specific interpretation

Working with experienced laboratories helps streamline compliance and reduce delays during launch preparation.

FAQ: Sunscreen Regulations

Are sunscreens regulated differently in each country?

Yes. Sunscreens may be classified as therapeutic goods, over-the-counter drugs or cosmetic products depending on the region.

What are the TGA sunscreen requirements?

The TGA requires recognised SPF and broad-spectrum testing, compliant labelling and adherence to Australian sunscreen standards for regulated therapeutic sunscreen products.

What are FDA sunscreen regulations?

The FDA regulates sunscreens as over-the-counter drugs and requires approved active ingredients, SPF testing, broad-spectrum validation where claimed and Drug Facts labelling.

What are EU sunscreen regulations?

The EU regulates sunscreens as cosmetic products and requires product safety substantiation, SPF validation, UVA protection standards and responsible claims.

Why is international sunscreen compliance challenging?

Different testing standards, ingredient approvals, product classifications and labelling rules across regions make global sunscreen compliance complex.

Support Global Sunscreen Compliance With Delta

Navigating international sunscreen regulations requires strong testing, clear documentation and an understanding of market-specific compliance expectations.

Delta supports sunscreen brands with SPF testing, UVA validation and regulatory-aware testing programs aligned with Australian, US and EU requirements.

Launching sunscreen products internationally? Delta can help ensure your products meet global testing and regulatory standards.

• Gradual ingredient degradation
• Changes in pH or viscosity
• Microbial growth
• Packaging interactions

Based on the results, manufacturers may take actions such as:

• Adjusting the formulation
• Modifying preservatives
• Selecting more suitable packaging
• Updating shelf-life claims

Clear and structured reporting helps R&D teams and regulatory professionals make informed decisions quickly.

Why Choose Delta

Choosing an experienced manufacturing partner is important when planning and managing stability testing. Delta supports cosmetic, personal care and pharmaceutical manufacturers through:

• Stability testing protocols developed around the product and its requirements
• Accelerated and long-term stability studies
• Clear reporting of stability results
• Support throughout the testing process and wider product development journey

With practical experience across product development and manufacturing, Delta helps brands understand how their products perform over time and make informed decisions before market launch.

Need support with product stability testing?

Delta works with cosmetic, personal care and pharmaceutical brands to design practical stability testing programs that support product quality, regulatory confidence and successful market launches.

Speak with Delta’s team to discuss a stability testing protocol tailored to your product, packaging and launch timeline.

Contact Delta