CPSR Meaning: CPSR Part A Explained and Safety Information Requirements

Part A of the CPSR the cosmetic product safety information is the evidence base on which the whole cosmetic safety assessment rests. It is where all the data about a product is gathered and characterised, before the assessor interprets it in Part B. This guide explains what Part A must contain and why each element matters.

For the wider context, see our pillar on what a CPSR is and the companion guide to Part B. Here we focus on the information requirements.

What Part A is for

Part A does not reach conclusions it compiles the facts. Its purpose is to bring together, in one structured place, everything needed to judge whether the product is safe: what is in it, what those substances do, how the product will be used, and how much exposure results. The UK Cosmetics Regulation sets out the categories of information that must be included, and a complete Part A addresses each of them.

The quality of Part A determines the quality of the assessment. If the underlying information is incomplete, inaccurate or missing, the assessor in Part B cannot reach a sound conclusion. This is why gathering robust Part A data much of it from your suppliers is so central to obtaining a good CPSR, and to demonstrating product safety throughout.

1. Quantitative and qualitative composition

The foundation of Part A is the full formula: every ingredient identified by its INCI names, with its exact concentration the qualitative and quantitative picture the assessor works from. This includes the function of each substance and, for fragrances and complex materials, the relevant details of their composition. Without a complete, precise product formula, none of the subsequent assessment is possible.

This is also where the identity and purpose of each ingredient are documented, giving the assessor the raw material to check every substance against the regulatory Annex I and to calculate exposure. Accuracy here is non-negotiable an incorrect percentage can invalidate the entire assessment.

2. Physicochemical characteristics and stability

Part A records the physical and chemical characteristics of the raw materials and the finished product properties such as pH, viscosity and physical form and the product's stability under reasonably foreseeable storage conditions. Stability test data typically supports this element, alongside compatibility test results where relevant, establishing that the product remains safe and functional over its shelf life.

Stability matters for safety, not just quality: a product that separates, changes pH or degrades over time can become unsafe or ineffective, and its preservation can fail. Documenting stability underpins the durability date and gives the assessor confidence the product behaves predictably.

3. Microbiological quality

The microbiological quality of the product must be documented, including specifications and, for products at risk of microbial growth, the results of a preservative efficacy (challenge test). Water-containing products are the main concern here, since they can support the growth of bacteria, yeast and mould if not properly preserved.

This element demonstrates that the product will remain microbiologically safe through its life and normal use, including repeated opening and contact. Anhydrous products carry lower microbiological risk, but the quality still needs addressing. Getting preservation right is one of the most important safety considerations for many product types.

4. Impurities, traces and packaging information

Part A addresses the purity of substances, any traces of prohibited substances that may be unavoidably present, and the relevant characteristics of the packaging material particularly its stability and any potential for substances to migrate from the packaging into the product. Trace contaminants such as heavy metals in natural minerals are a common focus.

This element ensures that what reaches the consumer is understood not just in terms of the intended formula but also of unavoidable impurities and packaging interactions. It is why certificates of analysis and packaging compatibility information form part of a thorough Part A.

5. Normal and reasonably foreseeable use

The assessment must reflect the product's intended use how the product is actually used, not only as intended, but as could reasonably be foreseen. This is the normal and reasonably foreseeable use standard the regulation applies. It includes the site of application, whether it is left on or rinsed off, how much is used, how often, and who is likely to use it, including vulnerable groups such as children. Foreseeable misuse is considered where relevant.

This element is critical because safety is contextual: the same substance can be safe in a rinse-off product and unsafe in a leave-on one, or safe for adults but not for children. Accurately describing real-world use is essential to a meaningful assessment.

6. Exposure to the product and to substances

Building on use, Part A quantifies exposure to the cosmetic both to the finished product and to each individual substance within it. This considers the amount applied, the frequency, the area of skin, the route of exposure (dermal, inhalation, oral for lip and mouth products) and how much exposure to the body results.

Exposure is the hinge of the whole assessment. In Part B, the assessor compares this exposure against the levels at which each substance is considered safe, applying margin of safety calculations. Getting the exposure calculation right which depends on accurate use and composition data is therefore fundamental.

7. Toxicological profile of the substances

Part A includes the toxicological profile of each substance its relevant hazard information, such as potential for irritation, sensitisation, and systemic effects drawn from established data sources. This is the safety science behind each ingredient, and it is what the assessor weighs against the exposure to judge whether a substance is safe at the level used.

This element leans on published toxicological data, SCCS opinions, and supplier information. Substances lacking adequate data are a problem, since the assessor a qualified professional cannot confirm safety without it, one reason novel or poorly characterised ingredients complicate assessments.

8. Undesirable effects and serious undesirable effects

Where a product is already on the market, Part A records data on any undesirable effects and serious undesirable effects reported adverse reactions experienced by users. For a new product this may be minimal, but the framework exists to capture and reflect real-world safety experience over time.

This element links the CPSR to ongoing safety monitoring. Serious undesirable effects carry specific reporting obligations, and any such data feeds back into the product's safety picture, potentially prompting reassessment. It reflects that safety is monitored throughout a product's life, not only at launch.

9. Other relevant information

Finally, Part A allows for any other information relevant to the safety of the product a catch-all ensuring nothing material is omitted. This might include specific studies, particular considerations for a novel product type, or data relevant to a specific ingredient or claim. It gives the assessment the flexibility to capture whatever relevant information a particular product requires.

In practice this element means Part A is not a rigid checklist to be minimally satisfied, but a genuine effort to assemble everything bearing on safety. A thorough assessor will include whatever is needed to support a sound conclusion, ready to slot into the Product Information File.

Part A information at a glance

Frequently asked questions

References: Regulation (EC) No 1223/2009