What Is a CPSR? CPSR Part B Explained: The Assessment and Sign-Off

If Part A of the CPSR gathers the evidence, Part B is where an expert makes sense of it. Part B the cosmetic product safety assessment is the reasoned conclusion on whether a product is safe, the warnings it must carry, and the qualified sign-off that gives the report legal weight. This guide explains how it works.

For context, see our pillar on what a CPSR is and the companion guide to Part A. Here we focus on the assessment itself.

What Part B is

Part B is the professional judgement at the heart of the CPSR. Where Part A compiles data, Part B interprets it: the safety assessor takes the composition of the product, exposure, toxicological and testing information and reaches a documented conclusion about the product's safety. It is the part that requires a qualified professional and their signature.

The UK Cosmetics Regulation specifies what Part B must contain: the assessment conclusion, the labelled warnings and instructions for use, the reasoning leading to the conclusion, and the assessor's credentials and approval. Each of these elements has a distinct purpose, which we examine below.

The assessment conclusion

The core of Part B is the conclusion a clear statement of whether the product is safe for human health when used under normal and reasonably foreseeable conditions. This is the bottom line the whole report builds towards. A product is either assessed as safe for human health (possibly subject to specified conditions and warnings) or it is not, in which case it cannot be placed on the market as formulated.

This conclusion is not a formality. It represents the assessor's expert determination, based on the evidence, that the product will not harm users in the ways the assessment has considered. It is the statement an authority will look to first, and it is what allows the Responsible Person to place the product on the market with confidence, backed by a complete product safety report.

Required warnings and instructions for use

Part B specifies any warnings and instructions for use that must appear on the product label for it to be safe. These might include directions to avoid contact with the eyes, cautions for sensitive skin, instructions to keep out of reach of children, or specific warnings tied to particular ingredients — for example sun-sensitivity warnings for products containing certain acids.

These are not optional label decorations: they are safety-critical requirements determined by the assessment. A product may only be safe because it carries a particular warning, so the label must reflect exactly what Part B specifies. This is a key link between the CPSR and compliant labelling.

The reasoning behind the conclusion

Part B must set out the reasoning the logic and evidence that led to the conclusion. This is where the assessor explains how they weighed the exposure to the cosmetic against the toxicological data for each substance, how they considered the product as a whole, and why they concluded as they did. It is what makes the assessment transparent and defensible.

A central technique in this reasoning is the Margin of Safety calculation for substances of concern comparing the level at which a substance shows no adverse effect against the actual exposure from the product, to confirm an adequate safety margin. The depth and rigour of this reasoning is what distinguishes a sound CPSR from a superficial one.

The assessor's credentials and sign-off

Finally, Part B records the name and qualification of the assessor and their signed approval. This is what makes the CPSR valid: the assessment must be carried out and signed by a professional qualified in pharmacy, toxicology, medicine or a comparable discipline. An assessment without a qualified sign-off is not a valid CPSR, however thorough the analysis.

The assessor's qualification is a legal precondition and is verified if the report is ever scrutinised. This is why the choice of assessor matters, and why brands rely on properly qualified professionals our safety assessors meet this standard for every report we produce.

How the assessor reaches a decision

In practice, the assessor works through the product systematically. They check each ingredient against the regulatory Annex I to confirm none is prohibited and that restricted substances, preservatives, colourants and UV filters are within their permitted limits and conditions, covering the full qualitative and quantitative composition. They review the stability and microbiological quality data, and the physical and chemical properties the physical and chemical characteristics of both raw materials and finished product. They then assess exposure substance by substance against safe levels.

They also consider the product holistically interactions, the cumulative picture, the foreseeable users, the intended use, and the packaging material. Where something falls short, they may require reformulation, additional data or specific warnings before they can conclude the product is safe. Only when the whole picture supports it do they sign off.

When Part B cannot conclude a product is safe

Sometimes the assessment cannot conclude that a product is safe as presented. Common reasons include an ingredient exceeding its permitted level, a substance lacking adequate safety data, inadequate preservation, or an exposure that produces too small a margin of safety. In these cases the assessor cannot simply sign off the issue must be resolved first.

This is a feature, not a failure, of the system. A CPSR that surfaces a genuine safety problem before launch has done its job, sparing the brand a far worse outcome later. Resolving the issue usually by reformulating, gathering more data, or adjusting the use or warnings allows the assessment to proceed to a positive conclusion.

Keeping Part B current

Because Part B is a judgement about a specific product in the light of current knowledge and regulation, it must be kept up to date. If the formula changes, if new safety data emerges about an ingredient, or if a regulatory change restricts a substance, the assessment may need revisiting. The Responsible Person is expected to ensure the CPSR remains valid and the Product Information File stays current.

Regulatory changes are the most common trigger, given the steady stream of ingredient restrictions in both the UK and EU. A product that was safely assessed under one set of rules may need reassessment and sometimes reformulation when those rules change reflecting the normal and reasonably foreseeable use standard the assessor originally applied, now re-tested against the normal and reasonably foreseeable conditions that follow a rule change. Treating Part B as a living conclusion, not a permanent one, is part of good compliance.

Why the assessor's judgement matters

Part B is fundamentally an exercise in expert judgement, and that is precisely its value. Two products with similar-looking formulas can warrant different conclusions depending on their use, exposure, and the specific data behind each ingredient, including any challenge test or toxicological profile findings. A qualified assessor brings the training to weigh these factors correctly to know when a margin of safety is adequate, when a warning is required, and when a product simply cannot be signed off as it stands.

This is why the assessor's qualification is a legal requirement rather than a preference. The regulation entrusts a significant judgement to the assessor, and it insists that judgement come from someone properly trained to make it. It is also why a CPSR should never be treated as a document to be produced as cheaply and quickly as possible: the quality of the judgement in Part B is the quality of the safety assurance itself.

For brands, the takeaway is to value the assessment for what it is a professional safeguard and to engage assessors who will do it rigorously. A thorough Part B protects customers and the business alike, and stands up when it matters most: under the scrutiny of a market surveillance authority or in the aftermath of a complaint.

Part B at a glance

Frequently asked questions

References: Regulation (EC) No 1223/2009, Annex I Part B and Article 10(2) (EUR-Lex); UK Cosmetics Regulation as retained; SCCS Notes of Guidance. General information only, not legal advice.