Exposure Assessment in a CPSR: How Much of Your Product People Actually Use (Part A, Sections 5 to 7)

Ask most brand owners what a safety assessor looks at and the answer is the ingredient list. That is only half of the job. The other half is exposure: how much of the product a real person puts on, how often, where, for how long, and how much of each ingredient that adds up to. Sections 5, 6 and 7 of Part A of a Cosmetic Product Safety Report exist to pin that down.

It explains something that puzzles a lot of formulators. Why can an ingredient pass at a given percentage in a shower gel and fail at the same percentage in a body lotion? Why do a face oil, a body oil and a massage oil each get a different answer? Because the ingredient is the same and the exposure is not. This guide walks through how exposure is assessed, using the figures in the SCCS Notes of Guidance, 12th revision, and shows what it means for the way you describe your product.

Why exposure matters as much as the ingredient

Toxicology tells the assessor how much of a substance is harmful. Exposure tells them how much of it your customer will actually receive. A safety conclusion needs both, and the margin of safety is simply the first number divided by the second. If the exposure side of the sum is wrong, the margin of safety is wrong, however good the toxicology data are.

The same law applies on both sides of the Channel. Annex I of Regulation (EC) No 1223/2009 sets out what Part A of the report must contain, and the GB version carries the same Annex I wording, enforced through the Cosmetic Products Enforcement Regulations 2013. Sections 5 to 7 read the same in both markets, and assessors on both sides generally draw their daily use figures from the SCCS Notes of Guidance, 12th revision published by the EU's Scientific Committee on Consumer Safety.

Section 5: normal and reasonably foreseeable use

Annex I asks for "the normal and reasonably foreseeable use of the product", and says the reasoning must be justified in light of the warnings and other explanations on the label. Normal use is what you intend: a body lotion smoothed over the body after a shower. Reasonably foreseeable use is what people predictably do anyway. They put the body lotion on their face when the weather is bad. They use it twice a day in winter. A parent uses it on a child.

Foreseeable use stops short of deliberate misuse. Nobody assesses a body lotion for eating it. But it does cover predictable accidents, such as a lip balm being swallowed in small amounts or a bath product getting into the eyes. The SCCS guidance lists what the assessor needs to know: the product type, the site of application, the frequency, the total area of skin contact, the duration, the group of people it is aimed at, and for some products whether it is used on skin exposed to the sun, indoors or outdoors.

Why the assessor asks so many questions. Everything in sections 6 and 7 is built on section 5. Describe a product as a hand cream and later market it as an all over moisturiser, and the exposure in the report is several times too low. The report then covers a product you do not actually sell.

Section 6: how much product a person uses

Section 6 puts numbers on the product itself. Annex I lists what it must consider: the site and surface area of application, the amount applied, the duration and frequency of use, the exposure routes, and the people the product is meant for. It also asks for secondary exposure by routes other than direct application, with the examples of unintended inhalation of sprays and unintended swallowing of lip products.

Assessors do not guess the amounts. The SCCS publishes default values taken from a large consumer study carried out by Cosmetics Europe in Spain, Great Britain, France, Germany and Denmark. For each product type the figure is the 90th percentile of daily use, so it is deliberately set towards heavy use. The aim is to protect the heavy user, not the average one. Here are the main figures from Tables 3A and 3B of the guidance.

Product type	Daily amount applied (g/day)	Retention factor	Daily exposure, amount x retention (g/day)	Relative daily exposure (mg/kg bw/day)
Shower gel	18.67	0.01	0.19	2.79
Shampoo	10.46	0.01	0.11	1.51
Hair conditioner	3.92	0.01	0.04	0.67
Body lotion	7.82	1	7.82	123.2
Face cream	1.54	1	1.54	24.14
Hand cream	2.16	1	2.16	32.70
Deodorant, non-spray	1.50	1	1.50	22.08
Liquid foundation	0.51	1	0.51	7.90
Lipstick, lip salve	0.057	1	0.057	0.90
Toothpaste (adult)	2.75	0.05	0.138	2.16
Mouthwash	21.62	0.10	2.16	32.54

Three things are worth knowing about this table. First, the last column is based on the actual body weights of the people in the study, not on a flat 60 kg, which is why 7.82 g of body lotion works out at 123.2 mg/kg bw/day and not 130. If you use the relative column, do not divide by 60 again. Second, hair conditioner is in Table 3B, which carries older figures from the SCCNFP and Colipa, not the large study. Third, the scale of the gaps is the point. A body lotion delivers about five times the product of a face cream. A shower gel is used in large amounts but delivers a small fraction of that, because almost all of it goes down the drain.

Products that are not in the tables are assessed against the closest category or with a justified estimate of the assessor's own. The SCCS says plainly that it does not provide values for every category. Two examples from the guidance are sunscreen, where 18.0 g a day is used, and shaving cream, where the skin area is set at 305 cm². We cover the sunscreen assumptions in our guide to SPF claims, testing and labelling and the shaving figures in our article on CPSR for shaving soap and cream.

Retention factors: what they are and are not

Look at the shower gel row again. The daily amount is 18.67 g, but the exposure that counts is only 0.19 g. The difference is the retention factor, 0.01. It was introduced by the SCCNFP to allow for rinsing off and for dilution when a product is used on wet skin or wet hair. It is a modelling convention, not a laboratory measurement of what stays on the skin. The guidance sets it at 0.01 for shower gel, shampoo and conditioner, at 0.10 for hair styling products and make-up remover, and at 1 for leave on products such as creams, lotions and deodorant.

That is why a shampoo bar containing an ingredient of concern can pass where a leave on serum with the same ingredient at the same percentage would not. It is also why a preservative or fragrance limit can be higher in a wash off product than in a lotion. Our guide to leave on and rinse off products looks at how the category is decided for borderline products such as masks. The short version is that it is the assessor's call, and it has to be justified in the report.

Oral care products need care. For toothpaste (0.05) and mouthwash (0.10) the SCCS uses the factor to work out how much is swallowed, since most is spat out. The swallowed fraction is treated as 100% absorbed unless there is data to the contrary, so oral exposure is calculated separately from skin exposure.

Section 7: from product to ingredient dose

Section 7 moves from the product to each substance in it. The assessor takes the relative daily exposure for the product, multiplies by the concentration of the ingredient and by the fraction that is absorbed. The result is the systemic exposure dose, or SED, in mg per kg of body weight per day. The SCCS writes it as:

If you start from grams per day rather than the relative column, the same sum works by dividing by the default adult body weight of 60 kg. Change any term and the margin of safety changes with it. The assessor controls the absorption value and the body weight, because they come from data or from the guidance. You control the product category, the claims and the concentration.

Dermal absorption. Where a good in vitro or in vivo study exists, the assessor uses the measured value. Where it does not, the SCCS default is 50%, and the same default applies when the data are too poor to rely on. This is a large reason why a well documented ingredient can be allowed at a higher level than a poorly documented one. If a study shows that only 2% crosses the skin, the dose is one twenty-fifth of what the default gives.

A worked example

Take a hypothetical ingredient at 0.5% with no absorption data, so the 50% default applies, and a NOAEL of 50 mg/kg bw/day from a repeated dose study. The same percentage gives very different results depending on where it goes.

Same ingredient at 0.5%	Relative daily exposure (mg/kg bw/day)	Systemic exposure dose (mg/kg bw/day)	Margin of safety if the NOAEL is 50 mg/kg bw/day
In a body lotion	123.2	0.308	162
In a hand cream	32.70	0.082	612
In a face cream	24.14	0.060	829
In a shower gel	2.79	0.007	7,168
In a shampoo	1.51	0.004	13,245

Look at the first row. The body lotion gives a margin of safety of 162, which clears the usual threshold of 100. Push the same ingredient to 1% in that lotion and the dose doubles to 0.616, the margin falls to 81, and the formula fails. In a shower gel you could use many times that level. This is exactly why a limit that is fine in one product is capped in another, and why "it is already in my other product" is not an argument an assessor can accept.

Local effects. Not every endpoint is about a systemic dose. For skin irritation, the question is the amount on a given area of skin, not the dose per kilo of body weight, and the SCCS evaluates it case by case. This is why the assessor needs the surface area of application as well as the daily amount.

Sprays, lip products and oral care

Skin is the main route, but it is not the only one, and the report has to say which routes apply. Sprays can be inhaled. The SCCS figure for a non-spray deodorant is 1.50 g a day, but for a deodorant spray it is 6.54 g, because that figure was measured as the product leaving the can and so includes both what lands on the skin and what is breathed in. For dermal exposure from sprays the guidance suggests worst case fractions of 23.5% for ethanol based sprays and 11.4% for non-ethanol sprays. Inhalation is assessed separately, using the droplet size and a model of the room.

Lip products are the Annex I example of unintended ingestion, so the assessor considers the oral route as well as the skin. Toothpaste and mouthwash are assessed for swallowing, with 100% oral absorption assumed where there is no data. We look at an everyday example in CPSR for lip balm.

Children and other groups of users

The default consumer is an adult of 60 kg, and it does not describe everyone. For children the SCCS points out that the ratio of skin surface area to body weight is higher: roughly 2.3 times the adult ratio at birth, 1.8 at six months, 1.5 at five years and 1.3 at ten. The same amount of cream on a baby therefore means more product per kilo. The SCCS considers that the standard margin of safety of 100 covers this variation for intact skin, but where an ingredient has an endocrine concern or is a CMR the assessor is expected to look at children by age.

Oral care is the clearest example. For children aged 6 and under the SCCS uses a pea sized amount of toothpaste, 0.25 g twice a day, with a retention factor of 40% for ages from seven months to eight years, against 5% for older users, and assumes the swallowed amount is fully absorbed. Mouthwash is generally not for children under six. Annex I also requires a specific assessment in Part B for products intended for children under three and for external intimate hygiene products. Our article on CPSR for baby and children's cosmetics covers what that involves. If your product is aimed at, or foreseeably used by, a particular group, tell the assessor at the start.

Aggregate exposure: the whole routine

People do not use one product a day. A routine might include shower gel, shampoo, conditioner, deodorant, body lotion, face cream, lip balm and toothpaste, and an ingredient found in several of them adds up. The guidance defines aggregate exposure as the sum of the exposures from every product category that contains the ingredient.

For a first tier check, the SCCS gives a table of product exposures that adds up to 17.4 g a day, or 269 mg/kg bw/day in relative terms. For a preservative with the same maximum concentration in every product category, the assessor can multiply that total by the concentration and the absorption fraction. At 0.5% and 50% absorption that gives 0.67 mg/kg bw/day, against 0.31 for the body lotion on its own. Other ingredients are calculated with the category specific concentrations. If the aggregate margin of safety falls below 100, the guidance says industry must decide whether to lower the concentration across the board or take one or more product categories out.

For CMR substances the guidance goes further and expects aggregate exposure from all sources, including non-cosmetic ones. This is part of why an assessor may hold an ingredient below its legal maximum in your product even though your product alone would pass.

What this means for how you position your product

• The category is a safety decision, not just a marketing one. A face oil, a body oil and a massage oil carry different exposures and so different permitted levels.
• Multi use claims raise the exposure. A product sold for face, body and hair is assessed at the highest of the three.
• Leave on or rinse off is decisive. A wash off mask and a leave on mask with the same formula are two different assessments.
• Say who it is for. Children, pregnancy and sensitive skin all change the assumptions, so mention them at the outset.
• Frequency claims count. "Reapply as often as needed" is an exposure statement and the assessor will treat it as one.
• Describe use honestly. The report covers the product as described. If the description is wrong, the report does not cover what you sell.

Where exposure appears in your report

In Part A you will find sections 5 to 7 setting out the use description, the daily amount and retention factor applied, and a table of ingredients with their concentrations and systemic exposure doses. Section 8 then sets each dose against the ingredient's NOAEL to calculate the margin of safety, and Part B explains the conclusion. If you ever want to raise an ingredient level, add a new use claim or move a formula into a new product type, these are the sections that decide whether you can do it without reformulating. A conversation before the packaging is printed costs far less than a reassessment after. Our CPSR example shows where each element sits in a finished report, and Part A explained covers the rest of the sections.

Related reading

• The margin of safety in cosmetic toxicology, explained
• CPSR Part A explained
• CPSR Part B explained
• CPSR example: what a finished report looks like
• Leave on vs rinse off products in a CPSR
• CPSR for baby and children's cosmetics
• SPF claims, testing and labelling rules
• PIF vs CPSR: what goes where
• All regulatory compliance articles

Myths we hear

• Daily use amounts are guesses. They come from a large consumer study in five European countries and are published by the SCCS, set at the 90th percentile so that heavy users are covered.
• A rinse off product barely needs assessing for exposure. It still needs a full assessment. The retention factor lowers the dose, but the skin contact, eye contact and any swallowing still have to be considered.
• If an ingredient is allowed in one of my products it is fine in all of them. Each product category has its own exposure, and the whole routine adds up. A level that passes in a shower gel can fail in a body lotion.
• I can describe the product one way and market it another. The report covers the product as described. A hand cream sold as a body moisturiser has several times the exposure the report assumed.
• Exposure figures are the same in every edition of the guidance. They are revised. The SCCS Notes of Guidance 12th revision is current and a 13th is in preparation, so the assessor uses whichever edition applies on the day.

What to do this week

1. Write down exactly how the product is used: where on the body, how much, how often, leave on or rinsed off, and who it is for.
2. Check your pack copy and website claims against that description. Remove or add claims so they match, because multi use and frequency claims raise the exposure.
3. Tell your assessor in writing about any children, pregnancy or sensitive skin use, and about any spray, lip or oral format.
4. Ask for the exposure table from your CPSR and check that the product category, daily amount and retention factor match your product.
5. Before you raise an ingredient level or add a new use, ask the assessor to rerun the dose calculation first.

Frequently asked questions

Official sources and legislation

• Regulation (EC) No 1223/2009 on cosmetic products (EUR-Lex)
• GB Cosmetics Regulation, Annex I: cosmetic product safety report (legislation.gov.uk)
• Cosmetic Products Enforcement Regulations 2013 (SI 2013/1478)
• SCCS Notes of Guidance for the testing of cosmetic ingredients and their safety evaluation, 12th revision (SCCS/1647/22)
• SCCS Notes of Guidance, 12th revision, full text (PDF)
• SCCS Working Group on Methodologies, minutes of 27 February 2026 (13th revision of the Notes of Guidance in preparation)
• OPSS: making cosmetic products available to consumers in Great Britain