Bath bombs are a craft-market favourite, but they are also full of ingredients that need careful handling: fragrance, colour, surfactants and sometimes glitter. To sell them legally in the UK or EU you need a Cosmetic Product Safety Report (CPSR). This guide explains what makes bath bombs distinctive to assess and what you need to prepare.
For the fundamentals, start with our pillar guide to what a CPSR is. Below we focus on bath bombs specifically.
Do bath bombs need a CPSR?
Yes. A bath bomb is placed in bath water that contacts the whole body, and it is intended to cleanse, perfume or condition the skin — so it is a cosmetic under UK and EU law. Like every cosmetic, it needs a CPSR signed by a qualified assessor before you can sell it. There is no exemption for handmade or small-scale producers.
This catches a lot of new sellers off guard, because bath bombs feel like a fun craft rather than a regulated cosmetic. But the law looks at what the product does and where it is used, not how it is made or how small your operation is. Selling on Etsy, at a market stall or through your own Shopify store makes no difference — the same requirement applies, and the same is true if you give bombs away as samples or in gift sets to promote your brand.
What makes bath bombs different to assess
Bath bombs combine an acid (usually citric acid) and a base (sodium bicarbonate) that react and fizz when wet. The product is then diluted into a large volume of bath water, which the assessor factors into the exposure calculation — the concentration on the skin is far lower than in the bomb itself. At the same time, bath water contacts sensitive areas and the whole body, and bath products carry a slip-and-irritation dimension, so colour, fragrance and surfactant choices all matter. Children are also frequent users, which shapes the foreseeable-use assessment.
There is a second reason bath bombs deserve care. They are a packed mixture of functional and decorative ingredients — acids, bases, surfactants, colours, fragrance, oils, sometimes glitter or embeds — and each one is part of the safety picture. A bath bomb is not really a “simple” product despite its homemade charm; it is a small chemistry set, and the assessor's job is to confirm that everything in it is safe at the level used, once diluted into the bath, for the people likely to use it.
Fragrance and allergens in bath bombs
Fragrance and essential oils must comply with IFRA limits for the relevant bath category, and listed allergens above the threshold must be declared on the label. Bath bombs are often heavily scented, so this is a common area for problems. Keeping fragrance within assessed limits and declaring allergens correctly is essential — our allergen compliance check helps you get there. If you build a whole range around one base recipe, the fragrance CPSR options may also be relevant.
Colourants and the glitter question
Only colourants approved for cosmetic use may be used, identified by their Colour Index (CI) numbers, and the assessor will check these against the permitted list. Two practical pitfalls come up again and again. First, craft or food colourings are not automatically suitable for cosmetics and can stain skin or the bath. Second, traditional plastic glitter is a microplastic and faces restrictions — many makers have moved to mica or biodegradable glitter alternatives. Because the rules in this area have tightened, it is worth confirming your colour and sparkle choices are still permitted before you assess and launch.
Staining is a genuine safety and quality concern, not just an inconvenience. A bath bomb that turns the bath water a deep colour can also tint skin, grout and the tub, and over-concentrated colour is a frequent source of customer complaints. The assessor will look at colourant levels with this in mind. The practical rule is to use cosmetic-grade colour sparingly, choose lake or approved water-soluble colours suited to bath use, and avoid anything sold purely for craft or food applications.
Surfactants, oils and skin safety
Many bath bombs include a mild surfactant such as SLSA for a bubbly effect, plus oils or butters for a moisturising finish. These all form part of the assessment: surfactants for irritation potential, oils for stability and for any allergen content they carry. Added botanicals — dried flowers, herbs — can also introduce a microbiological consideration, even in an otherwise dry product.
Surfactant choice and dose deserve particular attention. A surfactant that is gentle at a low level can become irritating if a maker pushes it up to chase more bubbles, and bath products contact sensitive skin. The assessor weighs the surfactant against the dilution in the bath and the foreseeable users, including children. Likewise, any oils that make the bomb feel luxurious add richness but also a small slip risk and a stability consideration, both of which the assessment takes into account.
Testing and stability
A dry bath bomb generally has low water activity and so a lower microbiological risk than a water-based product, which often means less testing. The assessor will still want confidence in the product's stability over its shelf life — bath bombs can soften or lose fizz if they absorb moisture — and will consider any oils that could oxidise. To understand why a CPSR is an assessment rather than a single lab test, see our guide on whether a CPSR is a 'test'.
Humidity is the quiet enemy of a bath bomb. Because the fizz depends on the acid and base staying apart until they hit water, a bomb that draws in moisture during storage can react prematurely, going flat and crumbly. Sensible packaging, dry storage and a realistic shelf life all feed into the safety and quality picture, and your assessor will expect your product to hold up under normal conditions of sale and use.
Variants and cost
Most sellers offer many colours and scents on one base formula. One assessment can often cover that family of variants — see our variants guide — which keeps costs down. CPSRs start from around £55 for a single product, with reduced rates for variants assessed together. Compare the single and multiple-variant options to see what fits your range.
Common bath bomb mistakes
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Using food or craft colourings not approved for cosmetics.
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Using plastic glitter now subject to restriction.
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Over-fragrancing beyond IFRA limits.
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Missing allergen declarations for essential oils.
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Assuming a dry product needs no assessment at all.
What to prepare for your bath bomb CPSR
Having your information ready makes assessment faster and cheaper. For bath bombs, prepare:
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Your full formula with exact percentages, including acids, bases, surfactants and oils.
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IFRA certificates and allergen declarations for all fragrance and essential oils.
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CI numbers and cosmetic-grade documentation for every colourant, mica and glitter.
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Supplier sheets for any surfactant (such as SLSA) and any active or botanical added.
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Details of any embeds, toys or decorations included in the bomb.
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Your packaging and label artwork.
Labelling bath bombs
Your label must reflect the assessment. That means an INCI ingredient list in descending order, the fragrance allergens you declared, the net weight, a best-before or period-after-opening, batch identification, your Responsible Person details, and any warnings the assessment requires — for example a caution about slippery surfaces or keeping the product away from children's reach. Decorative bath bombs with embedded toys may need additional warnings. As always, the label cannot be finalised with confidence until Part B is done, because the assessment can change what must appear on the pack.
Children, foreseeable use and bath safety
Bath bombs are popular with children, and that has to be built into the assessment. Foreseeable use includes a child handling, dropping or even tasting the product, and the assessor considers these scenarios rather than just the ideal adult use. Bright colours and sweet scents make this especially relevant. Practical consequences include keeping fragrance and colour modest, avoiding embeds that pose a choking risk for products aimed at families, and carrying any warnings the assessment identifies. Thinking about real bathrooms and real users — not just the perfect photo — is exactly what a good safety assessment does.
Launching a bath bomb range? Phoenix Safety Consultants assesses your base and variants together for the UK and EU — fragrance, colour, glitter and all — with qualified sign-off and transparent pricing.
Get Your Bath Bomb CPSR →Frequently asked questions
Do I need a CPSR to sell bath bombs?
Yes. Bath bombs are cosmetics under UK and EU law and require a CPSR signed by a qualified safety assessor before sale, with no exemption for handmade or small-scale producers.
Can I use any glitter in bath bombs?
No. Traditional plastic glitter is a microplastic and faces restrictions. Many makers use mica or biodegradable glitter, and any colourant must be approved for cosmetic use with a valid CI number.
Do I need allergen declarations for bath bomb fragrance?
Yes. Listed fragrance allergens present above the threshold — including those in essential oils — must be declared on the label, and fragrance must stay within IFRA limits.
Can one CPSR cover all my bath bomb colours and scents?
Usually yes, when they share the same base formula. A significant change to the base may require a separate assessment.
How much does a bath bomb CPSR cost?
Typically from around £55 for a single product, with reduced rates when assessing several variants on one base together.
References: Regulation (EC) No 1223/2009 (EUR-Lex); UK Cosmetic Products Enforcement Regulations 2013; EU microplastics restriction; IFRA Standards. General information only, not product-specific advice.
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