What Is SPF?
SPF determination measures the sunscreen product's ability to delay UVB-induced erythema (redness). The reference method is the in vivo measurement on volunteers per ISO 24444. UVA protection is determined in vitro per ISO 24443 or in vivo per ISO 24442. For a water-resistance claim, measurement is repeated before and after water immersion per ISO 16217.
Purpose of SPF
The purpose is to show the protection factor declared on the packaging is supported by measurement. In the EU, Commission Recommendation 2006/647/EC defines a framework for sunscreen claims and requires UVA protection to be proportional to SPF.
Which Products Is SPF Applied To?
- Sunscreen creams, lotions and sprays
- Daily care products containing SPF
- Make-up products containing SPF
- Lip protectants
- After-sun and children's sun products
In Which Sectors Is SPF Used?
Standards Related to SPF
- TS EN ISO 24444 (in vivo determination of SPF)
- TS EN ISO 24443 (in vitro determination of UVA protection)
- TS EN ISO 24442 (in vivo determination of UVA protection)
- TS EN ISO 16217 (water resistance — immersion procedure)
- TS EN ISO 18861 (water resistance — retention percentage)
- ISO 23675 (in vitro determination of SPF)
SPF Conditions
- Application amount
- Product quantity per unit area defined in the standard; the result is highly sensitive to this
- Number of volunteers
- The minimum number and statistical criteria defined in the standard for in vivo methods
- Light source
- Solar simulator with the spectral distribution defined in the standard
- Water resistance
- If required, measurement is repeated after the ISO 16217 immersion procedure
Equipment for SPF
- Solar simulator and spectroradiometer
- In vitro UV transmission measurement system and PMMA plates
- Controlled water bath
- Application and weighing equipment
Sample Requirements for SPF
- Market formulation
- Sufficient specimen quantity, determined by the number of volunteers
- Formulation and UV filter information must be provided
- The targeted SPF and water-resistance claim must be provided
Duration of SPF
In vivo studies take weeks due to volunteer enrolment, application and reading steps. In vitro UVA measurement is shorter. If a water-resistance claim is required, immersion and re-measurement steps add to the duration.
SPF Procedure
- 1The study protocol and volunteer inclusion criteria are defined.
- 2Volunteers' skin type and minimal erythema dose are determined.
- 3The product is applied at the amount and with the technique defined in the standard.
- 4Controlled doses are applied with the solar simulator.
- 5Erythema is assessed after the defined time.
- 6SPF is calculated; the relevant in vitro or in vivo method is applied for UVA.
SPF Acceptance Criteria
The declared SPF must be supported by the measurement result and the statistical criteria required by the standard. 2006/647/EC also recommends that the UVA protection factor be no less than a set proportion of the SPF, and that only the defined category wording be used on the label.
Evaluation of Results
Application amount is the most critical variable in the result: applying less than the amount defined in the standard markedly lowers SPF. This also holds for consumer use, and the label is expected to inform users about applying a sufficient amount. The test result alone does not establish compliance: (EC) 1223/2009 also requires appointing a responsible person, maintaining a Product Information File, having a qualified person carry out the safety assessment, and notifying the product to the CPNP. Laboratory data feeds into this file.
SPF Report
- Product identification and UV filter system
- Standard and method applied (in vivo/in vitro)
- Number of volunteers and skin types
- Application amount and technique
- SPF result and statistical assessment
- UVA protection factor and water-resistance retention, if any
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- (EC) 1223/2009 Cosmetic Products Regulation
- 2006/647/EC Commission Recommendation (sunscreen products and claims)
- (EU) 655/2013 (common criteria for cosmetic claims)
Kozmetik Testleri — What Does This Testing Field Cover?
The section below describes the field that the SPF test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Cosmetics testing shows that a product stays microbiologically safe throughout its use, delivers the performance it claims and contains no restricted substances. There is NO PRODUCT APPROVAL in this family: no authority approves a cosmetic product; responsibility rests entirely with the manufacturer and with the responsible person established in the EU.
This responsibility model shapes how the field works. Before the product is placed on the market a product information file (PIF) is prepared, a safety assessment (CPSR) is carried out and notification is completed. Inspection comes afterwards and asks for the file; if the file is incomplete the product is withdrawn from the market. Test reports form the evidence base of that file.
On the microbiological side there are two different questions and each is answered by a separate test. The CURRENT microbiological quality of the product is measured by enumeration and testing for specified microorganisms. The EFFECTIVENESS of the preservative system is examined by deliberately inoculating the product with microorganisms (challenge test): can the product resist repeated contamination throughout its use? A jar of cream is touched by a finger at every use; the preservative system must cope with that.
On the performance side, claim substantiation studies are carried out. For sunscreens, determination of SPF and UVA protection and measurement of water resistance are mandatory and are the basis of the value declared on the label. Evidence is also produced by in vivo or in vitro methods for claims such as moisturisation, appearance of wrinkles, hair care and colour retention.
On the chemical side, banned and restricted substances are screened: heavy metals, prohibited colorants, preservative concentrations, UV filter levels and contaminants such as nitrosamines. Products containing nanomaterials carry a separate notification obligation.
The BAN ON ANIMAL TESTING is the most defining constraint of the field. Animal testing cannot be carried out on finished products or ingredients, and a product tested on animals cannot be placed on the market. Alternative in vitro methods (reconstructed human skin models, cell culture based tests) are therefore at the centre of the field, and toxicological assessment rests largely on existing data, read-across approaches and in vitro results.
Stability and packaging compatibility studies determine shelf life and the period after opening (PAO). The interaction of the product with its packaging is also assessed: an active substance may migrate into the packaging, and substances that should not be present may pass from the packaging into the product.
On the process side, good manufacturing practice is demonstrated through ISO 22716; this is separate from product testing but a mandatory part of the file.
Method groups in this field
Microbiological quality
Enumeration of aerobic mesophilic bacteria, yeasts and moulds; testing for Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and E. coli.
Preservative efficacy
Resistance of the preservative system to repeated contamination by challenge test (ISO 11930).
Sun protection
In vivo SPF determination, in vitro UVA protection determination, water resistance and critical wavelength measurements.
Chemical analysis
Heavy metals, banned and restricted substances, quantification of preservatives and UV filters, contaminant screening.
Safety assessment
In vitro irritation and sensitisation methods, toxicological risk assessment, exposure calculations.
Stability and compatibility
Real-time and accelerated stability, packaging compatibility, PAO determination, sensory and physicochemical monitoring.
Commonly confused in this field
- There is NO CE marking on cosmetics; conformity is demonstrated through the PIF, the safety assessment and notification.
- The responsible person must be established in the EU; unless the exporter arranges this, the product cannot be placed on the market.
- Microbiological quality and preservative efficacy are different tests; a product that comes out clean may still have a weak preservative system.
- The animal testing ban covers ingredients too; animal test data generated for another market creates a problem of use.
- An SPF claim must be supported by measurement; a formulation change requires a new measurement.
- A change of packaging may require the stability and compatibility studies to be repeated.
Which decisions these results support
- The product information file and the safety assessment
- Verification of the preservative system design
- Substantiation of SPF and efficacy claims
- Determining shelf life and the period after opening
- Compliance with destination market restrictions for export
Related Tests
Frequently Asked Questions About SPF
Does in vitro SPF replace in vivo?
In vivo (ISO 24444) is the reference method and forms the basis of the label claim. In vitro methods (including ISO 23675) are valuable for formulation development and screening; which data supports the claim depends on the target market's expectations.
Can I state SPF 100?
2006/647/EC recommends the SPF categories and maximum claim wording to use on the label; common practice is to show the highest category with a specific phrase. Whether your claim is acceptable in the target market is confirmed from the current regulations and guidance.
What is required for a water-resistant claim?
The immersion procedure is applied per ISO 16217 and the SPF measurement is repeated; the retention percentage calculated per ISO 18861 must support the claim. The number of immersions varies by the wording claimed.