The photoallergy test is an in vivo evaluation designed to assess a product’s potential to induce delayed, immune-mediated skin reactions following exposure to light.

Unlike phototoxicity, which evaluates immediate irritation responses, this test focuses on photoallergic reactions that develop over time after repeated exposure, providing a deeper understanding of long-term skin compatibility under UV conditions.

This test provides objective evidence for claims related to skin tolerance in sun-exposed conditions, particularly for products intended for frequent or prolonged use.

Purpose of the Test

The goal of this test is to determine whether a cosmetic product may trigger delayed hypersensitivity reactions when applied to the skin and subsequently exposed to UV light.

It is particularly relevant for leave-on products and formulations intended for repeated use in sun-exposed conditions, where cumulative exposure may influence skin tolerance.

Methodology

The study is performed as an in vivo clinical assessment, combining repeated product application with controlled UV exposure and dermatological evaluation.

• Number of volunteers: 10
• Measurement points: Baseline and follow-up assessments over the study period
• Duration: 14 days
• Test conditions: Repeated application with controlled UV exposure
• Number of samples required: 50 ml of finished product

Test Procedure

1. Volunteer selection:
   Ten participants with healthy skin are selected for repeated exposure testing.
2. Baseline assessment:
   Initial dermatological evaluation is performed prior to product application and UV exposure.
3. Repeated product application:
   The test product is applied according to protocol over the study duration.
4. Controlled UV exposure:
   Treated areas are exposed to UV light under standardized conditions at defined intervals.
5. Follow-up evaluations:
   Skin is monitored throughout the study to detect any delayed or progressive reactions.
6. Data analysis:
   Observations are classified to determine the presence or absence of photoallergic response.

Parameters Evaluated

• Delayed skin reactions under UV exposure — dermatological assessment
• Signs of sensitization — including redness, itching, or localized reactions
• Reaction onset and progression over time
• Classification of skin response
• Overall tolerance under repeated light exposure conditions
• Safety profile in UV exposure context

Sample Requirements

• Quantity: 50 ml of finished product
• Condition: Stable, ready-to-use formulation
• Product types: Leave-on products and formulations intended for repeated use in sun-exposed conditions

Results & Reporting

The laboratory report includes:

• Dermatological evaluation of skin responses over time
• Classification of observed reactions
• Assessment of delayed response patterns
• Summary of product tolerance under repeated UV exposure
• Safety profile in UV exposure context

Why This Test Matters

The Photoallergy Test provides critical insight into delayed skin reactions that cannot be identified through phototoxicity testing alone.

It supports claims such as:

• “Tested for tolerance under repeated UV exposure”
• “Suitable for prolonged use in sun-exposed conditions”
• “Dermatologically evaluated for delayed light-induced reactions”

This test is essential for comprehensive safety assessment, particularly for products intended for continuous or long-term use, helping ensure a high level of consumer safety and confidence.

Phototoxicity vs Photoallergy

Both tests evaluate skin reactions under UV exposure, but they address different risks.

Phototoxicity measures immediate irritation caused by the interaction between a product and UV light, typically appearing within hours after application.

Photoallergy assesses delayed, immune-mediated reactions that develop after repeated exposure, usually appearing days later.

Together, they provide a complete evaluation of both immediate and long-term skin tolerance under UV exposure.

How the Process Works

1. Order your lab test
   Select the appropriate package and complete your purchase on our website.
2. Receive secure access
   After purchase, you’ll receive login details to our secure portal.
3. Complete the intake form
   Provide your product details and upload available documentation.
4. Send us your samples
   We’ll guide you on exactly what to send to our lab. The sample amount and number depends on several factors. The exact number of samples will be communicated via the portal.
5. Lab testing
   We start the lab test.
6. Receive your results
   Our safety assessor will prepare the lab test results and provides this via the portal.