Ozone hole, increased cancer risk ... keywords that concern us all. Therefore, correct sun protection factors (SPF) of sunscreens and cosmetics become increasingly important. Standards for the correct determination of SPF values have been established in the COLIPA-standards. It is based on in-vivo measurements on human skin.

The given task

For research and development of sunscreens and cosmetic products, a system for determining SPF values according to the COLIPA standards had to be developed. It should be able to provide six spots with different intensities of sunlight on the volunteer’s skin simultaneously and of course exclude harmful and unwanted wavelengths. Additionally high homogeneity, reproducibility and long-term stability are necessary.

The solution

Albuquerque (New Mexico) 35°N, blue sky: Standard sun conditions as described in the COLIPA standards. The solar simulator SU6p reproduces these light conditions precisely. The light of a xenon short-arc lamp is specially filtered to achieve the defined spectrum according the COLIPA standard. This light is delivered through six ports directly onto the skin. A special optical system provides these six parallel output spots. By using individually-timed shutters, different doses can be applied to the different spots to create a "light staircase" on the skin. The SPF value is determined by comparing a protected spot (i.e. sunscreen) and a blank spot (unprotected skin). Exposure by a pivoted beam can either be done while the volunteer is sitting or lying down.

for shutter control and measurement evaluation. It calculates the different exposure times for different SPF values and organizes the volunteer database. It calculates the SPF values and reports the results.

 Characteristics

• Efficacy testing of sunscreens and cosmetics
• Precise reproduction of the COLIPA spectrum
• Six spots with individually controllable shutters
• Optimized homogeneity to provide accurate results
• Integrated volunteers protection

The SU6p comes with a software package.