Sun Protection

Institute Dr. Schrader

Sun Protection

Perfect Conditions and In-House Quality Control for Reliable Protection of Consumers

Standard Tests


Determination of Sun Protection Factor (SPF)

  • International SPF Test Method 2006 (COLIPA – CTFA SA – JCIA – CTFA US)
  • International Standard ISO 24444:2019
  • FDA, Final Rule 2011
  • AS/NZS 2604:2021

Determination of Water Resistance or Very Water Resistance

  • Spa Pool Method (ISO 18861:2020/ISO 16217:2020; FDA Final Rule 2011; AS/NZS 2604:2021)
  • Shower Method
Determination of Sweat Resistance by Use of Sauna
In vivo Determination of UVA Protection
  • PPD/PFA according to JCIA Standard 1995 (1999)
  • International Standard ISO 24442:2011(E)
In vitro Determination of UVA Protection
  • COLIPA 2011 (COLIPA Ratio)
  • Boots Star Rating System (2011 Revision)
  • AS/NZS 2604:2021
  • International Standard ISO 24443:2012(E)
  • FDA, Final Rule 2011

Numerous annually certified irradiation systems (Multiport 300W) operating in parallel are available for the in vivo measurements. A special control system in the sun protection laboratory provides perfect, draft-free and constant conditions. In addition to external certifications, the in-house quality control ensures optimal and method-conforming maintenance of all technical specifications.

The same is true for the in vitro measurements of UVA parameters where a Bentham Spectrometer SSUV300 and an Atlas Sun Test CPS+ is used. Cooling during measurement and storage of samples in a climate cabinet is a given, as is a spectrometer that achieves a linear functionality up to an OD 6 and a dynamic range that would definitely be hard to find anywhere else in the world in the area of UVA testing.

Basic Information

The first modern sun cream based on UV filters – “delial Salbe” – was put on the market in 1933. The Hamburg radiation physicist Rudolf Schulze (1906–1974) introduced the term sun protection factor (SPF) in 1956, but at first it was used only by dermatologists. It took some years before it appeared in claims for sun protection products. The sun protection factor (SPF) is supposed to allow the consum-er to directly compare the protection afforded by sunscreens.

Since 2006 a directive of the COMMISSION OF THE EUROPEAN COMMUNITIES governs product claims in Europe. According to this, sun protection products are divided into four protection classes. The measured sun protection factor is rounded down to the next specified discrete protection factor:

Label SPF Protection class
6 Low
15 Moderate
30 High
50+ Very high

Products with sun protection factors below 6 are no longer classified as sunscreens because the main purpose of the product (sun protection) is not achieved due to the low protective effect. Claiming “sun-block” used earlier is likewise no longer used in order to prevent misunderstanding by consumers.

According to the EU directive, sunscreens must provide, in addition to UVB protection, also protection against UVA radiation. The UVA protection factor (UVA-PF) should equal at least 1/3 the sun protection factor.


  • Rohr M, Schrader A, Bielfeld S, Schrader K (1993) Einfluss des Bestrahlungsspektrums bei der Bestimmung des Sonnenschutzfaktors (SSF). Euro Cosmetics 1(1), 53-6
  • Schrader K. (1994) Bewertung von Sonnenschutzmitteln. Skin Care Forum 10, 1-8
  • Schrader K. and Schrader A. (1994) Die Sonnenschutzfaktorbestimmung: Prüfung der Wasserresistenz. Eine kritische Betrachtung aus experimenteller Sicht. Aktuelle Dermatologie 20(4), 130-4.
  • Rohr M., Schrader A. (2003) Quality of irradiation – An essential criterion of SPF determination. SÖFW J 129(3), 2-10