CFR > Title 21 - Food and Drugs > CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES > SUBCHAPTER D—DRUGS FOR HUMAN USE (parts 300 to 370) > PART 352—SUNSCREEN DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE [STAYED INDEFINITELY] > SUBPART A—General Provisions (§352.1 to §352.3) > 352.3—Definitions.

352.3—Definitions.

As used in this part:
(a) Minimal erythema dose (MED). The quantity of erythema-effective energy (expressed as Joules per square meter) required to produce the first perceptible, redness reaction with clearly defined borders.
(b) Product category designation (PCD). A labeling designation for sunscreen drug products to aid in selecting the type of product best suited to an individual's complexion (pigmentation) and desired response to ultraviolet (UV) radiation.
(1) Minimal sun protection product. A sunscreen product that provides a sun protection factor (SPF) value of 2 to under 12.
(2) Moderate sun protection product. A sunscreen product that provides an SPF value of 12 to under 30.
(3) High sun protection product. A sunscreen product that provides an SPF value of 30 or above.
(c) Sunscreen active ingredient. An active ingredient listed in § 352.10 that absorbs, reflects, or scatters radiation in the UV range at wavelengths from 290 to 400 nanometers.
(d) Sun protection factor (SPF) value. The UV energy required to produce an MED on protected skin divided by the UV energy required to produce an MED on unprotected skin, which may also be defined by the following ratio: SPF value =MED (protected skin (PS))/MED (unprotected skin (US)), where MED (PS) is the minimal erythema dose for protected skin after application of 2 milligrams per square centimeter of the final formulation of the sunscreen product, and MED (US) is the minimal erythema dose for unprotected skin, i.e., skin to which no sunscreen product has been applied. In effect, the SPF value is the reciprocal of the effective transmission of the product viewed as a UV radiation filter.