Borderline products are so-called borderline cases which are difficult to allocate to a specific product group. They must be classified by specialists according to their purpose, composition, effect, visual appearance, area of application or application purpose on a case-to-case basis.
Overlaps between cosmetics and pharmaceuticals, biocides, utility objects, toys, foods or medicinal products may occur. They are often classified wrongly as cosmetic products. Products that get often mixed up with cosmetics are, for example, healing ointments, which are pharmaceuticals. Additionally, substances that are applied under the skin by injection are not considered cosmetics. Mosquito repellents are biocides. Contact lens fluids and cleaning fluids are medicinal products. Beta-carotene tablets to protect the skin from sunlight in the case of sunlight intolerance are food additives.
More details on the issue of differentiating cosmetics from pharmaceuticals:
The Abgrenzungsbeirat (Advisory Board on Classification) handles problems and issues concerning the differentiation between pharmaceuticals and other products. Manufacturers can submit their product for classification (via form). This application is subject to charges.
You can find important criteria for differentiation primarily in the decisions made by the European Court of Justice.
The European Commission has published a manual, developed together with the Member States, addressing various products. This publication is updated on a regular basis: MANUAL ON THE SCOPE OF APPLICATION OF THE COSMETIC REGULATION(EC) No 1223/2009 (Art.2(1)(A)) (1.Version 2013)
Further guidance documents on borderline products can be found under the following link (cosmetic products – pharmaceutical products, cosmetic products – biocides, etc.) http://ec.europa.eu/health/medical-devices/documents/borderline/index_en.htm
The following publication by the European Council provides an overview of the classification of various borderline products in the Member States: Committee of Experts on Cosmetic Products: Comparative Study on Borderline Products and Borderline Situations. Council of Europe Publishing, 2001. (ISBN 978-92-871-4450-8)