What is "benzophenone-n"

Benzphenone-1 – benzophenone-12 (BP-1 –BP-12) are UVA/UVB absorbers. Most of them are used in sunscreens.

• Benzophenone-1 (2,4-dihydroxybenzophenone)
• Benzophenone-2 (2,2',4,4'-tetrahydroxybenzophenone)
• Benzophenone-3 (oxybenzone)
• Benzophenone-4 (sulisobenzone)
• Benzophenone-5 (sulisobenzone sodium)
• Benzophenone-6 (2,2'-dihydroxy-4,4'-dimethoxybenzophenone)
• Benzophenone-7 (5-chloro-2-hydroxybenzophenone)
• Benzophenone-8 (dioxybenzone)
• Benzophenone-9 (sodium 2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5,5'-disulfonate)
• Benzophenone-10 (mexenone, 2-hydroxy-4-methoxy-4'-methyl-benzophenone)
• Benzophenone-11 (benzophenone-2 and benzophenone-6)
• Benzophenone-12 (octabenzone, used to protect plastics)