CAS 103-16-2 Monobenzone

Monobenzone, also called 4-(Benzyloxy)phenol and monobenzyl ether of hydroquinone (MBEH)
Depigmentation
Monobenzone, also known as MBEH or Benoquin, is a topical medication used primarily for the permanent depigmentation of normal skin surrounding vitiligo patches in individuals with extensive vitiligo (affecting over 50% of the body surface area). It's a derivative of hydroquinone and works by causing the destruction or inhibiting the function of melanocytes, the cells that produce skin pigment. 
Here's a more detailed explanation:What it is: Monobenzone is a chemical compound, specifically the monobenzyl ether of hydroquinone, and is a topical medication
Important considerations:
Permanence:The depigmentation effect of monobenzone is generally considered permanent. 
Extensive vitiligo:Monobenzone is typically used for individuals with widespread vitiligo where depigmenting the remaining normal skin is a suitable approach.