The very small amount of volatile substances produced when eyelash extension glue thickens and hardens are mainly cyanoacrylate (cyanoacrylate monomer/polymer) When they adhere to the surface where the eyelash extensions are attached, they can be seen by the naked eye as a whitening phenomenon. The frequency of whitening varies depending on the characteristics of the glue, but it is especially common during the rainy season and summer when humidity is high. Also, inadequate or unsanitary pretreatment This phenomenon is also often seen when artificial hair is used or when washing the face or taking a bath, etc. are performed immediately after treatment. This phenomenon tends to occur when there are problems with ideal curing conditions, such as excessive moisture or lipid stains that promote a rapid curing reaction of the glue, which may cause a decrease in staying power and itching. This phenomenon is particularly likely to occur during the rainy season and summer months, so care must be taken to control humidity during these times.