For example, fiber optic cables are harmless because they are just glass
But not all fiber optic sheaths comply with ROHS technology. The heat shrink tubing used for wiring that complies with ROHS is relatively expensive, so most of the materials used are not environmentally friendly. The adhesive used for internal bonding is almost harmless to the human body. However, the carrier of fiber optic communication is laser, and laser itself is harmful to the human body
In addition, during the production of optical devices, almost everyone uses industrial alcohol or acetone for cleaning. Both of these are harmful chemical reagents to the human body