Hearing protection safety sign - Ear protectors must be worn to ensure listening ability. This is an acknowledged standard around the world. This sign is often used to inform workers or visitors on specific sites what P.P.E. they require upon entering a Construction site, mine or even a workshop. This sign is used in conjunction with various other safety signs depending on what your requirements are, i.e (ZM 1) Eye protection safety sign also known as Goggles safety sign.