Employees Must Wash Hands Before Returning to Work Sign. This sign is written in English Language and the sign is made of acrylic material. This sign features pressure sensitive adhesive backing for easy mounting. White lettering on black background. Let your customers know that hygiene is a staff priority with this black and white employee hand washing sign! Ensuring that all your staff members follow proper sanitation habits is crucial for the success of your business, and this sign is the perfect way to do that. Keep both guests and health inspectors happy with this hand washing sign!