is designed to safely and hygienically smear-mark non-porous surfaces
with a harmless, non-toxic, water-resistant, invisible coating which only becomes visible
under Ultraviolet light. The grease is easily removed with
normal normal cleaning so when it remains after cleaning,
it would indicate the surface has not been cleaned effectively. Under UV
light these marks will glow bright green and is also suitable for use in
bathrooms, washrooms and kitchens.