Hygiene is important in any workplace, but I assume especially so in a place that "sells" beauty.
A dirty work environment will reflect badly, and custom will soon dry out.
Also think about all the hair, dead skin and debris. A perfect breeding ground for lice and other bugs. If you don't keep standard high, environmental health officers could even close your salon down!
Keeping your scissors, brushes, combs and other utensils sanitised is also highly important. I would be outraged to think a salon might be spreading germs and dandruff by re-using equipment without the proper procedures in place to maintain hygiene... Yuck!!