What does yellow mean?

Biohazard Waste sign at Summerland Memorial Health Centre

I obsess about colour and the associated meanings. I've written at length about the various and often confusing meanings associated with the colour red.

Today I'm looking at yellow. In Canada yellow is associated with the telephone book (Yellow Pages) and also cancer (Canadian Cancer Society). But for the medical profession yellow is to be avoided at all costs. The yellow garbage bag is how the biohazard waste is disposed of.

I wonder how that affects the habits of medical people shopping at Loblaw's stores?

Packaging for Loblaw's "no name" Chicken with Garlic Butter

It would be an interesting area to research.