Confirm the contents of a waste chemical bottle before pouring anything into it. Soak up spills, clean up counters, and wash down the darkroom sink properly. Dispose of paper towels carefully. Use the shower only in extreme emergency because of the fifty gallons of water it dumps into the darkroom. Report any accident, no matter how slight, to your TA or other supervisor right away.
Mineral oil is essentially inert, and in pharmaceutical purity is used to treat gastric distress.
Pyrogallol is a component of several developers we will use in later labs. Our ascorbic acid is not food grade, so don't eat it. It is used in several developers. Sodium Phosphate Dibasic , another developer component, is a minor skin and eye irritant. Bleaches EDTA bleach contains EDTA, which should not come in contact with the skin, and Potassium Bromide, which is harmful if swallowed.