Ascorbic Acid – Vitamin C Powder
Use in the reduction of potassium dichromate. Therefore you can threat waste dichromates with Vitamin C (ascorbic acid) this changes the dichromate to a stable, (changes wash water from yellow to clear) much less toxic form that can go down the drain. Any other residual sensitizer can also be treated with ascorbic acid (vitamin C)– this turns the sensitizer green indicating a conversion to trivial chromium – lowering the toxicity. This is then safe to dispose all material contaminated with dichromate in the rubbish.
NB: When handling dry dichromate chemicals wear gloves, face-mask and eye protection. When working with the dichromate solution gloves must be worn.