View Full Version : A question for any Experienced Chemists/Toxicologi

Bobby Sandstrom
24-Jul-2005, 15:57
Please answer only if you know for sure...

After Processing with Pyrocat HD (approx 1 liter) if I further dilute it with say 3 gallons of water would it dissolve the harmful chemicals to a degree that I might then pour it down the drain without causing any harm?

Thanks for your help.

Jorge Gasteazoro
24-Jul-2005, 16:05
In haz waste disposal and environmental law we had a saying that went "dilution is not the solution." You are still introducing the same amount of harmful chemical. Let me give you and example. If I put 10 gr of sugar in a glass with 50 ml of water and have you drink it, you effectively drank 10 grams of sugar. If I put the same 10 grams in a glass with 200 ml of water and have you drink it, once again you "drank" 10 grams of sugar.

Having said that, The chemicals in Pyrocat developer (even in the stock solutions) are very well bellow the dangerous levels, after you dispose of them, oxidizer and bacteria will break down the most harmful one (pyrocatechin) until eventually it will become simple carbon compounds like methane.

Dont worry and dump away, no need to dilute.

Gene Crumpler
7-Aug-2005, 20:17
Jorge is correct. By the time your quart of developer gets to the WWTreatment plant, it will be diluted by anywhere from 200,000 to 100,000,000 gallons of waste water. Heavy metals are the real problem as they do not biodegrade and end up in the primary, secondary and terteary(sp?) sludge. Disposing of the sludge with heavy metals is the real problem in waste water treatment. See 40 CFR Section 503, Part E (I wrote this).