Compounds of sulphur, silver and selenium (photo chemicals) decompose into those elements or other compounds of those elements. Elements (carban, hydrogen oxygen, sulpfur, silver, selenium and many others) are not biodegradable.
I don't know where I might have given the impression that I'm not familiar with the Periodic Table. I understand perfectly well that elements by definition cannot be broken down or transformed into other elements, excepts by atomic fusion or atomic fission.
Most of these elements are already in the soil through natural processes, and the quantities that are in the soil will vary enormously depending on location and geology. A major health concern around the world is trace element deficiency in the diet due to the soil not
containing sufficient quantities of trace elements. Even in wealthy Western countries, monoculture farming practices tend to cause the soil to become depleted of essential trace elements which are not included in the chemical fertilisers that modern farming practices rely upon. You've probably heard of the disastrous effects of iodine deficiency in countries like Bangladesh where the soil has so little naturally occurring iodine.
Stop bath, for instance, is acedic acid (vinegar). You can make salad dressing from vinegar and safely eat it. You can drink acedic acid and get burned, sick or die.
Let's get things in perspective. You could also die (so I've heard from a qualified nutritionist) if you were to eat a cupful of apple seeds. That doesn't stop you eating apples, does it? Have I suggested anyone drink their waste stop bath on the grounds that it's similar to vinegar? Of course I haven't. What I've suggested is that you dilute it heavily and pour it into a compost filled pit. If you find the soil is becoming too acidic to grow things, then add a bit of lime. Every gardening novice knows that.
Photo chemicals also react with ecah other to produce different chemicals.
Indeed! But I don't believe plants automatically take up whatever compounds are in the ground. If there's an increase in selenium, or iodine or molybdenum in the soil, then some plants will take up a greater quantity of those trace elements, but I doubt that digging potassium cyanide into the ground and growing tomatoes would result in deadly poisonous tomatoes, otherwise it would have been the plot of an Agatha Christie novel .
Selenium toner stinks, but it is not the selenium you are smelling.
Quite so! But I wouldn't be surprised if the odd selenium atom is carried up in those vapours. Perhaps the message here is, if you spend a lot of time in the darkroom using selenium toner, you are less likely to be suffering from selenium deficiency. In which case, give those selenium enriched tomatoes to friends who don't spend time in a darkroom .
The chemists at Kodak are arguable not studid or ignorant but may know what they are making and how to dispose of it better than the users, or readers of LL. Kodak recommends sending wastes to sewage treatment plants, period. They do not suggest composting in the garden. Kodak does not say you can safely compost the stuff in small quantities once or so.
My method is only for sensible people. This thread is about a specific set of circumstances. Someone living away from the city centre, on a larger than average block of land, who is probably only going to continue darkroom processing for a very few years at most and who is not going to produce large quantities of waste. His local council does not have facilities for disposal of small quantities of waste.
The chemists working at Kodak are probably not agricultural chemists nor necessarily waste disposal experts. As I've mentioned before, such generalised warnings on labels are partly for legal reasons. They are not designed to be a practical and detailed guide to meet every set of circumstances.
(I did check on the internet and my great, great, great, grandfather was a rapist and a murderer and Australian. However, this condition wasn't his fault because he was from England where his father didn't get enough selenium. FYI my great, grandmother was a modest womwn traded by Australia to the USA. They had no use for her but needed more murderers. Australia got one plus a draft pick.)
Nice story. I didn't know America contnued to accept British convicts, whether indirectly from Australia or not, after the War of Independence. They then relied upon African slaves, didn't they. Perhaps we should re-write history.