Can I dispose of a metol based dev down the sink?

[Xícara]

Hi, I dispose of all my chemicals, ie. developers and fixers, responsibly with a fellow that services the local laboratories and extracts the silver. My usual roll film developer is PMK and I will continue to dispose of it in this way together with spent fixers. However I'm starting to use larger volumes of D76H developer to process sheet film and I'd like to know if this developer is safe, environmentally, to dispose of down the household sink. I guess not, but thought it might be worth asking here. Each litre of D76H concentrate has the following chemical amounts: 2.5g metol, 100g sodium sulphite and 2g of Borax. I'm using working solutions of 1:1 to 1:4.
Cheers,

 

[Don_ih]

It depends.

If your sink leads to a septic tank, you want to avoid putting used developing chemicals down there.

If your sink leads to a waste treatment plant, you can happily dump a small amount of any of your developing chemicals down there. You would need to produce a lot of waste to actually make a noticeable difference.

People will probably make reference to American government regulations. It should be noted those are only relevant to facilities that produce thousands of gallons of waste.

 

[Ian Grant]

In most countries it is permitted to dispose photochemistry to the foul sewer. That includes fixer if the Silver has been removed. I worked in this field as we imported and installed US made Silver recovery units. I also liaised with UK water board officials for laboratories.

Exceptions in Europe were the Netherlands and some other predominantly flat areas.

Ian

 

[Xícara]

Thanks @Don_ih and @Ian Grant . That's a good point about septic tanks, ours was only connected to the main sewage system a few short years ago. I believe that the sewage is treated but it all ends up in the local lake eventually and in which there's a commercial fishery. So I'll do some more research into regulations and into the local treatment facility. Thanks for your help.
Cheers,
Iain

 

[Dustin McAmera]

MSDSes that I can see for metol suggest that it isn't readily biodegraded, and that it is toxic to aquatic organisms. I can see (but not read without signing up to services I don't want) academic journal articles where people tried oxidising metol with peroxide, with or without a catalyst, and with or without UV light; that is, they experimented with destroying the metol chemically (in some effluent; I don't know what) before a biological stage of treatment.


Metol was Agfa's trade name for it; Kodak called it Elon; no wonder it's poisonous.

 

[Ian Grant]

MSDSes that I can see for metol suggest that it isn't readily biodegraded, and that it is toxic to aquatic organisms. I can see (but not read without signing up to services I don't want) academic journal articles where people tried oxidising metol with peroxide, with or without a catalyst, and with or without UV light; that is, they experimented with destroying the metol chemically (in some effluent; I don't know what) before a biological stage of treatment.


Metol was Agfa's trade name for it; Kodak called it Elon; no wonder it's poisonous.

Water boards here in the UK give licences for the daily disposal of quite large volumes of photochemistry. I'm talking many thousands of times the volumes of a home darkroom.

What is important is the dilution factor of any chemical discharge when it reaches a sewage treatment plant, you are going to be way more than 1 part per Million, more like Trillions. I had a meeting with the chief scientific officer of a large UK water company a few years ago, UK regulations are similar to US. It was pointed out that of all the large commercial labs only one was refused a licence to discharge, this was because it was in a small village and very close to the treatment plant, so insufficient dilution.

Ian

 

[JerseyDoug]

About ten years ago I attended a talk about the effect of the PFAS in fire fighting foam on water quality. (Our fire company has since changed to a fluorine-free foam.) At the coffee and chat session after the talk I spoke with the engineer who had briefly mentioned household chemicals. I told him I develop small quantities of photographic film at home and that in a year I use about 200ml of concentrated Rodinal and about two liters of working strength fixer. He was familiar with fixer but not the Rodinal. I explained that it was basically a mixture of Tylenol, washing soda and drain cleaner. He laughed and said the effect of pouring them down the sink would be, in his words, immeasurable. (He did ask if I wore eye protection when working with the Rodinal.) This was in New Jersey, USA.

 

[RalphLambrecht]

Hi, I dispose of all my chemicals, ie. developers and fixers, responsibly with a fellow that services the local laboratories and extracts the silver. My usual roll film developer is PMK and I will continue to dispose of it in this way together with spent fixers. However I'm starting to use larger volumes of D76H developer to process sheet film and I'd like to know if this developer is safe, environmentally, to dispose of down the household sink. I guess not, but thought it might be worth asking here. Each litre of D76H concentrate has the following chemical amounts: 2.5g metol, 100g sodium sulphite and 2g of Borax. I'm using working solutions of 1:1 to 1:4.
Cheers,

It won't kill the last wale in the ocean but it's always better to dispose of it through local haz-mat services. In Germany they make thiseasier because, there are free drp-off stations run by the cities!

 

[Don_ih]

If you brought it to the hazardous materials section of a dump around here, they'd dump it on the ground - along with everything else they get of no recyclable value.

 

[Philippe-Georges]

It won't kill the last wale in the ocean but it's always better to dispose of it through local haz-mat services. In Germany they make thiseasier because, there are free drp-off stations run by the cities!

The same over here, but you have to pay a very little fee, which is worth it as by this we are slowly getting a grip on pollution (which, soon or later, will cost us even more).

BTW, just out of curiosity: is dumping a Phenidone-Ascorbic Acid developer less hazardous for the environment?

 

[koraks]

is dumping a Phenidone-Ascorbic Acid developer less hazardous for the environment?

Depends on what the main problem is you're looking at. In general, the answer "should" be yes - I say "should" be, because these PC developers are sold as 'eco', so let's hope the net effect is indeed more 'eco' than for other developers.

You may notice a little cynicism in my words, which is due to the fact that determining the 'eco-ness' of a product is insanely complex, and it's virtually impossible to say if one developer is necessarily much better than the other based on its constituents alone. You can say something about it, but validating such claims is virtually impossible. https://en.wikipedia.org/wiki/Life-cycle_assessment

To come back to your question: you limit the scope to 'dumping', but this still leaves the question how and where it will be 'dumped'. Do you mean chucking the used developer into the backyard, into nearby woods or fields, into a sewer system, into a septic tank or at a local waste disposal station? You'd have to consider these options and then work out for every constituent of the used developer how these materials fare after the dumping is done - do they linger about and dissipate through the environment? Do they seep into deeper soil layers and perhaps into the water table? Are they degraded by microbial life, and if so, how fast and by which species, and how likely is it these species are around in the (eco)system where the dumping took place? What is the energy balance of the disposal method (think of e.g. incineration of liquid waste and the logistics involved) and any byproducts and side-effects?

And that's just dumping. Now look at the actual makeup of the developer, how the ingredients are produced and what the environmental (and perhaps social??) impact of the production and logistics of those ingredients are.

At various places in the process you'll have to make judgement calls about how to weigh effects. If you compare a borate-based PC developer to a borate-free MC developer, how do you weigh the potential impact of borates vs. the difference between phenidone and metol? How do you weight the energy impact of both options vs. their environmental impact? Which dimensions of environmental impact will be deemed more or less important? The only truthful answer here will be that a quantitative assessment will always fall short of being accurate, so you're stuck with a qualitative or mixed method assessment that turns out to be quite complex to answer.

The question you ask seems to simple, but the truth is that it's impossible to answer.

 

[Nitroplait]

You may notice a little cynicism in my words, which is due to the fact that determining the 'eco-ness' of a product is insanely complex,

Agree about the complexity.

If you ask the manufacturer what "eco" means, they'll probably say "economical" to avoid green-washing charges.

 

[Xícara]

I've asked a neighbour that's an environmental scientist. He's going to ask some colleagues for me about agencies and regulations. Hopefully I'll encounter a "least bad" option for disposing of it. When I asked the silver extraction fellow what to do, he said to tip it down the sink with lots of water. So, that's probably what he does anyway after the extraction.... If I can find a better solution, I'll do it.

 

[grain elevator]

It won't kill the last wale in the ocean but it's always better to dispose of it through local haz-mat services. In Germany they make thiseasier because, there are free drp-off stations run by the cities!

I have doubts whether it's actually more ecologically benefitial to incinerate used developer (big energy input). I try to minimise impact by using ascorbate developers except for lith printing. But my municipal waste treatment company wants all photo chems brought to hazmat pickup.

 

[grain elevator]

tip it down the sink with lots of water

I've never understood this advice which I frequently encounter. There's plenty of water in the sewage system which will dilute it, a few dozen liters or so of water wasted on purpose can't possibly make a difference in all but the smallest sewage systems?!

 

[Agulliver]

Photo chemicals designed for consumer use are also designed to be safe to wash down the sink/toilet. Unless your local water treatment is woefully inadequate, it's perfectly fine. Just think of the small amounts of photo chemicals this hobby generates compared to 40 years ago when more people had darkrooms, more people were shooting film.

Now a commercial lab, even a small one, will need a licence....and it's been pointed out even that isn't usually difficult to get.

The situation in Germany has been mentioned before, I am baffled but am drawn to the conclusion that either the committee which came up with the regulations was wholly uninformed....or German water treatment is woefully inadequate. I find the latter hard to believe.

Bottom line is, the chemistry is *designed* to be safely tipped down the sink.

 

[Don_ih]

Photo chemicals designed for consumer use are also designed to be safe to wash down the sink/toilet.

They're designed to develop film or prints, fix film or prints, bleach film or prints, or tone prints. It's coincidence that they can mostly be dumped down any drain without worry. Direct human toxicity is more of a concern - and that wasn't always the case. Get a bottle of Kodak Film Cleaner and huff a drop of it. These companies were forced to stop using certain compounds.

 

[Philippe-Georges]

They're designed to develop film or prints, fix film or prints, bleach film or prints, or tone prints. It's coincidence that they can mostly be dumped down any drain without worry. Direct human toxicity is more of a concern - and that wasn't always the case. Get a bottle of Kodak Film Cleaner and huff a drop of it. These companies were forced to stop using certain compounds.

Yes, like CCl4, TCE and Formaldehyde, which I used in the darkroom by liters at the time...

 

[grain elevator]

or German water treatment is woefully inadequate. I find the latter hard to believe.

Waste water treatment in Germany, like many other places, to my knowledge is mostly such that the water gets cleaned of substances that can settle out if it, a lot of stuff is reduced or oxidised, and there may be limited filtering mostly through sand filters. What remains in solution after that stays in the water, e.g. sulfates as a result of the sulfite in photo chems. There are usually no carbon or membrane filters or anything like that.
Although especially the oxidative processes do a lot more than one might expect, people tend to overestimate what waste water processing does.

 

[Vaughn]

The university and the city had Dektol tested and found it safe to run thru the sewer treatment system of the city -- which is a semi-well known sewer treatment facility and very careful about what goes thru the system.

 

[MattKing]

Photo chemicals designed for consumer use are also designed to be safe to wash down the sink/toilet. Unless your local water treatment is woefully inadequate, it's perfectly fine. Just think of the small amounts of photo chemicals this hobby generates compared to 40 years ago when more people had darkrooms, more people were shooting film.

They're designed to develop film or prints, fix film or prints, bleach film or prints, or tone prints. It's coincidence that they can mostly be dumped down any drain without worry.

Part of the design criteria for the home or small volume user packaging of photographic chemicals is, indeed, the fact that the volumes produced can be relatively safely handled and disposed of by the intended user.
If you are buying your photo-chemicals in 40 gallon drums, the environmental and regulatory concerns are different than if you buy a small bag of powder developer one every several months.

There are two parts to the answer for the OP's question:
1) how deleterious is disposing of the working solution developer; and
2) do the OP's local regulations prevent what the OP wants to do.
The two questions are different.
And the answer to either or both of the questions very often depends on the volumes involved.

 

[pentaxuser]

Surely the answers we are giving and standpoints we are adopting is dependent on what the "water authorities" say needs to happen in each country's case but this may have little or no relevance to Brazil

In practical terms unless we live in Brazil and maybe even his area of Brazil given its size as a country we cannot give any useful answers

pentaxuser

 

[Xícara]

No, it's been helpful knowing what happens elsewhere - thanks to everyone. I've just been given the name of the main authority to contact here - "Agência Nacional de Águas e Saneamento Básico" - so will get in contact!
Cheers,

 

[Don_ih]

Part of the design criteria for the home or small volume user packaging of photographic chemicals is, indeed, the fact that the volumes produced can be relatively safely handled and disposed of by the intended user.
If you are buying your photo-chemicals in 40 gallon drums, the environmental and regulatory concerns are different than if you buy a small bag of powder developer one every several months.

Not to pick too much, but that's a bit silly. The chemicals are the same if in a small packet or a 40-gallon drum. Selling a packet that makes a litre of developer has nothing to do with whether or not it can be safely dumped down the drain and all to do with the fact that a home user doesn't need and would never possibly use a 40-gallon drum of it.

 

[MattKing]

Not to pick too much, but that's a bit silly. The chemicals are the same if in a small packet or a 40-gallon drum. Selling a packet that makes a litre of developer has nothing to do with whether or not it can be safely dumped down the drain and all to do with the fact that a home user doesn't need and would never possibly use a 40-gallon drum of it.

In many cases, the problems do come from quantity and the level of dilution.

A good illustration of this is someone who has run into problems because they've increased greatly the input to a septic system that has done its job well for years with lower, more typical quantities and varieties of household waste.
The same applies to municipal sewer systems.

A reasonably robust waste management system is capable of handling certain amounts of dilute chemicals without harm. Higher quantities may overwhelm that.

Many things are safe if quantities are low and dilutions are high, but dangerous if quantities and concentrations are high.