Advice for safe mixing of powdered chemistry

I've always used liquid chemistry for the convenience and the safety of not having to deal with powders. But it's getting harder to get liquid chemistry shipped to me and powdered chemicals are less expensive and easier to store.

My only concern with powders is mixing them safely without inhaling airborne powder. What are most people using to protect themselves when mixing powdered chemistry? Is a particle respirator the best option?

If you are talking about something like commercially packaged products like D-76, ID-11 et al for the low volume user, just ensure decent ventilation, reasonable levels of prudent care, and a clean working area.
It is designed to be used in home darkrooms, schools and workplaces, not Hazmat sites.
If you are doing this daily in a high volume lab environment, I might consider a respirator, but probably not.
Don't fling the stuff around, but otherwise just exercise normal care.
I've been using powders and liquids about equally, for over 50 years.

I never thought about this and never had problems.
However, if you want to be sure, take the chemicals from Adox - their powdered chemicals are dust free.
They have for example XT-3 (X-tol) and D-76 as well as some more developers and also powdered stop and fixer, all with the captura technology.

I too have not had problems mixing dry chemicals by following the instructions carefully and having good ventilation.

No worries with Kodak, Ilford etc. If you are concerned wearing a simple dust mask. Like others, I've been mixing up powders for decades.

Never worn a mask mixing for over 40 years. But surely you have a covid mask laying around. Just be aware.

If you're concerned about safety or prone to skin irritation, you may want to use nitrile gloves as certain ingredients in developers (hydroquinone) can cause contact dermatitis (annoying itch). But for standard chemistry like D-76 or fixer, you can mix from powder without ever kicking up enough of it to get on your hands or in your lungs. If you're really concerned, gloves, glasses, and a mask are more than enough to protect against common photo chemicals.

There was a thread a while ago from someone concerned about mixing catechol developers, a chemical that IMO is significantly worse than the "normal" stuff like D-76, stop, and fixer. https://www.photrio.com/forum/threa...us-for-someone-untrained-in-chemistry.209505/

To add what dpurdy said, if you want to get kn95 masks, I get mine from a company called Bonafide Mask. The do have discounts on their site alot of the time (they have one for 25% off on their site) so a 10 pack will be less than $10 bucks for this one: https://bonafidemasks.com/Powecom-kn-95/

Thanks for all the replies. The powdered print developer I'm planning on using is Ethol LPD. I assume that one is no worse than things like D76 and XTOL. I do have a bunch of N95 masks around so maybe I'll wear one just to be sure.

logan2z said:

Thanks for all the replies. The powdered print developer I'm planning on using is Ethol LPD. I assume that one is no worse than things like D76 and XTOL. I do have a bunch of N95 masks around so maybe I'll wear one just to be sure.

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Unless I had serious pre-existing health concerns, I wouldn't bother with the mask.
And I never have.
This sort of stuff is designed to be used in household or workplace environments.
If you can handle things like laundry detergent and spicy cooking, you can handle common photo chemicals.
And as for powder vs. liquid, the only photo-chemical I take extra special care with is a liquid - selenium toner.
That and particularly smelly ones, like certain toners.
I take normal care with all the rest.

MattKing said:

If you are doing this daily in a high volume lab environment, I might consider a respirator, but probably not.

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Well, depending on what one considers high-volume, what they call "engineering controls" are preferred. These would be ventilation systems, or maybe fume hoods. Plus protective gear for the mix operator, but it's seen more as a secondary protective stage.

FWIW, in the US an agency known as OSHA has oversight over this sort of thing (in the so-called workplace, and only in the workplace). Something not well-known is that it's not permissible to just stick some employee into a respirator. My former QC department, or later a spin-off of same used to oversee this sort of thing. First thing was a doctor's note that it was permissible for the specific person to actually use a respirator (some people might have a physical problem with the slight suction, or perhaps a claustrophobic reaction to the mask). After this they had to have training on the fitting and use of a respirator, including how to clean and sanitize afterwards. (Fwiw no facial hair allowed in the sealing area.) In places where we didn't think a respirator was necessary we would actually do air sampling - the person doing the work would wear a battery powered "sampler" on their belt; a small tube comes up near their "breathing zone," not unlike those tiny microphones that entertainers sometimes wear. At the end of the day the captured "whatever" is analyzed by a specialist lab, etc.

I dunno how other places would do it, but this was our operation. Same thing in our three "satellite" labs. Including one in Canada where essentially the same laws existed, just under a different authority.

All this not really applicable to a guy at home. Personally I would probably just hold my breath while pouring in the powder, then go to the next room to breathe again. Then wait a while for the airborne dust to settle a bit. Actually, I would probably read the MSDS (material safety data sheet) to see what IT says, although it's probably overkill for an occasional home user.

FWIW a guy named Richard Henry wrote a book about "Controls in Black and White Photography," or something similar. He also had concerns about breathing in chemical dust. His method fir D-76, as I recall, was to make a diagonal cut in the corner of the envelope, then submerge that corner whilst pouring in the powder. So... why not?

Too much info? Yeah, probably. But what the heck.

Mr Bill said:

FWIW a guy named Richard Henry wrote a book about "Controls in Black and White Photography," or something similar. He also had concerns about breathing in chemical dust. His method fir D-76, as I recall, was to make a diagonal cut in the corner of the envelope, then submerge that corner whilst pouring in the powder. So... why not?

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This works well - particularly with the newer plastic bag packages.
You can actually rinse the packages out into the mix, meaning no waste.

MattKing said:

This works well - particularly with the newer plastic bag packages.
You can actually rinse the packages out into the mix, meaning no waste.

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That's a good point, to rinse out the package.

logan2z said:

Is a particle respirator the best option?

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If you're concerned, a typical sanitary facemask - the FFP2 kind we all have worn hundreds to thousands of by now would be fine and they're easy to obtain.
For mixing a single bag of D76, XTOL etc once in a while, I never bothered with a mask. Mucking about with several kilos of pure, finely powdered developing agents...uh yeah. But that's probably not your use case.

reddesert said:

If you're concerned about safety or prone to skin irritation, you may want to use nitrile gloves

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Right, I always use nitrile gloves when mixing chemistry, developing film and making prints.

koraks said:

If you're concerned, a typical sanitary facemask - the FFP2 kind we all have worn hundreds to thousands of by now would be fine and they're easy to obtain.
For mixing a single bag of D76, XTOL etc once in a while, I never bothered with a mask. Mucking about with several kilos of pure, finely powdered developing agents...uh yeah. But that's probably not your use case.

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Thanks, there's no shortage of N95 masks around our house so I think I'll use one just to be on the safe side. But I like the suggestion made by @Mr Bill to empty the package while the open corner is submerged in water. That seems like a good approach to minimize airborne powder.

Just to continue a theme, the kind of B&W photography chemicals sold to the public are designed to be used in a darkroom/bathroom/kitchen by untrained people. Indeed unless you get into reversal processing the chemicals used in dev and fix will be considerably less hazardous than those in a box of hair dye and probably less hazardous than washing powder.

Unless you have a pre-existing respiratory illness there's no need to take any precautions beyond common sense. for 99% of people, anything short of huffing the powder or chugging the solution won't be harmful.

If you do have a respiratory condition, there's no harm whatsoever in a regular cloth face mask of the kind we were wearing for covid a few years ago. Some people find that over time they develop (pun intended) contact dermatitis from developers. In which case nitrile gloves or even regular dish washing gloves are advised.

One of my partners has multiple allergies as well as "rapid onset life threatening asthma" so I mix the powders for her. She does itch when using thiosulphate fixer so wears gloves.

Just put the open package close to the surface of the water and pour it all in. That will create the least possible amount of dust.

Mr Bill said:

...

FWIW a guy named Richard Henry wrote a book about "Controls in Black and White Photography," or something similar. He also had concerns about breathing in chemical dust. His method fir D-76, as I recall, was to make a diagonal cut in the corner of the envelope, then submerge that corner whilst pouring in the powder. ...

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I've been doing this for years. No dust. Works on every type of packaging I've ever had. And, as mentioned, you can rinse the package.

With other dry chemicals that come in jars or cans, slow and easy is the rule. I find having the ventilation going and wearing a simple Covid mask does the job quite well.

Best,

Doremus

Doremus Scudder said:

I've been doing this for years. No dust. Works on every type of packaging I've ever had. And, as mentioned, you can rinse the package.

With other dry chemicals that come in jars or cans, slow and easy is the rule. I find having the ventilation going and wearing a simple Covid mask does the job quite well.

Best,

Doremus

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Sounds good, this is what I plan to do.