Recommendations for buying pyrogallol?

[juan]

Are the masks sold in the paint sections of big box stores, those with organic vapor filter elements, sufficient for mixing photo chemicals?
Juan

 

[Alan Johnson]

Yes IMO, I have used such a mask , also ensuring good ventilation to carry away vapours from the room.
Don't knock the pot over as any spill will need extensive cleaning up.

 

[Wayne]

Quite often, if claims are made contrary to the accepted practice, some evidence is presented, but this has not been done here.
Further the misfortunes that are to befall the victims are not discussed.
I have quickly looked up the LD50 for the substances discussed and the results seem to support Mr King's assertion.
Hydroquinone- mouse 350mg/kg, rat 320mg/kg
Pyrogallol-mouse 570mg/kg, rat 790mg/kg.
Catechol-mouse 100mg/kg, rat 390 mg/kg.
This is only a quick look but IMO since it is you making new claims you should provide any evidence.
It is not sufficient evidence to ban hydrogen hydroxide that the results of LD50 tests are not to your satisfaction, they are very often all there is.

yea I was looking at MSDS myself yesterday and finding information that seemed contradictory to what I have seen in the past. The LD50s indicate hq is more deadly to small mammals than pyro which is not what I recall, but I OTOH I also found msds that said no neurological effects are known for pyro which numerous other sources will contradict. The information I used in the past placed hq in a different (reduced) risk category, and it wasn't all that long ago but I don't have time to find that info again right now. Maybe the experts have changed their minds

 

[Gerald C Koch]

Please look at post #8* which contains a link for the pyrogallol MSDS. Specifically Section 11 after the rat/mouse/rabbit data. The HUMAN LDLo is 28 mg/kg. We can argue 'til the cows come home about data for lab animals but we are humans and the toxicity data (when available) for us is very different. The danger for us as photographers is not from oral ingestion (at least I hope everyone is not eating this stuff) but from skin absorption. Our livers do a very good job of detoxifying what we eat. For example tannic acid is a condensed polyphenol. We get it everyday in tea and coffee. However when applied to abraded skin it can cause systemic poisoning. Toxicology is a very complex subject.

Pyrogallol is the most toxic of the B&W developing agents. In addition it is readily absorbed thru the skin. That is all that needs to be considered. Ignore the warning if you wish.

As far as hydroquinone is concerned creams containing 4% are routinely sold over the counter. Very little danger except in extreme cases as noted previously where the entire body has been covered by the cream repeatedly. Skin lightening creams are very popular in Africa. The danger from hydroquinone is the effect on the red blood cells a condition known as methemoglobinemia. This condition prevents the cells from absorbing oxygen. The condition disappears with time as new blood cells are created. An entirely different mode of toxicity from pyrogallol.

https://en.wikipedia.org/wiki/Methemoglobinemia

 

[Alan Johnson]

All you have done is to give one LD50 human for Pyrogallol, no data for Catechol or Hydroquinone.
There are no references for your other claims.
See also The Darkroom Cookbook 3rd ed p 66 "PMK :Thirty Years on by Gordon Hutchings".
Used sensibly it does not appear to present a hazard.

 

[Gerald C Koch]

All you have done is to give one LD50 human for Pyrogallol, no data for Catechol or Hydroquinone.
There are no references for your other claims.
See also The Darkroom Cookbook 3rd ed p 66 "PMK :Thirty Years on by Gordon Hutchings".
Used sensibly it does not appear to present a hazard.

So after two or more hours of research on the net. What was particularly maddening was that there is no consistency between sources. One article will cite NIS values while another EU values, etc, etc. So it was extremely difficult to find a LDLo for humans for pyrogallol, hydroquinone and catechol.

Toxicity data for catechol is hard to come by. https://en.wikipedia.org/wiki/Catechol

Toxicity classifications are given here. https://en.wikipedia.org/wiki/Toxicity_class

Another citation for pyrogallol is here http://chem.sis.nlm.nih.gov/chemidplus/rn/87-66-1

For catechol https://www.spectrumchemical.com/MSDS/TCI-M0121.pdf

For hydroquinone http://terpconnect.umd.edu/~choi/MSDS/Sigma-Aldrich/HYDROQUINONE.pdf

So finally we have a LDLo for humans of catechol: 43 mg/kg, hydroquinone 29 mg/kg, pyrogallol: 28 mg/kg.

The LDLo's are all for oral ingestion and not skin absorption.
.
This frankly surprised me as I was given to believe the catechol LDLo would be higher (less toxic) and for hydroquinone even less toxic. But these are the values I finally found. I would point out that all the MSDS information stressed the ease of absorption of pyrogallol.

 

[CropDusterMan]

Used sensibly it does not appear to present a hazard.

Exactly. Too much worry-wart doom and glooming going on here. Gerald, have a little faith that
others out there have some common sense to protect themselves and use a product safely.
You're sounding like a hall monitor. The guy originally asked where he could buy it, not be
given the 3rd degree on the subject FCS.

 

[Wayne]

Exactly. Too much worry-wart doom and glooming going on here. Gerald, have a little faith that
others out there have some common sense to protect themselves and use a product safely.
You're sounding like a hall monitor. The guy originally asked where he could buy it, not be
given the 3rd degree on the subject FCS.

Gerald was responding to some incorrect information that was posted. Would you prefer that incorrect information on chemical risks/safety go unchallenged, to avoid worrying people?

 

[calebarchie]

Now if everyone who had something to say about safety also provided a supplier with that disclaimer....

 

[CropDusterMan]

Gerald was responding to some incorrect information that was posted. Would you prefer that incorrect information on chemical risks/safety go unchallenged, to avoid worrying people?

Look at this entire thread...it's taken the form of a fatherly figure handing down this all-seeing wisdom about the
perils of working with a dangerous chemical. Any adult who handles any chemical with reckless abandon without
consulting a label is a moron. This entire thread has taken an alarmists position.

jvoler's original post:

"I'm looking to make my first batch of 510 pyro and wonder where folks here get their pyrogallol.
I know the Formulary carries it - are there any other sources anyone would recommend? Thanks".

 

[Gerald C Koch]

I have updated my previous post to contain information about hydroquinone. As I said the information was hard to come by. We just don't use people as lab rats. For the best information for humans pigs would be a better test animal since their physiology is closest to humans.

BTW I was not trying to be alarmist by providing some helpful warnings. That said I don't think that those who find fault had a friend who spent 3 days in hospital for methemoglobinemia caused by similar chemicals. It's all too easy for some folks to blow things off until one sees what can happen. So if you love staining/tanning developers by all means use them. But be aware of the dangers.

 

[Alan Johnson]

Since I have now found this EU data I might as well post it.
As Gerald says, Catechol (section 3.2.4), which is classified as Acute Tox 3 is indeed less than Pyrogallol , which is classified as Acute Tox 4.
Not really relevant here but might be of interest to catechol users.Also, the wearing of gloves is indicated.
http://echa.europa.eu/documents/10162/13626/clh_report_pyrocatechol_en.pdf
https://extranet.fisher.co.uk/chemicalProductData_uk/wercs?itemCode=10773611&lang=EN

 

[Gerald C Koch]

Thanks Alan!!! I looked and looked but could not find this data.

 

[RobC]

can anyone cite any cases where photographers have been conclusively proved to have suffered ill health from photo chemicals. Not hearsay or anecdotal examples but proven medical cases. Are there any stats on this anywhere.

 

[Gerald C Koch]

can anyone cite any cases where photographers have been conclusively proved to have suffered ill health from photo chemicals. Not hearsay or anecdotal examples but proven medical cases. Are there any stats on this anywhere.

Nothing modern that I have seen because I suspect people are more careful today. I have read that around the early part of the 20th century when safety was becoming an issue it was observed that photographers had a shorter lifespan than other occupations. This was attributed to the chemicals they used every day. But then too they were often blowing themselves up trying to reclaim silver using nitric acid. Nitric acid, silver and organic material (emulsion) create silver fulminate a very shock sensitive explosive. Earlier daguerreotypists frequently died of mercury poisoning. It was often noted that heir gold watches and chains would be silver at the end of the day from the mercury vapor. By the next morning the gold was yellow again. The mercury works itself into gold metal items and disappears to the eye.

You would have to find information from before machine processing was done and every photographer did his own developing. It would be difficult since photographers just don't suddenly die. Any effects are gradual over a period of time. I wonder if something like OSHA would have such statistical information. I know that they have it for morticians. Formaldehyde in embalming fluid will get you eventually. I too would be interested in any evidence.

The problem with pyrogallol and other chemicals is not only their acute toxicity. I doubt that anyone is going to fall over dead, but their cumulative effect. Among other things his can lead to cancer and organ damage. Hence the need for long term data. See Section 11 in the following MSDS which lists possible mutagenic and reproductive effects and the danger of chronic exposure.

http://www.jmloveridge.com/cosh/Pyrogallol.pdf

 

[Wayne]

can anyone cite any cases where photographers have been conclusively proved to have suffered ill health from photo chemicals. Not hearsay or anecdotal examples but proven medical cases. Are there any stats on this anywhere.

There are numerous cases where photo chemicals have been implicated in health problems but determining an exact cause "conclusively" is often difficult or impossible.

"Darkroom disease" is a well known cluster of symptoms among radiology lab workers that has no definite cause but been linked to chemical x-ray processing. Many photographers have also reported developing ill effects such as allergies and sensitivities from darkroom work. These can range from dermatitis to respiratory problems.

 

[Alan9940]

After 40 years in the darkroom, the most health issues I've ever heard of involved skin sensitivity to various chemicals and a few cases of respiratory issues (as Wayne suggested above.) I'm sorry, but it's just too much of a stretch for me to think Edward Weston's Parkinson disease had anything to do with his use of photo chemicals, as suggested in this thread. Of course, we'll never know but I just can't get there.

I've been mixing my own film and paper developers and all solutions required for pt/pd printing for about 20 years now, and I've never had a spill, powder chemical accident, etc. I will confess, though, that I'm a lot more careful in the darkroom nowadays then I was back when I started. Back 25 - 40 years ago I didn't think anything of putting my hands into all sorts of photo chemicals; today I wear nitrile gloves when working with any photo chemical--either raw or in solution--and proper face/body protection when mixing. Since I'm not willing to give up processes and formulas that I've come to rely on, I'll have to hope that I'm being sensible and careful enough...

This thread may have veered off a bit from the OP question, but it has been interesting and IMO very useful information for anyone considering "mixing their own."

 

[Gerald C Koch]

Well accidents do happen I know of a particularly expensive one. I shared a lab with another grad student. The department had purchased a few milligrams of a particular rare iron isotope for $800. At the end of any experiment you could return the isotope to Oak Ridge for a refund. During a transfer to another container the student sneezed. Bye, bye $800, a lot of money in 1962. The school first threatened to take the money out of his stipend but later relented. This has to be the most expensive sneeze in history.

 

[Gerald C Koch]

can anyone cite any cases where photographers have been conclusively proved to have suffered ill health from photo chemicals. Not hearsay or anecdotal examples but proven medical cases. Are there any stats on this anywhere.

In her biography of Ansel Adams Mary Alinder calls Parkinson's the photographer's disease citing both Edward Weston and Margaret Bourke-White. You will now find references to this term on the net. Adams did not have Parkinson's but an autopsy after his death revealed that his body was riddled with cancer. (During his last years Adams worked long hours in his darkroom making prints.) To a list of those with PD add Alan Babbitt. I am sure that there are others.

The term Parkinson's disease is an umbrella term for several conditions with similar symptoms. There appears to be a genetic component to some cases. There is growing evidence that environmental toxins also play a role. Implicated so far are pesticides and very strongly organic solvents in particular trichlorethylene. Workers in the dry cleaning business, which primarily uses trichlorethylene, also have a higher incidence of Parkinson's. So it would be logical that other substances could play a role, ie pyrogallol and other developing agents. I wasn't able to find any specific studies of darkroom chemicals but sentiment seems to be leaning towards them.

 

[RobC]

It's all anecdotal evidence where people find what they're looking for. e.g. I'm a photographer and know a photographer who died of parkinsons. It must have been the chemicals he was using. Fact is nobody really knows.
I'm not suggesting these chemicals aren't bad for us if misused but if treated with common sense and basic safety precautions, then I don't think we should fear them. If they were so bad you wouldn't be able to buy them, and who knows, it may come to that. But for now they are easily available and when handled correctly they should not cause a problem.

 

[Gerald C Koch]

It's all anecdotal evidence where people find what they're looking for. e.g. I'm a photographer and know a photographer who died of parkinsons. It must have been the chemicals he was using. Fact is nobody really knows.
I'm not suggesting these chemicals aren't bad for us if misused but if treated with common sense and basic safety precautions, then I don't think we should f
ear them. If they were so bad you wouldn't be able to buy them, and who knows, it may come to that. But for now they are easily available and when handled correctly they should not cause a problem.

The same could be said about other suspect chemicals. However studies were done which link them to PD. Unfortunately the days of large photo processors has gone and amateur use may not be enough justification

Many chemicals are not just about impossible to obtain in the EU. For example potassium dichromate.
to warrant study.