Hydroquinone is a carcinogenic skin whitener???

[Terrance Hounsell]

FYI please find the CBC Story at the following link:

http://www.cbc.ca/canada/ottawa/story/2007/10/29/ot-skin-whitening-071029.html

Which includes this quote:

In 2006, the U.S. Food and Drug Administration proposed a ban on over-the-counter sales of skin-lightening products, citing potential health risks of the common ingredient hydroquinone.

Hydroquinone is a possible carcinogen and has been linked with disfiguring condition called ochronosis that causes darkening and thickening of the skin, along with raised bumps and greyish-brown spots.

???? Does anyone know if this applies to developers ????

 

[Ian Grant]

Thats very old news and has no bearing on photographic uses

Ian

 

[gainer]

A skin lightener that causes darkening of the skin would be the sort of thing that some bureaucrat might try to ban. It has, of course many uses but so does sodium hydroxide.

My first contact with hydroquinone was about 68 years ago. So far, my most serious ailment has been old age, followed by conkus of the bonkus: everything I eat turns to excrement and comes out my anus.

 

[MikeSeb]

God, the internet. The Cloaca Maxima of news, gossip, and panic.

 

[Tom Hoskinson]

FYI please find the CBC Story at the following link:

http://www.cbc.ca/canada/ottawa/story/2007/10/29/ot-skin-whitening-071029.html

Which includes this quote:

In 2006, the U.S. Food and Drug Administration proposed a ban on over-the-counter sales of skin-lightening products, citing potential health risks of the common ingredient hydroquinone.

Hydroquinone is a possible carcinogen and has been linked with disfiguring condition called ochronosis that causes darkening and thickening of the skin, along with raised bumps and greyish-brown spots.

???? Does anyone know if this applies to developers ????

It does not apply.

You should always practice chemical safety when working with any chemical reagent. (This includes water).

For scientific Material Safety Data information based on actual data (instead of news media hysteria):

Here is the URL for the JT Baker Hydroquinone MSDS:

https://www2.carolina.com/webapp/wcs/stores/servlet/msds/868230.pdf

CARCINOGENICITY: NTP: NO IARC: NO Z LIST: NO OSHA REG: NO

CARCINOGENICITY NONE IDENTIFIED.

REPRODUCTIVE EFFECTS, NONE IDENTIFIED.

EFFECTS OF OVEREXPOSURE
INHALATION: HEADACHE, COUGHING, DIZZINESS, DIFFICULT BREATHING
SKIN CONTACT: IRRITATION
EYE CONTACT: IRRITATION
SKIN ABSORPTION: NONE IDENTIFIED.

 

[Photo Engineer]

I would add to Tom's list, the potential for kidney damage if injested, but that applies to most foreign chemicals.

BTW, Quinoline is used in 'man tan' and similar chemical tanning agents. It is quite toxic IIRC, but is still used as so many want a quick chemical tan.

PE

 

[maxbloom]

Or with a little organic chemistry you could turn it into a quinolone and take it when you get sick.

 

[Photo Engineer]

Max;

Are you thinking of quinine? That is entirely unrelated to this.

Also, thinking it over, I think it is a quinoline derivative rather than the parent quinoline that is used in Man Tan.

PE

 

[maxbloom]

No, I was thinking quinoline, which is basically a benzene and a pyridine stuck together, as I'm sure you know. And then quinolones (parent group is basically nalidixic acid), which looks like two pyridines stuck together, with one of them pretty heavily oxidized and other one methylated.

see http://en.wikipedia.org/wiki/Fluoroquinolone

 

[Michel Hardy-Vallée]

People tend to forget it, but hyrdoquinone is in the same class of toxic chemicals as pyro. Don't sniff that powder, it won't do you good.

 

[Photo Engineer]

Michel;

Pyro is by far more toxic than HQ. Look at Anchell and Troop for their comment.

They say that pyro and its derivatives are among the most toxic chemicals used in the darkroom.

PE

 

[skahde]

They say that pyro and its derivatives are among the most toxic chemicals used in the darkroom.

Just one question: What source or citation do Anchell and Troop give for their statement? What source or citation one could crosscheck do they give anywhere anyway?

best

Stefan

 

[john_s]

Pyrogallol was used as to treat a skin disorder here (Australia) for many years. One patient did succumb to cancer after using it thickly on the whole back of his hands every day for something like 20 years (iirc). It's not used anymore for this purpose. Reasonable care in the darkroom makes it not a concern.

Hydroquinone is reputed to be bad in effluent because it affects marine life.

 

[Ian Grant]

Stefan, all commercial chemicals have MSDS (US) or COHSS (EU) data sheets and even before these two systems data was published about the toxicity of these chemicals.

The toxicity of various photographic chemicals has been known about for a considerable period of time, and as such authors like Anchell & Troop would have access to a wide variety of sources. However they were not publishing a scientific or academic paper so had no call to cite sources.

Ian

 

[skahde]

[...] as such authors like Anchell & Troop would have access to a wide variety of sources.

Question is why didn't they check them? Hydroquionone and Pyrogallol have more or less identical toxicity and cancerogenicity if you have a look at the MSDS.

However they were not publishing a scientific or academic paper so had no call to cite sources.

They certainly were not obligated to give a proof but in this case they were not able to give one in the first place as their statment is plain wrong. There is quite a number of rather bold statements in the photographic literature where there is no kind of proof given but which are in contradiction to well documented work others did. My personal conclusion is to rather ask for proof than taking for granted that some highly regarded source may not give false information in one place or another (and they inevitably do!).

At the end of the day it is our negatives, prints or even health which may take harm or your time and money wasted and in such a situation it's IMHO not clever to just rely on someone elses word.

best

Stefan

 

[jim appleyard]

Skin whitener? Michael Jackson?

 

[Ian Grant]

Stefan, as someone who has worked with chemicals almost all my working life I don't take everything in MSDS/COHSS data as gospel.

It is normal lab practice to treat all chemicals with respect, and a few with extreme care, in my case that was cyanides and Hydrofluoric acid.

Its up to you to read for yourself and decide how you handle chemicals. Photographers found from experience that Pyrogallol was more toxic than Hydroquinone not through a few experiments with lab rats.

What you are calling rash statements are just accumulated knowledge built up over a number of years. But you would find the same information coming from very different origins. LP Clerc's data came predominantly from Europe and French photographic companies, while Kodak's came from the US and the UK.

We don't need to read the original papers and sources because history has informed us how to safely use these chemicals in our photographic practice.

Ian

 

[skahde]

Stefan, as someone who has worked with chemicals almost all my working life I don't take everything in MSDS/COHSS data as gospel.

At some point writing MSDS was part of my job and I therefore know there limitations very well.

Photographers found from experience that Pyrogallol was more toxic than Hydroquinone not through a few experiments with lab rats.

But what kind of experience? Described where? Observed and confirmed by who? As long as there is no kind of evidence given I'd rather trust the rats.

What you are calling rash statements are just accumulated knowledge built up over a number of years.

Have a look at eg. Richard Henry "Controls in Black and White Photographie" and see how much of that "accumulated knowledge" turns out to be well ripened myth when really put to the test.

We don't need to read the original papers and sources because history has informed us how to safely use these chemicals in our photographic practice.

Ian

No, I don't think knowledge does accumulate. In my view it is lost over time once it has been established. What you describe is a situation where nobody refers to the original papers anymore but information taken from them goes from ear to mouth into publications, out again taking another round, loosing shape and contents to a degree where the original statment is hard to be recognised or lost alltogether.
As a result, there is lots of "wisdom" around which has little to do with what was meant but lots of procedures are in use which obviously work but there is little in-depth knowledge around why and in some cases why not. That is where we are: Photography is as much science as it is craft.

But coming from the craft-side one shouldn't pretend to do any kind of science or make statments beyond that somethings "works" within the craft. There are clear rules how to part assumption and myth from knowledge (as limited as it might be) build up over times much longer than photography exists. Not sticking to them is a weekness often accepted by authors for a reason: Emperors new cloth.

best

Stefan

 

[Willie Jan]

If you know how many photographic used chemicals are in our food, you will stop eating.

 

[Ian Grant]

Stefan, a simple Google search brings up plenty of material on the relative toxicity of Hydroquinone and Pyrogallol.

One line in "Environmental Goitrogenesis" - By Eduardo Gaitan states "Hydroquinone and Pyrogallol may cause discoloration of the skin, and Pyrogallol even death after topical application. This is a scientific publication with plenty of references to other sources.

Another states "PYROGALLIC ACID (pyrogallol, 1,2,3-trihydroxybenzene). Pyrogallol is highly toxic by every route of exposure and can also readily be absorbed through the skin. It then goes on to list the problems.

There is plenty of documented evidence again in scientific publication, looking into the causes of sickness in darkroom workers, and the word Pyrogallol features in them all as being by far the most toxic of the developing agents.

So Anchell & Troop aren't printing myths, it's one of the reasons why photographers and more particularly manufacturers like Kodak, Ilford & Agfa moved away from using Pyro based developers. The smaller scale use is far less of a problem, in comparison top commercial darkroom & their workers exposed to Pyrogallol throughout the whole of each working day a century ago.

If you choose to ignore scientific facts, published widely and freely available that's up to you. The evidence is there if you look for it.

Ian

 

[srs5694]

Taking another course from the original question, if the toxicity of hydroquinone is a concern, you might want to investigate using ascorbic acid, or one of its variants, instead. You can usually achieve similar results with ascorbic acid, although you'll need to adjust quantities of various ingredients, particularly if you use ascorbic acid rather than sodium ascorbate. (Note that "similar" doesn't mean "identical;" if you're very picky about your developers you may find the subtle differences unacceptable.) APUG members Ryuji Suzuki and Pat Gainer have both published several popular formulas that use ascorbic acid, and a few commercial products use it, too (Kodak XTOL, Agfa Neutol Plus, and Silvergrain Tektol spring to mind).

 

[Photo Engineer]

All of this furor claiming that A&T gave no reference.

Well, if you read A&T, you would find that they DID give a reference. It is a citation by Gordon Hutchings who said that "They may be the most toxic chemicals in the darkroom". I would personally amend that to say "second to selenium".

None of the above are severly toxic if, as Ian has pointed out, you observe safe handling procedures in mixing, use and disposal.

PE

 

[Photo Engineer]

In extensive tests by Kodak, HQ and Metol and several color developing agents (CD-3, CD-4 and CD-6) were found to be low in toxicity as they are not absorbed through the skin to any great extent. This reduces toxic reactions from contact.

Other developing agents can be readily absorbed through the skin.

All of them are toxic to some degree or another if you injest them.

PE

 

[skahde]

Stefan, a simple Google search brings up plenty of material on the relative toxicity of Hydroquinone and Pyrogallol.

Thank you for taking the time and doing a search. I couldn't agree more that Hydroquinone as well as pyrogallol should both be treated with care and will both cause serious problems if not used in line with appropriate caution.

My point is the difference between pyro and hydroquinone and as far as I can your search still didn't turn up anything demostrating any large difference in toxicity or cancerogenicity.

Another states "PYROGALLIC ACID (pyrogallol, 1,2,3-trihydroxybenzene). Pyrogallol is highly toxic by every route of exposure and can also readily be absorbed through the skin. It then goes on to list the problems.

If you extend your search a bit you will find that hydroquinone is also readily absorbed through the skin. Maybe to a lower rate, I don't know. But I would check if wanted to know. Or if I would care if pyro is an extraordinary risk compared to other developing agents which are in regular use or if wanted to write down such a statement in a book.

There is plenty of documented evidence again in scientific publication, looking into the causes of sickness in darkroom workers, and the word Pyrogallol features in them all as being by far the most toxic of the developing agents.

Sounds like interesting reading. I'm sure you could reference it. And you take it for granted that Hydroquinone is much better?

So Anchell & Troop aren't printing myths, it's one of the reasons why photographers and more particularly manufacturers like Kodak, Ilford & Agfa moved away from using Pyro based developers.

They moved away from pyro because hydroquinone was more convenient to use, gave better, more consistent results and was also cheaper.

Do a search for the risks connected with the regular exposition to hydroquinone and it will be equally long showing a different but in no way better picture.

If you check the facts and don't rely on 3rd, 4th, 5th generation literature there is little difference between pyro and hydroquinone with respect to the safety you should apply when using them and the risk connected with their use.

best

Stefan

 

[Photo Engineer]

The LD50 of Pyrogallol is very low. Due to a lack of volunteers (Gordon's words), there is no exact human data but he does publish an estimated LD50 for humans from known cases of lethal poisoning by pyro. It is apparently very low when compared to HQ.

PE