Hydroquinone toxic in Canada?
Last night I received information that Environment Canada is looking at the regulation of Hydroquinone as a toxic substance. They are asking for input from "Industry and other interested stakeholders". There is a complete outline of the concerns and proposals in the fallowing links.
Last edited by m. dowdall; 01-31-2008 at 03:06 PM. Click to view previous post history.
Whoa nellie - I'm a worried now
While I mix my own chems, and likely have a kg or so of HQ at home, I would not dream of rubbing it on my skin. In its dry form it is an extremely fimely divided jumble of needle like strands. When I weigh it I have the full face mask filter on, and the scale is placed in front of the exhaust intake at the end of my sink. I put a board over the end of the sink where the fixer tray usually lives.
I suppose I am exposed to it when I pull paper from the developer tray when the tongs just wont grab it properly.
The most HQ that I use at a time is when I am using d-85 like high contrast lith developers. - they swallow a LOT of HQ in comparison to traditional grey scale developer. In that case I keep my fingers out of the tray due to the caustic alkali though.
If we are in a situation of the HQ being overly regulated, then we perhaps we will be reduced to smuggling in a few grams of phenidone from some third world producer, and mixing it with Vitamin C from the health food store, and Borax from the laundry detergent aisle at the grocery store.
Thats what I am going to do to demonstrate traditional photography to my son's Boy Scout troop next month. I complied all the MSDS data sheets, and emailed them to the troop commissioner. They are more worried with the splash hazard from the Ilford rapid fixer. The developer, when you cook it up with mostly things that they already can identify with from having it around the house, didn't worry them at all, and the phenidone is needed in such vanishingly small amounts, that it is not percieved as a risk.
I will be shooting portraits of the kids with my 4x5 loaded with old ortho lith film. I have. It takes a full dump of 2400w/s into 2 heads at 6' to get the needed amount of light, for this equivalent to 3asa film. The kids will then process their own piece of film in a tray on the blacked out and lit by red safelight stage at the end of the gym where they meet.
Almost every conventional paper and film developer has some Hydroquinone in it. It would be a very sad fact if those developers were prohibited. These include developers such as D-76, ID-11, Dektol, etc. Hydroquinone is one of the absolutely basic building blocks of modern developer design. I have been mixing (from powder) and using developers with Hydroquinone for over 40 years, and I have yet to grow another arm, or have any appendage of mine fall off.
Noticed this comment at one of the links:
Originally Posted by m. dowdall
"Canadians may also be exposed to hydroquinone through handling photo developer chemicals for processing black-and-white film. Since the increased popularity of digital photography is rapidly replacing film photography, this type of exposure would be expected to continually decrease over time."
HQ does seem to have some toxicity but reading the links they confirm that the route of entry to the human body for photographic use is via the skin. Conclusion: don't put your fingers in developer, or wear gloves.
If you plan on handling the dry powder you are probably going to breath in significant amounts unless you are using a facility with more advanced ventilation/extraction than is normally used for a darkroom.
Also, don't breathe tobacco smoke and wood smoke. Catechol and Hydroquinone are present in both.
Originally Posted by DaveOttawa
Human urine is also a Source of Catechol and Hydroquinone.
Everything is analog - even digital :D
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Good Afternoon - Thanks to Mike Dowdall for posting this to this group.
Part of ensuring that the message of the "hobbyist" community is heard is to ensure that the Government receives as many submissions as possible. Submissions on both the Risk Assessment and the Risk Management document can be submitted electronically until March 18th, 2008. Anyone can submit a comment- even if they are not from Canada.
I have reattached links to both documents -
There are numerous areas where your expertise can be useful - but the most important aspect is how the regulation of HQ will affect you and your hobby. It is also important to note that the the use of HQ as part of the developping process misunderstands how unlikely it is to come into contact with Human skin for a period of time that would lead to skin absorption.
I thank you in advance for all of your help on this issue!
My offical note to EC
From a photography web site I note that your organisation is reviewing the classification for Hydroquinone.
(ie as found in documents Risk Management Scope for 1,4-Benzenediol (Hydroquinone)Chemical Abstract Service (CAS)Registry Number:123-31-9 )
The exposure limits for dermal contact to me seemed to presume that a photo hobbyist would immerse their hands in a solution containing HQ. This is not a very standard practice.
The concentration of the HQ in such solutions also seems to be mis-represented.
HQ is frequently one of the developing agents of choice found in film developers, and in print developers.
Most photographers do not allow their skin in contact with film developer.
While it is possible to develop sheet film (4x5”, 8x10” etc.) in a tray, and handle it with your fingers, it is a more common practice to develop sheet film in a deep tank and handle the film via hangers the film is suspended from.
The much more common roll film formats (35mm, 120 format, etc) is commonly processed by rolling the film on a reel, placing the reel in a light tight trapped tank, and pouring the solutions in and out while the lights are on. Occasionally some drops of solution may contact the skin while solutions are being poured in and out of the tank. .
B&W Print developer is more common form in which one might contact HQ. A typical print developer stock solution contains about 12g of HQ, and it is typically diluted at a rate of 1:1 to 1:3 with water. The prints are typically moved from tray to tray by using tongs. When multiple prints are stuck together in a tray, tongs may not have the grip to separate them, and an un-gloved pair of fingers may be needed to separate the sheets.
The reason most photographers keep clear of the wet developer solutions is that they are typically rather alkaline, and therefore a skin irritant irrespective of the presence of any developing agents.
The developer solution with the highest concentration of HQ that I use uses 22g/L, and is used to process lithographic films. It is also quite alkaline, achieved by the use of sodium hydroxide as the alkaline agent. It is not what one wishes to soak you hands in, as though you are being intoned to do so by ‘Madge the manicurist’.
For an insight into hydroquinone as present in photographic developer solutions, I would recommend ‘the darkroom cookbook’ by anschell and troop.
Please advise me of any additional information that you may require. I would be interested in getting notices of how the review of this chemical is progressing.
I think you ought to have specified that that is 12g per liter of stock solution, so that the final concentration in the user solution is 3 to 6g per liter.
Originally Posted by Mike Wilde
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Good Ol' Canada: start worrying when the problem is vanishing...
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"One of the most singular characters of the hyposulphites, is the property their solutions possess of dissolving muriate of silver and retaining it in considerable quantity in permanent solution" — Sir John Frederick William Herschel, "On the Hyposulphurous Acid and its Compounds." The Edinburgh Philosophical Journal
, Vol. 1 (8 Jan. 1819): 8-29. p. 11
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Originally Posted by mhv