Pyro kit in liquid form

[Deckled Edge]

So far, so good! I've been dunking my hands in HC110 and TMax RS for 6 years without allergic reactions or rashes. My understanding is that while hydroquinone is sensitizing, and can cause serious health consequences to some people, pyrogallol is toxic, and enough exposure causes health consequences to all people. The warning on the HC110 bottle (and any package containing hydroquinone) warns of possible skin reaction. On the other hand everyone who writes about PMK notes that pyrogallic acid is "nasty stuff" and warns about the powder, as well as direct contact with the developer solution.
That said, all the neat stuff in our darkrooms is potentially lethal, if not to us, then to our environment, and should be handled in a responsible manner. We really can't be too careful.
..but I'd hate to go back to gloves! ;-(

 

[Aggie]

This from the British Pharmacuetical codex (recent)

Action and Uses.—Pyrogallic acid is a powerful antiseptic by reason of its affinity for oxygen. Taken internally it exerts a toxic action on the blood, methaemoglobin is formed, passes into the plasma, and leaves the red corpuscles as granular debris; jaundice and acute nephritis may follow, hence the drug is now very rarely given internally. It is used as an antiseptic and mildly irritant ointment in chronic skin diseases such as psoriasis, also to destroy lupus; it is of value as a parasiticide in ringworm. Mixed with four times its weight of starch, the acid is applied as a powder to phagedaenic chancres. It has the disadvantage of staining the skin and hair black, and must be used with caution on account of the danger of absorption. Stains upon the skin may be removed with ammonium persulphate. Pyrogallic acid is an ingredient of hair dyes, usually with silver nitrate; and is largely used as a reducing agent in photography.

 

[Francesco]

Fortunately some of us use tubes for developing sheet film and there is no need to touch the stuff or for that matter work in the dark, hence avoiding any mishaps due to reduced vision. Better safe than sorry. In addition, buying Pyrocat in a liquid form kit, such as that available from Lotus View (I believe they are the only ones that provide this kind of service) , further reduces any chances of whatever miniscule, tiny, microscopic risk there might be of playing around with powdered chemicals.

 

[sanking]

So far, so good! I've been dunking my hands in HC110 and TMax RS for 6 years without allergic reactions or rashes. My understanding is that while hydroquinone is sensitizing, and can cause serious health consequences to some people, pyrogallol is toxic, and enough exposure causes health consequences to all people.

The MSDS safety sheet list hydroquinone as a toxic agent. To quote,

"Probable carcinogen. Toxic. Severe skin irritant. Harmful by inhalation and ingestion. May cause sensitization. Eye and respiratory irritant."

The MSDS sheets indicate that pyrogallol is more of a risk, but the difference is not as great a s some people believe. Chemically the two agents are very similar. People do appear to be more aware of the risk of pyrogallol and pyrocatechin than other reducers, which may be due to the fact that the people who promote developers based on these agents have taken a responsible position and warned of the health risks.

Bear in mind that sensitization to a chemical normally results from long-time use, and once you become sensitized it is for life. I worked for many years on a boat-building project with epoxy and would frequently get it on my hands. I had no problems at all for years and years, but one day after some got on my hands I developed a severe rash, with many visible bumps, on my forehead and fingers. Every since then any contact with epoxy, or sometimes just the smell alone, causes eruptions of the same type and in the same place. I think anyone dunking their hands in developers that contain reducers such as hydroquinone and metol run the same risk of sensitization.

People who insist in not using gloves with tray development should consider switching to one of Patrick Gainer's Vitamin C formulas. My understanding is that ascorbic acid is about as safe a reducer as you can find.

Sandy

 

[sanking]

BTW, I just got word from Dick Sullivan that Bostick and Sullivan will soon begin marketing Pyrocat-HD in a liquid kit. I am confident that B&S will produce a quality product that is fully consistent with my own standards for this developer. And as anyone who has dealt with B&S knows, they are great at providing support for their products.

Sandy King

 

[john_s]

For those who want lots of detail about toxicity of pyro, have a look at the site address below. Note that it's an ingredient in many common hair dyes and occurs in smoked meats (ham etc). One needs to be careful of all chemicals, including those in our food.

One of the things that I like about PMK is that I have to mix stock solution only once every two or three years. Having said that, I'm moving over slowly to pyrocat-HD mainly because of its ability to be used more dilute for minimal agitation, and I like that effect very much.

Dead Link Removed

 

[Aggie]

I posted all about pyro chemis about 3 posts previsous to this. One note. Pyrogallic acid oxidizes rapidly. By the time you have finished using the developer (when parts a and b are mixed together) it is essential inert.