The Photographic arts and the science of light and shadows and bio-chemistry of HYPO.
What is Hypo?
Hypo is an abbreviation for Sodium Thiosulphate (Na2O3S2) which is used in the final stage of the developing and processing of Black and White negative film, and photographic printing paper. It is used for arresting the development of the film or print.
As a prefix, hypo- means reduced or retarded. It is a toxic hygroscopic chemical salt and is not well tolerated by the body and also causes yellowing of the nails, hence people who are developing photographic prints are required to use tongs and wear rubber gloves to aviod contact with this solution (refer to the Material Safety Data Sheet – MSDS).
Lo and behold, the other day I saw it as an ingerdient in a package of table-salt, as well as a package of sea-salt, and I was totally perplexed, and hence I am writing this to be enlightened as well as to shed some light on this chemical.
Who has approved the use of sodium Thiosulphate as part of our daily diet, all these years, I only was taught that common salt, or table salt, is Sodium Chloride, but on it’s own was no effective in preventing conditions such as rickets and giotre, and hence iodine was added to the salt to end up with what is known as Iodized Salt.
On this site: http://www.earthclinic.com/remedies/sodium_thiosulfate.html , one of it’s properties being touted is detox, and removal of heavy metals.
This is all so confusing. The medics make us eat apples, take Asprin daily, and have a glass of red wine daily, what next, snake-oil?
Hamilton, Ontario, Canada
Monday 6th October 2014