This is the story of how the application of luminescence on the first military dials in the early 900s turned out to be a serious health problem and the measures that today are summarized in the inscription T-swiss <25 were then adopted.
Let's jump back in time ...
In the late 1800s, exactly in 1898, radium was discovered and in 1902 isolated as a pure element. It was introduced in the most common uses as a revolutionary tooth whitening element, miraculous for the treatment of tumors, in make-up and beauty products .. its unique property was its luminescence and the warmth of its salts.
Marie and Pierre Curie, the scientists who discovered Radio in 1898
During the First World War the military complained about the poor impact resistance of their watches and how they could not read the time in the dark during the nights in the trenches.
For this reason the manufacturers of dials began to use radium mixed with glue and a small quantity of zinc sulphide thus obtaining a luminescent paint to be applied to the hands and indexes. So it was that the first watches with "luminous" dials and hands were born that helped the military in the endless nights in the trenches to consult their measuring instruments but without being noticed by the enemy.
Example of a luminescent dial
The quantity of radioactive material present on the dials was not such as to damage the wearer, but on the contrary, it was the beginning of the end for those who painted the dials.
In 1917 thousands of women were hired in the United States and Canada to apply radio-based luminescent paint to the dials;
the danger of radium was not known, on the contrary, it was considered a miraculous element, given its wide use in the main daily uses and in medicine.
A bottle of RADITHOR, a medicine used in the 20s as a cure for various diseases.
The girls were asked by the production supervisors to thin the tip of the brushes during their use, to achieve maximum precision in outlining the numbers on the dials; the brush was inserted in the mouth and turned while pulling it between the lips to ensure that the bristles were always compact. This caused the luminous substance to come into contact with the lips and tongue and possibly swallowed.
The "Radium Girls" at work
The serious thing is that it was never questioned whether this was safe for painters, regardless of whether scientists and superiors used safety measures: lead shields, special gloves to avoid exposure to themselves. The scientists and owners of the firm were aware of the potential risks.
Sometimes the girls used to paint their nails and lips with luminescent paste, their dancing evenings in the village with their boyfriends took on a whole other "light", unaware of what would have happened in a few years.
This was how they began to suffer from radiation sickness. The most common symptom of the disease, due to their work in the factories, was necrosis and fracture of the jaw. The teeth were starting to fall, there was severe swelling in the jaw, severe anguish and weakness. Dentists and doctors in Orange, New Jersey began to notice an increase in the amount of disease and damage found in the jaws of local youth and women. The bond that united them soon became evident: everyone had worked at the Radium factory in the United States.
And Rolex? .. how did he behave about it? ..
Rolex watches from the 50s still used radium for luminescence. The luminescence models were mainly Submariner, Turn-O-Graph, Explorer and GMT Master.
Big Crown Submariner on the radio, photo rolexpassionmarket.com
The Atomic Energy Commission of the late 50s set limits in terms of radioactivity, also forcing watch manufacturers to comply with the new laws.
Rolex continued to use radium, but did so by applying a less aggressive paint, thereby lowering the radioactive content of its products.
To indicate this activity of reduction of the Radio, the models of the crowned house, had an indication on the dial, a dot under the six o'clock index, the collectors defined these references "ESCALMATION POINT".
Gilt ROLEX Submariner Ref. 5512 Photo rolexpassionmarket.com
In 1962 there was a new lowering of these thresholds, the control bodies set the presence value of the radioactive materials to a maximum of 25 mCi (millicuries).
From 1963 to 1964, very rare dials will be produced in the Rolex house, with a small line under the inscription, this indicated the new material used by the manufacturer to make the luminescent dials, TRIZIO, a hydrogen isotope , less bright and much less radioactive than Radio.
Rolex Submariner 5513 from 1963 called "UNDERLINE"
From 1964 to 1967 the inscription appears on Rolex watches Swiss - T <25, which unequivocally refers to the presence of tritium with a level of radioactivity below the 25 mCi required by law.
Rolex Submariner 5513 from 1964 with SWISS writing - T <25
In 1993 an aluminate and strontium pigment was invented, patented in 1995 under the name of Luminova. This made it possible to obtain non-radioactive luminescence. Rolex began to use this new component from 1998, so only the word Swiss appeared on the dials, then replaced with Swiss Made from 2000, given the use of Super Luminova, a new compound more powerful than traditional Luminova.
From 2009 Rolex began to use Chromalight, the material of his invention, a distinctive feature of the color of luminescence, blue.
Check out the graphics inspired by this article! EXCLAMATION POINT
See you soon!
MAX by INCASODIVINTAGE