Dear wristwatch friends, welcome back to IWS for another watchmaking tale. This is a story of courage and injustice, set in the early 20th century, during the First Great World War, when a group of young women became unintentional symbols of intrepidity and resistance in the face of an abuse of power that over time proved deadly.

These women went down in history as “The Radium Girls,” a name that today is associated with one of the most emblematic tragedies of work-related hazards and struggles for workers’ rights. But before we go to find out who these girls were and what they went through, we must remember that at one time, watches and various measuring instruments, were coated with a Radium substance, the antagonist of this sad story.

Why were the clocks covered with radium?

Radium was discovered in 1898 by Marie and Pierre Curie, two French scientists who played a key role in the study of radioactivity. The element was isolated from pitchblende (more commonly called Uraninite), a particularly uranium-rich mineral that the Curies were studying for its high radiation output. After a lengthy refining process, they were able to isolate a small amount of a new element, which they called “radium” because of its ability to emit radiation.

Radium is extremely radioactive; it is one of the elements that emits alpha, beta and gamma radiation, a process that involves the transformation of one element into another. Its radioactivity is so strong that it can cause luminescence, that is, glow in the dark, a property that was exploited in the early decades of the 20th century for the production of luminescent paints, used precisely to coat the spheres and markers of watches.

It was used for a wide range of purposes, from medicine to consumer products since it was thought to have beneficial properties. One of the most popular applications, starting in 1917, was the use of radium in the production of luminescent paints for that matter.

For this, dial makers began to use radium mixed with glue and a small amount of zinc sulfide, resulting in a luminescent paint to be applied to the hands and markers of watches.

Among the best-known companies was the United States Radium Corporation, based in Orange, New Jersey, one of many factories that employed women to apply luminescent paint containing radium to watches and other instruments.

Who were the “Radium Girls”

With the outbreak of World War I, the demand for instruments with luminous dials grew dramatically. The work of painting these dials required precision and delicacy, qualities that were attributed to the often very young women who were hired in the factories.

Women who worked in radium factories were encouraged to use a technique known as “lip, dip, paint” (“lick, dip, paint”). To ensure that the brushes were always sharp, they were told to wet them with their mouths, then dip them in radium paint and finally apply them to clock faces.

This process was repeated hundreds of times a day. No one, or at least, so the workers were told, suspected that this practice could be harmful. On the contrary, the company and many scientific experts of the time reassured the female workers that radium was a safe substance, even beneficial to health. In fact, it was believed that small amounts of radiation could be therapeutic.

Young female workers were fascinated by the luminescence of the paint, so much so that they often enjoyed painting their fingernails, teeth and even their faces, unaware that they were absorbing a lethal substance. Not only was the radioactive paint handled carelessly, but they were not given adequate protection to avoid prolonged contact with radium.

The deadly consequences of radium on female workers

After a few years of daily exposure to radium, unfortunately many of the girls began to experience alarming symptoms such as glowing skin in the dark. The disease that afflicted them was later identified as “radial necrosis” or “radium jaw,” a condition caused by the accumulation of radiation in the body. Radium, in fact, behaved similarly to calcium and was deposited in the bones, where it slowly emitted destructive radiation.

Dear friends, I will spare you from the details of the terrifying consequences and situations the girls were subjected to, leaving you to imagine how much they suffered.

In short, despite clear signs of widespread illness among female workers, companies and doctors hired by the companies tried to downplay the seriousness of the situation. In many cases, they tried to blame the illnesses on natural or personal causes of the female workers, such as poor hygiene or venereal diseases. The situation became increasingly tragic when some of the girls began to die from complications resulting from radium exposure.

The legal battle of the Radio Girls

Despite their physical suffering, many of the radium girls did not give up. Five of them, including the famous Catherine Wolfe Donohue, decided to file a lawsuit against the United States Radium Corporation in 1927. This was a courageous step, especially considering that, at the time, labor law was still rudimentary and protections for workers were limited.

In 1928, the women won their case and were awarded financial compensation and recognition for the harm they had suffered. More importantly, their victory paved the way for a series of significant reforms in workers’ rights, including improved safety regulations and the introduction of stricter controls on the use of radioactive materials.

New materials for watch luminescence

Today, to achieve luminescence in watches, safe and technologically advanced materials are used, which have replaced the dangerous radium used in the past. After watch companies abandoned the dangerous radium, they switched to the use of Tritium.

Tritium is a radioactive isotope of hydrogen used in sealed capsules to provide autonomous luminescence (without needing sunlight to shine) over the long term. Its radioactivity provides an autonomous luminescence that can last up to 10-25 years. It could be distinguished by the inscription at the bottom of the dial at six o’clock“SWISS MADE T,” where the “T” stands for Tritium.

Another material used in the past, was Promethium-147; a radioactive element that was used in some watches as a luminescent material and to this day it is extremely rare to find watches using it. However, because of its radioactivity and potential health risks, it has been almost completely replaced by safer materials such as LumiNova and Super-Luminova.

Super-LumiNova precisely, is currently the most widely used luminescent material in the watch industry. It is a compound based on phosphoric aluminum oxide (strontium aluminate) and contains no radioactive materials, making it safe for those who handle it and for daily use on the wrist.

It absorbs light energy (both natural and artificial) and releases it in the form of green, blue or white visible light in the dark.

Conclusions

Not only did the radium girls pay a huge price in terms of health and broken lives, they also left an important legacy. Their legal struggles were among the first to establish corporate responsibility for employee safety and were a precedent for many other workers’ rights movements in the United States and around the world.

Today, they are remembered as pioneers of labor justice, victims of tragic scientific and industrial ignorance, but also as heroines who did not hesitate to fight against powerful corporations to claim their dignity and rights. Their story serves to remind us of the importance of workplace safety and the inestimable value of human life in the face of any technological advance.

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