Before 1897, matchboxes could be deadly because of the white phosphorus used in the matches. This substance could cause fatal poisoning if swallowed, and such ingestions—whether by accident or on purpose—were not rare. Many people are unaware that the simple act of lighting a match, especially the first one of October or when starting a fire, once carried hidden dangers. Workers in match factories faced severe health risks, including a condition known as "phossy jaw," or phosphorus necrosis of the jaw. This disease, caused by prolonged exposure to white phosphorus vapors, began with intense pain and abscesses in the jaw and eventually led to the death of the bone tissue. Affected areas would glow a greenish white in the dimly lit workshops. The only treatment was the surgical removal of the jaw, and without this, death was inevitable. A photograph exists of a 28-year-old worker who underwent this surgery. White phosphorus was first used in matches in 1831 by the French chemist Charles Sauria. The first medical report describing "phossy jaw" was published in 1845 by a doctor named Lorinser in Vienna. In France, a law passed on August 2, 1872, created a state monopoly on matches, leading to the closure of private factories and reserving match production and sales to the government. Finland had already banned white phosphorus in 1872, and Denmark followed in 1874. France eventually banned it, with some sources placing the ban in 1897 and others in 1898. The push for this ban in the 1890s was largely driven by workers, with women playing a key role. The movement spanned over fifty years of protests and campaigns. In London, the 1888 strike by the "matchgirls" of Bryant & May brought attention to the dangerous working conditions and the health risks of white phosphorus. In 1891, a new factory funded by the Salvation Army opened and used red phosphorus, a safer alternative. However, the United Kingdom did not pass a law banning white phosphorus until 1908, with the ban becoming effective after December 31, 1910. Initially, these safer matches were three times more expensive than those containing white phosphorus. By the end of the 1890s, two French chemists, Henri Sévène and Émile David Cahen, showed that phosphorus sesquisulfide could be used to make a non-toxic and non-explosive "strike-anywhere" match. The year of their demonstration varies, with some sources citing 1898 and others 1899. Their work earned them a Montyon prize, which recognized contributions to improving unhealthy working conditions. In 1902, the Aubervilliers factory was rebuilt to use their continuous production machines. The Berne Convention, signed on September 26, 1906, banned white phosphorus in matches and prohibited the import and sale of matches containing it. This was the first international effort to ban an industrial product, though it did not take effect until January 1, 1912. The convention remains in force in 48 countries. In 1925, Edward Phelan, who later became the director general of the International Labour Organization, suggested that the creation of the ILO could be traced back to this 1906 convention.