The song was written by Ron Angel, who is from I don't know where. But the following extract from Sean Damer's 'Glasgow - Going for a Song' illustrates the song's theme quite well, I think.
[1990:] In the period before the First World War, a great deal of industrial work was highly dangerous. There was no such thing as Health and Safety at Work regulations; the life of a worker was literally cheap. Some of the works must have appeared like Dante's 'Inferno'. [...] The terrible costs of working in this particular inferno [in the mid-19th century] were revealed some thirty years later, in 1889, in a newspaper interview with one of the chemical workers [of Tennant's St Rollox Chemical Works in Glasgow]: "[...] If a man goes to the works young he will be past working before he reaches forty years of age [...]. For instance, you will easily know a chrome-worker from the fact that, as a rule, the bridge of his nose is completely eaten away. [...]" The majority of the chemical workers [in Glasgow] were Irish; they were paid an average of 15s 6d per week, a pitiful wage. [...] The dreadful conditions in these chemical plants were the subject of Keir Hardie's famous attacks on Lord Overtoun in 1899. Overtoun was the proprietor of a large chemical works on the Glasgow-Rutherglen border, and also a noted philanthropist and man of religion. Keir Hardie, in a series of articles in the socialist newspaper 'Labour Leader' - subsequently reprinted as pamphlets - exposed the fearful working conditions in Overtoun's chemical works. He confirmed that the workers rapidly lost the cartilage in their nose working with these noxious chemicals, but also suffered from 'chrome holes' being burnt in their body, and respiratory diseases. Moreover, they worked a twelve-hour day, seven-day week - with no time off for meals, and in foul conditions. (Damer, Glasgow 62f)