My worst job ever was the first job I had after I left school. I started work in a local factory in the quality control laboratory. The company had a habit of taking on staff at better terms and conditions than their existing employees. They employed me at a really crappy wage, but at least it was a full-time permanent job, which did not endear me to the lad working there on a Youth Opportunity Scheme. So the pattern of bullying all through school continued at work.
Later on, he was made permanent, then they took on more staff at considerably higher wages than us, and we had to train them to do our jobs.
We regularly used xylene, toluene and carbon tetrachloride. There was no extraction in the lab. We had to get the chemicals from drums kept in the yard, and always got soaked because of the inadequate dispensing equipment. It was my first job after school - I was totally unaware of things like material safety data sheets, control of substances hazardous to health, or risk assessments. Later on in my career, I looked up what I had regularly bathed in and inhaled and became familiar with "harmful", "carcinogenic" and "teratogenic".
The only upside to the job was that I went to college one day a week. As soon as I had a basic qualification, I got a new job, and virtually doubled my salary, and probably my life expectancy too. In the 13 years since I left that company, I have increased my salary by over six times.