What is the ruling on working in a factory that produces bread and sweets if some of the products contain meat of doubtful origin (possibly pork), bearing in mind that my role is to operate machinery and monitor quality, and is it permissible for me to refuse this job if doing so might expose me to penalties after a previous refusal of another job?

You must inquire about the meat. If it becomes clear that it is pork or meat from an animal not slaughtered according to Islamic law (dhakāh sharʿiyyah), then you must immediately cease working, as it constitutes cooperation in sin. This is unless you are compelled to remain due to an unbearable harm, such as imprisonment or inability to secure necessities, or if you are able to transition away from any work that involves assisting in forbidden acts. We advise you to fear Allah and seek lawful sustenance.