I won’t forget and won’t let you forget, either: There are no toxic plastics, but people want to think so because they are changeable/moldable and “chemical.” The science of chemistry, like all science, challenges belief in the impossible, which we all need to some degree. So we are scared of this “unknown” and don’t really want to know it well, lest we see the nontoxic truth.
Now to maintenance of extrusion lines. Some of you are old enough to remember Bert Lance, Jimmy Carter’s banker friend and budget director, who popularized the expression, “if it ain’t broke, don’t fix it.” The folksy, ungrammatical structure appealed to the anti-intellectual sentiment popular at the time. It may be sound advice in banking and politics, but not in a factory, where staying alive means doing things to avoid both kinds of broke.