I work in industrial automation, and as part of a project, we had to install a light barrier around a turn table to keep operators safe. Upon noticing that this light barrier was not sufficient (could put my whole hand through it, and touch the turning parts without detection, and the table did not stop moving), I showed my boss.
He said this was fine and that "I had to put my hand in a specific spot for it not to work so there is no issue". He then asked me how I felt about it, and I told him that if I were the operator, I would not be okay with working with this light barrier being the only thing protecting me from getting my hand hit by the turn table.
He then went on to berate me in front of my colleagues about being stubborn and impossible to work with, and that I really should check myself etc., because it's very unprofessional to not be open to criticism or differences in opinion.
I won't be personally liable for injuries caused to operators, but I still do not feel comfortable letting the machine be sold as is. I have filmed my hand going through the light barrier undetected and emailed it to my boss but he seems unswayed.
How can I continue to push for improvements when any difference of opinion with my boss is taken as being stubborn? Any tips for dealing with this type of situation in the future? I'm not particularly concerned with the specifics of this instance (safety laws etc.), mostly how to continue having constructive and professional interactions with this style of management.
Note: I am the only female in the company (of about 100 people so I'm pretty sure there's something fishy going on), and on a work study program. I fear I am not being taken seriously because of my status as a student, and I cannot quit because my contract here is part of getting my diploma.