Hello dan0r,
I can only assume that your clients are also asking you to be certified against a food safety standard. Nowadays there is no supermarket (or supplier of a supermarket that uses your company as packing facility) that agrees to purchase products from you unless you have a GSFI valid certificate or that you pass an audit against their own standard. In all these standards there is a compulsory requirement to have the hair covered, including facial hair. Some standards go even further and ask that also ears have to be covered. Nowadays, you can only supply without being certified if you are the only one producing that product or you offer it at half price than the competition.
I don't know what kind of products are you packing, but did it ever happen in your company that hair was found in the products? I used to do a lot of quality checks and even work in production, so I often found 15-20 cm long hair between strawberries that were freshly picked from the field/glasshouse. Besides the fact that I personally found it disgusting, I was also wondering why aren't the companies that are picking the fruit also obliged to have the hair completely covered. In case hair is found at one of our clients in the UK, automatically our company will be the one suspected of not working according to the rules.
Our risk analyses also describes the risk of contamination with hair from employees. In the end the severity of the risk is low, it is not the same like a piece of glass that can injure someone or an infection with a pathogen, but it is more about losing your reputation at your clients. How can you explain to your clients that hair was found in the product because you are not wearing a hairnet? You are probably receiving visits from the KCB to check the quality of the product. Are they automatically taking a hairnet?