I hope you're feigning ignorance on that. If we're using an example about allergies and an enclosed situation such as a boat where you can't get off and if you do it affects everyone, some common consideration might be palpable. If you choose to knowingly eat peanuts or trigger someones known allergy after getting on the boat knowing this will be an issue, don't be pissed when the boat has to race for shore because someone went into shock when their throat closed up. With that said, most people with severe allergic reactions like that are quite used to living daily life dealing with those dangers, the only thing they can't prepare for or respond to well is proximity. If someone is sensitively allergic to the smell of peanuts and that triggers their reaction they can't choose to just "avoid it". Particles seem to transfer indefinitely. Things such as sanitizer or other protection are already inbred into their lives but the best prevention if everyone is going on a dive boat is just to not have proximity to it. Even more in this situation, I'm sure people could go without packing a peanut butter sandwich for lunch, they just have to be asked/ warned and agree to being civil.
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