Found my coworker cutting styrofoam with my knife after he heated it up over the burners. Is it ruined?

i work at starbucks, so not really a kitchen, but it's a similar environment. our 'kitchen' is a long narrow corridor with drink stations on both sides, so people are always going back and forth. we use the standard 'behind'/'corner'/etc. callouts most of the time, but for whatever reason we've all adopted the habit of making siren noises when we're walking from one end to the other. i have no idea why, but it does work -- it's a quick way to let everyone know 'hey, i'm going behind all of you, don't move across the walkway until i stop screaming' and it differentiates 'going behind one person and stopping' from 'going behind everyone very fast'.

i'm curious what the normal way to do this would be -- would you just say 'behind' 3x? once, but really loudly? something else? i feel like there's an easy answer that's not as unhinged as our solution (although screaming is more fun i think)