We have vacuum breakers but my dad will inevitably remove it because he can’t stand that humming sound. He also insists on leaving the hose bib/valve at all times, even when he’s not using it.
I don’t want my parents to accidentally poison themselves or us when we visit.
I don’t think they will poison themselves. I had to look up what a vacuum breaker is, never seen one in the uk, and not seen reports of anyone being poisoned due to not having one. Check valves are sometimes used (for water heaters for example) but those are silent.
My dad uses those insecticide or fertilizer things that hook up to a hose. I’m just worried about backflow into our pipes from it
I hate that hum too. I don’t suppose you found any solution?
That sounds like a bad idea to me. But a simple check valve should keep them safe i think