It depends on your country, but the things that will kill you are usually banned by law.
Some food is associated with cancer. Salted meat for example is not cancerous by itself, but some complex interactions can create, momentarily, some dangerous molecules. Still, salted meat will not kill you by itself, it’s not a poison.
Regularity is what will be damaging. If you drink a lot of alcohol every day, every week, you will usually get cancer. If it’s occasionally, you’ll be fine. I see it as some sort of accumulation versus healing ability of the body. Don’t go over what your body can recover from, and you’ll be fine.
That’s why diversity is the ideal : the more diverse your meals are, the more likely you will have every nutrients you need and the less likely you will accumulate something that would become a problem. No need to be too hard on this either, if you don’t eat the same thing every day you’ll be fine usually.