This is the name for an outbreak of disease that affects a given place in a given time.

An "epidemic" is the correct word.

I think that they key word here is "responsibility" - it's not about what the consumers want , but about what is responsible, that is: what will also be beneficial for others and for the society in general.

The responsible option here would be to b. report the problem to the seller and the manufacturer- this way other people can be warned and not endangered.