Why is the use of enzymes in biotechnology hazardous to human health??

Answer required my tomorrow promt reply welcome...

Think about what enzymes do. Think of what we are made of.
Here is one example to set the ball rolling.
Imagine you were working with a protease- it breaks down protein- what do we contain a lot of? Enzyme reactions form catalytic activity are usually quiet rare but definitely count as a risk for some enzymes.
Any biological substance can cause an immune response.
I'm sure you can work things out from there.