[throw10920]

> Some employers require sterilisation as part of the job

Such as?

> That does not mean you have to work for them!

If most employers require it, and your school requires it, and airlines require it to fly, then it's effectively mandatory.

[CRConrad]

> If most employers require it, and your school requires it, and airlines require it to fly, then it's effectively mandatory.

Back to the above, working for someone is voluntary. And you certainly don't have to fly anywhere; that's a choice you make. Leaves only school, and that's often more or less voluntary too.

[throw10920]

> working for someone is voluntary

You missed the word "most" in there. If most employers mandate it, it's effectively mandatory. School is also effectively mandatory in this economy. Ergo, my point stands. Don't be intellectually dishonest.