"must make sure" or "must ensure" but NOT "must be make sure".
Also, "that nobody is endangered" or "that nobody is put at risk" would be better.

HTH

Steve Martin

A few more possibilities:

Anyone who switches on the plant/unit/equipment must first ensure that no one will/could be endangered.

Anyone switching on the plant/unit/equipment must first make sure that no one will/could be endangered.

Before switching on the plant/unit/equipment, care must be taken that no one could/will be endangered.

Anyone switching on the plant/unit/equipment must first make absolutely sure that nobody will/could be endangered

Care must be taken that no one will/could be endangered before the plant/unit/equipment is switched on.

HTH - Dan

or "must take care" or "must be careful"

has to take care that nobody is endangered.
this is just a literal translation, there is no 'sicherstellen' or
'sich versichern' in the original.

Unlike in German and many other languages, where the tendency is to use third-person pronouns ("one should not...," "one ought to...," "anyone who...."), the tendency in English, especially in the US, is to address the user directly, using the second person pronoun "you" or simply using the imperative or prohibitive form ("make sure to..." or "do not..."). To attenuate any perceived undertones of rudeness, the word "please" is often pasted on the sentence as a balm.

If the intention here is to make the translation sound idiomatic in English, it will be helpful to switch to the second person. Here are a couple of examples:

"Before you switch on the system, please make sure no one is in danger."

"Please make certain that everyone is out of harm’s way before you switch on the system."


The possibilities are not infinite, but you get the idea.

Fuad