it can be dangerous in many different ways depending upon ones mental disorder...example if someone with schizophrenia happens to be at work doing their designing of software and have one of their delusional hallucinations that their software they are designing tells them that the others that work there are out to get them, are going to kill them, that person with schizophrenia may think this means to harm\kill others on the job.

another example if you are keeping up with the news you will see many instances where people in many walks of life and jobs with mental disorders have committed crimes and other avenues of harms to one self or others because their mental disorder affected how they did their job, even if the job is something mundane or simple or extremely complicated there are many different ways mental disorders can affect that persons job to the point where that person while doing their job becomes a danger to their self and others.

the job doesnt have to be like working heavey machinery, or driving (all those warning sticker type things) for that person with a mental disorder to have a mental problem that results in that person having a critical/dangerous problem.

my point its not exactly about the job, its about the person and how their mental disorder symptoms affect them. thats why treatment providers, work places, department of motor vehicles and other public avenues sometimes need to "restrict\limit" what a person with the mental disorder does and places like social security/work places have to determine/ decide how the mental disorder "restricts\limits" a mental disordered persons abilities. in other words whether this person is disabled or not to that state and countries definition of being disabled and unable to work and able to receive the funding called disability, SSI, SSDI which ever the person is applying for.