The answer is that it depends on the nature of your job: you say, for example, that it is "safety related." If suffering a seizure at work would potentially put you or other people at risk, your employer may be entitled to terminate you for being prone to such seizures, and such action would not be considered illegal discrimination against the disabled. For example: someone who might have seizures clearly could legally be terminated from, or not be hired for, a job as an operating engineer, a truck driver, a pilot, or a heavy equipment operator. If you believe that your condition could be accomodated at work and does not pose safety hazards, then it would be worth consulting with an employment law attorney to see if you do in fact have a claim for illegal disability-based discrimination.