it's an interesting question...
If you talk to disabled people, or even representative bodies, they tend to be reasonably 'resigned' to the fact that in going about their business they might be at slightly more risk from fire than the rest of the population. It's one aspect of living with their condition and the price of maintaining an active life. It often applies even when at home. However, that's not the whole story.
What should also be considered is the 'societal concern' aspect of fire risk. It's most relevant where companies find themselves offering access to their services or premises to the disabled without necessarily being able to completely describe how they would deal with their evacuation in a fire emergency. Society tends to regard firms as having a greater level of responsibility for the safety of particularly vulnerable persons (the elderly, small children, disabled people etc), so even though the individuals involved consider the extra risk acceptable, and the company might, 'society' may not, if there were an incident and the vulnerable people were killed or injured. These companies have to ask themselves "What would the newspaper headlines say..."? Even if it isn't a legislative risk, it might be a reputational one...