Under section 14(c) of the Fair Wage Act, it is legal to pay disabled workers less than minimum wage - for example, Goodwill pays disabled workers just 22 cents/hr. There is no requirement to allow breaks for disabled workers.
Though there is now an executive order requiring contractors to be paid at least $10.10/hr regardless of disability status, non-federal contractors are still subject to the demeaning practice of being scrutinized and having their wages adjusted based on subjective measurements. The work of disabled people should not be considered fundamentally different from the work of the fully-abled, and the use of separate minimum wages creates a high rate of poverty for disabled folks.
For more information: http://www.dol.gov/whd/specialemployment/workers_with_disabilities.htm