Tex. Hum. Res. Code § 122.017

A product manufactured for sale to a political subdivision of this state or an office or department thereof shall be manufactured or produced according to specifications developed by the purchaser. A political subdivision of this state may purchase products or services for its use from private businesses through its authorized purchasing procedures, but may substitute equivalent products or services produced by persons with disabilities under the provisions of this chapter. Nothing in this chapter shall be construed to require a nonprofit agency for persons with disabilities to engage in competitive bidding.