"It is essential that Artist (Spears) not be exposed to any alcohol, drugs or controlled substances ("Prohibited Substances")," the Daily Mail quoted a non-disclosure agreement document obtained by TMZ as saying.
"Accordingly, Contractor agrees to refrain from the distribution, dispensation, solicitation, possession, sale, transfer or use of any Prohibited Substance (collectively, the "Prohibited Activities")," the document said.
It also states that dancers agree to testing without prior notice.
"Contractor agrees that Company shall have the right to require Contractor to undergo medical evaluation, including but not limited to testing at any time or place, with or without notice, to determine whether Contractor is under the influence of or has used or consumed any Prohibited Substance," it added.
If they fail a test, they can be immediately fired.
Dancers also promise not to release any unauthorised photos or videos of Spears.