(a) Substance abuse may be a serious health condition if the conditions of §§ 825.113 through 825.115 are met. However, FMLA leave may only be taken for treatment for substance abuse by a health care provider or by a provider of health care services on referral by a health care provider. On the other hand, absence because of the employee's use of the substance, rather than for treatment, does not qualify for FMLA leave. (b) Treatment for substance abuse does not prevent an employer from taking employment