Tex. Education Code § 37.019

(a) This subchapter does not prevent the principal or the principal's designee from ordering the immediate placement of a student in a disciplinary alternative education program if the principal or the principal's designee reasonably believes the student's behavior is so unruly, disruptive, or abusive that it seriously interferes with a teacher's ability to communicate effectively with the students in a class, with the ability of the student's classmates to learn, or with the operation of school or a school-sponsored activity.

(b) This subchapter does not prevent the principal or the principal's designee from ordering the immediate expulsion of a student if the principal or the principal's designee reasonably believes that action is necessary to protect persons or property from imminent harm.

(b-1) The principal or principal's designee may order the emergency placement or expulsion of a student under this section based on a single incident of behavior by the student.

(c) At the time of an emergency placement or expulsion, the student shall be given oral notice of the reason for the action. The reason must be a reason for which placement in a disciplinary alternative education program or expulsion may be made on a nonemergency basis. Within a reasonable time after the emergency placement or expulsion, but not later than the 10th day after the date of the placement or expulsion, the student shall be accorded the appropriate due process as required under Section 37.009. If the student subject to the emergency placement or expulsion is a student with disabilities who receives special education services, the emergency placement or expulsion is subject to federal law and regulations and must be consistent with the consequences that would apply under this subchapter to a student without a disability.

(d) A principal or principal's designee is not liable in civil damages for an emergency placement under this section.