California Code, Education Code - EDC § 49408

For the protection of a pupil's health and welfare, the governing board of a school district may require the parent or legal guardian of a pupil to keep current at the pupil's school of attendance, emergency information including the home address and telephone number, business address and telephone number of the parents or guardian, and the name, address and telephone number of a relative or friend who is authorized to care for the pupil in any emergency situation if the parent or legal guardian cannot be reached.