Neither the provisions of this chapter nor rules of the board adopted thereunder shall apply to volunteer fire departments which are not regularly engaged in the provision of emergency medical care and which offer only Basic Life Support response and do not transport. Volunteer fire departments which regularly provide emergency medical care shall be subject to this chapter, except when entitled to an exemption pursuant to Section 22-18-2. Provided, however, that this chapter and regulations adopted thereunder shall govern only the EMS functions of volunteer fire departments and shall not apply to their firefighting functions or other functions. A volunteer fire department shall have in place a system for the emergency treatment or transport of motor vehicle crash victims, or other trauma victims or emergency patients to be deemed to be regularly engaged in the provision of emergency medical care. A volunteer fire department which merely offers cardiopulmonary resuscitation and other first aid and rescue in the course of firefighting and related operations shall not be deemed for that reason alone to be regularly engaged in the provision of emergency medical care.