Section 18. Any agency of the commonwealth is authorized to promulgate regulations as it deems necessary for the implementation and administration of sections sixteen and seventeen subject to the approval of the executive office of administration and finance. Failure to promulgate such regulations shall not affect any agency’s right to enter into indemnification agreements under said sections sixteen and seventeen nor the validity or enforceability of said sections or agreements.

Nothing in sections sixteen or seventeen shall affect the liability of any person under any warranty, nor the liability of an employer who is a response action contractor to any employee of such employer under any provision of law, including any provision relating to workers’ compensation.