Mass. Gen. Laws ch. 21H § 6M
The state procurement officer, the state university system and state agencies shall give preference to the purchase of equipment, supplies and other products that do not contain mercury unless there is no economically feasible non-mercury alternative that performs a similar function or unless the non-mercury product is sufficiently less energy efficient so as to result in a greater overall environmental impact. In circumstances where a non-mercury-added product is not available, preference shall be given to the purchase of products which have the least overall environmental impact in their development, manufacturing and use. This section shall not apply to the purchase of vaccines by the department of public health, its affiliates and facilities or to the purchase of refurbished medical equipment in which a mercury switch or relay is a fully integrated component.
Mass. Gen. Laws ch. 21H, § 6M