SECTION 1. Chapter 111 of the Massachusetts General Laws is hereby amended by adding the following definitions in section 1:-

“black carbon” shall mean those fine particles less than or equal to 2.5 micrometers in diameter (also known as soot).

“environmental justice population” shall mean the populations defined in section 62 of chapter 30.

“HEPA filtration” shall mean a high efficiency particulate arrestance filtration system that removes at least 99 percent of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3-10.0 microns and is equivalent to a MERV 17, MERV 18, MERV 19, or MERV 20 filter.

“MERV 16 filter” shall mean a minimum efficiency reporting value filtration system that removes at least 95 percent of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3-10.0 microns.

“particulate matter” or “particulates” shall mean a broad class of chemically and physically diverse substances that exist as discrete particles in air, including coarse, fine, and ultrafine particles.

“fine particulate matter” or “fine particulates” shall mean particulate matter less than or equal to 2.5 micrometers in diameter.

“ultrafine particulate matter” or “ultrafine particulates” shall mean particulate matter less than or equal to .1 micrometers in diameter (.1 micrometers is equivalent to 100 nanometers).

SECTION 2. Chapter 21A of the General Laws, as appearing in the 2022 Official Edition, is hereby amended by inserting after section 18A, as Section 18B, the following section:-

The department of environmental protection, in consultation with the executive office of energy and environmental affairs and department of environmental health, shall convene a technical advisory committee comprised of: residents of environmental justice populations living adjacent to major highways; academics with expertise in air monitoring, environmental health, air toxics, and air pollution; and labor representatives; for the purpose of identifying communities with high cumulative exposure burdens for toxic air contaminants and criteria pollutants. The department shall convene the technical advisory committee by December 1, 2024. The technical advisory committee shall identify the likely air pollution hotspots due to high concentrations of traffic-related air pollution throughout the Commonwealth that should be equipped with new or expanded air monitors and establish a definition of “air quality” and “air quality target pollutants” that includes, but is not limited to, consideration of criteria pollutants, black carbon, and ultrafine particulate matter.

By June 30, 2026, the department of environmental protection shall install and operate stationary air monitors in at least eight air pollution hotspots that measure for at least one of the following pollutants: black carbon, nitrogen oxides, ultrafine particulate matter. By June 30, 2027, the department of environmental protection shall establish baseline air quality in air pollution hotspots. Data from the air monitors shall be publicly accessible and provide near-time information. The department of environmental protection shall work with residents of environmental justice populations to conduct participatory action research where residents can use mobile air sensors to expand the number of locations where residents can track air quality.

Once those hotspots are determined and the baseline data is established, the department of environmental protection shall set annual targets to decrease air quality target pollutants between 2026 and 2035 to improve the air quality in that location. Air monitoring data shall be collected every three years between 2026 and 2035 to measure progress toward achieving air quality target pollutants reduction targets and make such data publicly available. By December 31, 2030, the department of environmental protection shall ensure that air pollution hotspots will have achieved air quality target pollutant concentrations that are at least 50 percent below the baseline in each hotspot and certify as such by publicly reporting compliance. By December 31, 2035, the department of environmental protection shall ensure that air quality target pollutants concentrations in hotspots are at least 75 percent below the baseline in each hotspot and certify as such by publicly reporting compliance.

The department of environmental protection, in consultation with the department of public health, shall promulgate regulations for conducting indoor/outdoor assessments monitoring exposure to ultrafine particulate matter and black carbon particulate matter concentrations present in the indoor air of existing and proposed buildings, based on the best available science about the health risks associated with ultrafine particulate matter and black carbon. The department of environmental protection’s regulations shall at minimum set forth standard procedures for conducting air dispersion modeling, managing air pollution, monitoring ultrafine particulate matter, and estimating exposure.

The provisions of this chapter may be enforced by means of an action in the superior court seeking either injunctive relief, a declaratory judgment, a writ of mandamus or any combination thereof. No such action may be commenced without the plaintiff providing written notice of the violations of this chapter to defendants at least sixty (60) days prior to filing a legal action in superior court. All persons shall have standing to commence such enforcement actions.  Reasonable attorneys’ fees shall be recoverable by all substantially prevailing plaintiffs who seek relief under this section.

SECTION 3. Section 26 of Chapter 111 shall be amended by adding the following section after the first paragraph:-

Boards of health shall require the installation of air filtration in eligible buildings located within 200 meters of a class 1, class 2 or class 3 roadway, marine terminal, airport, or a train station or train yard serving diesel locomotives. Eligible buildings include: (i) existing residential public housing; (ii) existing residential private multifamily housing with more than two tenant-occupied units; (iii) existing public schools serving students of any age in grades kindergarten through twelfth grade; (iv) existing private schools serving students of any age in grades kindergarten through twelfth grade; (v) existing charter schools serving students of any age in grades kindergarten through twelfth grade; (vi) existing college and university buildings with one or more classrooms; (vii) existing commercial buildings with businesses that have five or more full-time employees; and (viii) existing correctional facilities, including prisons and jails. Boards of health shall require that air filtration be maintained throughout the building operation.

The department of environmental protection, in consultation with the department of public health, department of elementary and secondary education, and executive office of administration and finance, shall identify funding sources to provide incentives for eligible buildings that are schools, private housing, and public housing to cover the cost of installing air filtration equipment.

Air filtration equipment installed in eligible buildings that are schools, commercial buildings greater than 20,000 square feet, and residential buildings with more than 10 units shall be MERV 16 or other equipment that removes at least the same amount of ultrafine particulate matter as a MERV 16 filter.

SECTION 4. Section 4A of chapter 15D of the General Laws, as so appearing, is hereby amended by adding the following paragraph:-

(e) The department of early education and care shall issue a new original license for a school age child care program, day care center, family day care system, group care facility or temporary shelter facility, family day care home or large family day care home which is not a part of a family day care system, as defined in section 1A of chapter 15D of the General Laws, only after the applicant has:

(1) carried out the indoor/outdoor assessment described in section 18B of chapter 21A of the General Laws and the assessment results indicate the concentration of fine, ultrafine, and black carbon particles in indoor air is or will be mitigated to at least 80 percent below outdoor air concentrations; or

(2) installed a MERV 16 filter in mechanical ventilation system or standalone HEPA filtration or acceptable mitigation to be determined by the department.

(f) No license shall be issued until acceptable mitigation has been installed and is functioning.

SECTION 5. Section 1A of chapter 40A of the General Laws, as so appearing is hereby amended by inserting before the definition of “permit granting authority” the following definitions:-

“construction” shall mean new construction or rehabilitation up to 50 percent of assessed value.

“hospital” shall mean any institution in the Commonwealth of Massachusetts, however named, whether conducted for charity or for profit, which is advertised, announced, established or maintained for the purpose of caring for persons admitted thereto and staying overnight for diagnosis or medical, surgical or restorative treatment which is rendered within said institution; but shall not include clinics, day surgery centers, dialysis centers, or other such health care facilities which do not admit patients overnight.

“long-term care facility” shall mean any institution whether conducted for charity or profit which is advertised, announced or maintained for the express or implied purpose of providing three or more individuals admitted thereto with long-term resident, nursing, convalescent or rehabilitative care; supervision and care incident to old age for ambulatory persons; or retirement home care for elderly persons. Long-term care facility shall include convalescent or nursing homes, rest homes, and charitable homes for the aged.

“particulate matter mitigation” shall mean strategies, structural and nonstructural, that verifiably reduce indoor ultrafine particle levels by 80 percent, relative to outdoor levels.

“publicly funded” shall mean any entity or institution which receives federal, state or municipal monies, grants, and/or subsidies.

“publicly subsidized” shall mean any project receiving any form of direct funding, loan, loan guarantee, tax credit, TIF funding, publicly bonded funds, or property tax incentives, issued or granted by any public or quasi-public entity.

“school” shall mean any public or private institution primarily engaged in the education of persons aged 18 years and younger. This definition does not include institutions of higher education.

SECTION 6. Section 94 of chapter 143 of the General Laws, as so appearing, is hereby amended by inserting the following paragraphs after section (r):-

(s) No permit granting authority shall grant a building permit for any proposed residential development, hospital, school, long-term care facility, school aged child care program, day care center, family day care home or large family day care home which is not a part of a family day care system, family day care system, or group care facility or temporary shelter facility as defined in section 1A of chapter 15D of the General Laws unless:

(a) the owner or applicant carries out an indoor/outdoor particulates assessment consistent with the regulations adopted pursuant to section 18B of chapter 21A of the General Laws, and the assessment results indicate that the concentration of ultrafine particulate matter and black carbon is or will be mitigated to at least 80 percent below outdoor concentrations; or

(b) the owner or applicant has installed a MERV 16 filter in the building’s mechanical ventilation system.

SECTION 7. Subsection a of section 6 of chapter 70B of the General Laws, as so appearing, is hereby amended by inserting after subparagraph (6) the following paragraph:-

(7) If the school project includes structures, apart from parking structures and accessory structures, as defined in Section 21 of Chapter 17 of the General Laws or a train station or train yard serving diesel locomotives, the applicant shall:

(a) carry out the indoor/outdoor particulates assessment described in section 18B of chapter 21A of the General Laws and the assessment results indicate that the concentration of ultrafine particulate matter and black carbon is or will be mitigated to at least 80 percent below outdoor concentrations; or

(b) install a MERV 16 filter in the mechanical ventilation system or standalone HEPA filtration or acceptable mitigation to be determined by the department.

SECTION 8. Section 51 of Chapter 111 of the General Laws, as so appearing, is hereby amended by inserting after the second paragraph the following paragraph:-

No original license shall be issued to establish a hospital so as to place structures inhabited by patients unless the developer:

(1) has carried out the indoor/outdoor particulates assessment described in section 18B of chapter 21A of the General Laws and the assessment results indicate that indoor ultrafine particulate matter and black carbon levels are or will be mitigated to at least 80 percent below that of outdoor levels. In the case of a facility previously licensed as a hospital in which there is only a change in ownership, no such particulates assessment shall be required, in the absence of expansions or new construction; or

(2) has installed a MERV 16 filter in the mechanical ventilation system or standalone HEPA filtration or acceptable mitigation to be determined by the department.

SECTION 9. Section 71 of Chapter 111 of the General Laws, as so appearing, is hereby amended by inserting after the second paragraph the following paragraph:-

No original license shall be issued to establish a convalescent or nursing home, rest home or charitable home for the aged so as to place residential structures unless the developer:

(1) has carried out the particulates assessment described in section 18B of chapter 21A of the General Laws and the assessment results indicate indoor ultrafine particulate matter and black carbon levels are or will be mitigated to at least 80 percent below those of outdoor levels. In the case of a facility previously licensed in which there is only a change in ownership, no such health risk assessment shall be required, in the absence of expansion or new construction; or

(2) has installed a MERV 16 filter in the mechanical ventilation system or standalone HEPA filtration or acceptable mitigation to be determined by the department.

SECTION 10. Section 1 of chapter 111 of the General Laws is hereby amended by inserting the following definitions:-

“Indoor mold,” visible living or dead fungi or related products or parts, including spores, hyphae, and mycotoxins, on an interior surface of a building, including common spaces, utility spaces, HVAC, or other systems.

“Indoor mold assessment,” an indoor mold assessment conducted by an indoor mold remediation professional.

“Indoor mold hazard,” indoor mold growth of ten square feet (10 ft.2) or more in an affected area.

“Owner,” as provided in section 189A of chapter 111.

“Premises,” any residential premises, dwelling unit, or residential property.

SECTION 11. Section 127A of chapter 111 shall be amended to add the following sections after the second paragraph:-

Section 1.

(a) An owner leasing a premises shall notify tenants of the premises and prospective tenants who are about to enter an agreement to rent the premises about the hazards of indoor mold as follows:

(1) The department shall, by July 1, 2024, prepare a standard notification brochure and such other materials as may be necessary to inform occupants and owners about the hazards associated with indoor mold; measures which can be taken by occupants and owners to reduce the risk of indoor mold; and tenants’ rights and owners’ obligations pursuant to sections 127A, 127B, and 127C of chapter 111, inclusive, and regulations promulgated thereunder. Such materials shall also describe the need for tenants to promptly notify owners of the appearance of indoor mold. The department shall produce these materials in multiple languages other than English to accommodate the diverse multicultural population of Massachusetts.

(2) The department shall, by July 1, 2024, prepare a disclosure form for owners to provide the following notice to tenants and prospective tenants:

(i) Prior violations of the State Sanitary Code involving indoor mold or moisture, within the past three years; and

(ii) Current instances of indoor mold on the premises, of which the owner knows, or has reasonable cause to believe exist.

(3) Effective August 1, 2025, prior to entering into a tenancy agreement, the owner of a premises, or such other person to whom rent is to be regularly paid, shall provide any prospective tenant who is about to enter such an agreement to rent the premises with, and the prospective tenant shall sign prior to entering into a tenancy agreement:

(i) A copy of the materials specified in subsection (1);

(ii) A written disclosure on the form specified in subsection (2) regarding any existing indoor mold on the premises, when the owner knows, or has reasonable cause to believe, that such indoor mold is present.

(4) Effective August 1, 2025, prior to any renewal of an existing tenancy agreement, the owner of premises, or such other person to whom rent is to be regularly paid, shall provide the tenant with the materials specified in subsection (3).

(b) All persons selling a premises shall, prior to the signing of a purchase and sale agreement, provide the prospective purchaser with the materials specified in subsection (3). The prospective purchaser shall sign these materials prior to the signing of a purchase and sale agreement. The department may adapt these materials as appropriate for the context of real estate purchases.

Section 2. Inspection Requirements.

(a) Notwithstanding sections 3(b) and 4, an owner shall inspect or hire a third party to inspect for indoor mold in all occupied premises and in common areas at least once a year between the months of June and August and more often, if necessary, such as when, in the exercise of reasonable care, an owner knows or should have known of a condition that is reasonably foreseeable to cause indoor mold, or an occupant makes a complaint concerning a condition that is likely to cause indoor mold or requests an inspection, or the department issues a notice of violation or orders the correction of a violation that is likely to cause indoor mold.

(b) An owner who receives written or electronic notice from a tenant that indoor mold or suspected indoor mold exists in the premises or in a common area of the property shall inspect the property within five (5) calendar days.

(c) An owner who conducts or provides for an inspection under subsections (a) and (b) within five (5) calendar days of such inspection shall:

(1)  Provide written, in the form of paper or electronic, notice to the tenant that states:

(i) That the owner inspected the apartment for indoor mold; and

(ii) Whether the owner found indoor mold and, if so, whether the indoor mold constitutes an indoor mold hazard.

(2) Report to the local board of health:

(i) The information specified under subsection (c)(1), provided the inspection is an annual inspection required under subsection (a), or any other inspection where the inspection reveals an indoor mold hazard.

(ii) The receipt of any written or electronic complaint from the tenant regarding indoor mold or suspected indoor mold.

(d) Local boards of health will keep a record of, and make public, the information received under subsection (c)(2) through a publicly accessible online database.

Section 3. Remediation Requirements.

(a) The presence of indoor mold in a leased premises constitutes a violation of the State Sanitary Code. Owners of leased premises shall take reasonable measures to keep such premises free from indoor mold and from any condition conducive to indoor mold and shall take reasonable measures to prevent the reasonably foreseeable occurrence of such conditions and shall expeditiously take reasonable measures to remediate such conditions and any underlying defect, when such underlying defect exists, consistent with this section and the rules promulgated thereunder.

(b) If an inspection or examination as provided for in section 3 or the State Sanitary Code reveals the presence of indoor mold, the owner shall:

(1) Cause the indoor mold to be remediated in accordance with subsections (c) or (d), as applicable;

(2) Begin necessary remediation or contract in writing with a third party within five (5) days of the inspection provided for in section 3 or receiving notice of a violation pursuant to the State Sanitary Code, unless a shorter timeframe is ordered by the local board of health; and

(3) Make a good faith effort to substantially correct all violations within thirty (30) days of the inspection provided for in section 3 or receiving notice of a violation pursuant to the State Sanitary Code, unless a shorter timeframe is ordered by a local board of health.

(c) If remediation of indoor mold is required under subsection (b) and the indoor mold is not an indoor mold hazard, the owner shall:

(1) Remediate the indoor mold in accordance with the guidelines established under subsection (e)(2); and

(2) Within five (5) days of the completed remediation of the indoor mold:

(i) Provide written or electronic notice to the tenant stating that the indoor mold is remediated; and

(ii) Report to the local board of health that the indoor mold is remediated. Local boards of health will keep a record of, and make public, this report.

(d) If remediation of indoor mold is required under subsection (b) and the indoor mold is an indoor mold hazard, the owner shall:

(1) Cause an indoor mold remediation professional to remediate the indoor mold hazard. The indoor mold remediation professional shall remediate the indoor mold hazard in accordance with the performance standards and work practices established under subsection (e)(1); and

(2) Within five (5) days of the completed remediation of the indoor mold:

(i) Provide written or electronic notice to the tenant stating that the indoor mold is remediated; and

(ii) Inform the local board of health of the violation and request an inspection following the remediation, provided that the local board of health is not aware of the violation and does not plan to conduct a follow-up inspection pursuant to the State Sanitary Code. Local boards of health will keep a record of, and make public, this report, through a publicly accessible online database.

(e) Consistent with applicable U.S. Environmental Protection Agency or U.S. Department of Labor, Occupational Safety and Health Administration guidelines and regulations relating to the assessment and remediation of mold, within one year of the effective date the department shall:

(1) Establish minimum performance standards and work practices for conducting professional indoor mold remediation in Massachusetts, including the use of a moisture meter before and following remediation to ensure that moisture levels for building materials are at appropriate levels as determined by the department.

(2) Establish guidelines for the safe and effective remediation of indoor mold that is not an indoor mold hazard. At a minimum, these guidelines shall require an owner to:

(i) Investigate and correct any underlying defect, including moisture or leak conditions, that are causing or may cause mold violations;

(ii) Remove or securely cover with plastic sheeting any furniture or other items in the work area that cannot be removed;

(iii) Minimize the dispersion of dust and debris from the work area to other parts of the dwelling unit through methods such as: sealing ventilation ducts/grills and other openings in the work area with plastic sheeting; isolating the work area with plastic sheeting and covering egress pathways; cleaning or gently misting surfaces with a dilute soap or detergent solution prior to removal; the use of HEPA vacuum-shrouded tools or a vacuum equipped with a HEPA filter at the point of dust generation;

(iv) Clean mold with soap or detergent and water;

(v) Remove and discard materials that cannot be cleaned properly;

(vi) Properly remove and discard plastic sheeting, cleaning implements, and contaminated materials in sealed, heavy weight plastic bags;

(vii) Clean any remaining visible dust from the work area using wet cleaning methods or HEPA vacuuming; and

(viii) Leave the work area dry and visibly free from mold, dust, and debris.

(f) Failure of the department to issue minimum performance standards, work practices, and guidelines shall not excuse an owner from the remediation requirements under this section.

(g) If mold remediation required under subsection (b) results in the premises being uninhabitable, the owner shall pay for the cost of a hotel or other reasonable alternative housing arrangement during the mold remediation for each 24-hour period for which the premises is uninhabitable.

Section 4. Fines.

(a) An owner who violates any provision of this section, or the rules promulgated thereunder, shall be punishable by fine as follows:

(1) By a fine of not less than $250 nor more than $500 for each violation of section 2, section 3, and section 4(b), 4(c), and 4(d).

(2) If remediation is not completed within the required timeframe under section 4(b), each subsequent day until remediation is completed constitutes a separate violation under subsection (a)(1).

Section 5. Indoor Mold Assessment and Remediation Fund.

(a) There is established the Indoor Mold Assessment Fund, which shall be administered by the department in accordance with subsection (c) of this section.

(b) The Fund shall consist of the revenue from: fees collected in accordance with subsection (d) of section 4; fines collected in accordance with section 6; and any other money accepted for the benefit of the Fund.

(c) The Fund shall be used to meet the department’s education and research support obligations under section 6; and to provide financial assistance grants to low-income residents for the purpose of having a professional mold assessment conducted in their premises in the event that the owner fails to comply with the requirements in sections 2 through 4 or for small property owners of buildings up to nine units for the purpose of covering mold assessments and inspections.

Section 6. Education and Research Support.

(a) The department shall create educational materials and guidance to support owners in meeting their obligations under sections 2 through 4.

(b) The department shall promulgate a comprehensive written procedure to guide local boards of health and code enforcement agencies in implementing and enforcing sections 2 through 7.

(c) The department shall institute an educational and publicity program, to inform the general public, and particularly owners, tenants, local boards of health and code enforcement agencies, and health services personnel, of: the dangers of mold; the causes of mold and how to identify these causes; occupant behaviors that can contribute to indoor mold growth; and methods for preventing and remediating mold growth.

(d) The department shall prioritize the use of available funding sources to fund research focused on the health impacts of mold and strategies for mitigating mold.

(e) The department shall seek comments from time to time from residents of environmental justice populations as defined by section 62 of chapter 30 of the general laws regarding mold and air quality concerns.

Section 7. Violations/Remedies for Injured Tenants.

(a) In a private cause of action, claim, or defense by a tenant against an owner for a violation under this Section:

(1) A professional indoor mold assessment finding indoor mold contamination in a leased premises or a common area of the property shall create a rebuttable presumption of a violation of the owner's obligation to maintain the premises as required under this Section and the State Sanitary Code. To establish the presumption, the tenant must demonstrate that the owner received a professional indoor mold assessment in written or electronic form that determined that indoor mold contamination existed in the tenant's leased premises.

(2) When ruling in favor of a tenant with respect to a violation of this Section or the State Sanitary Code based on a professional indoor mold assessment, the court shall have discretion to reimburse indoor mold assessment costs and award attorney fees and court costs to the tenant. The court may award treble damages to a tenant when:

(i) The tenant discovered the indoor mold;

(ii) A professional indoor mold assessment determined that indoor mold contamination existed in the tenant's premises;

(iii) The owner received the indoor mold assessment in written or electronic form;

(iv) The owner did not remediate the indoor mold within the timeline required under section 4; and

(v) The court finds that the residential property owner acted in bad faith.

(b) The housing court department established pursuant to section 1 of chapter 211B shall establish a dedicated process to handle claims involving a violation of this Section or violation of the State Sanitary Code involving mold. This process shall include the opportunity for mediation prior to a hearing.

SECTION 12. (1) Notwithstanding any special or general law, rule or regulation to the contrary the board of building regulations and standards shall, commencing with the next edition of the International Energy Conservation Code adopted after January 1, 2022 under section 94 of chapter 143 of the General Laws, adopt, approve, codify, and publish mandatory building standards:

(a) for mandatory building standards for the installation of air filtration systems at a minimum of MERV 16; and

(b) do not permit the installation of gas stoves for use in residential construction.

(2) In proposing and adopting standards and regulations under this section, the Board of Building Regulations and Standards shall actively consult with interested parties, including, but not limited to, the Department of Public Health and the Department of Energy Resources.