Term State 

Regulatory 

Citation

Definition

Actual 

Construction

(already in SIP)

7.54 means in general, initiation of physical on-site construction

activities of any facility subject to the requirements of 310 

CMR 7.00, which are of a permanent nature. Such 

activities include, but are not limited to, installation of 

building supports and foundations, laying underground 

pipework and construction of permanent structures.

Adhesion 

Promoter

7.18 means a coating designed to facilitate the bonding of a 

primer or topcoat on surfaces such as trim moldings, door 

locks, and door sills, where sanding is impracticable, and 

on plastic parts and the edges of sanded areas.

Administrator 7.26(16), 7.27 means the administrator of the U.S. Environmental 

Protection Agency or his designee.

Alter or 

Alteration

Throughout means any physical change or change in the method of 

operation (including modification or reconfiguration of an 

emissions unit, change in the raw material used or change 

in the operating rate) which would result in an increase in 

potential emissions or an increase in ambient air impacts 

(i.e., reduced stack height).

Alternative Fuel 7.22, 7.45, 7.54 means any fuel designated as such on an annual list issued 

by the Department, including methanol, denatured ethanol, 

and other alcohols; mixtures containing 85% or more by 

volume of methanol, denatured ethanol, and other alcohols 

with gasoline or other fuels; natural gas; liquified 

petroleum gas; hydrogen, coal-derived liquid fuels; fuels 

(other than alcohol) derived from biological materials; 

electricity (including electricity from solar energy); and 

any other fuel that the Department determines is 

substantially not petroleum.

Alternative Fuel 

Vehicle

7.45 (MA 

Green Fleet 

Program)

means a motor vehicle as defined in M.G.L. c. 90, § 1, 

which the Department determines to:

(a) operate exclusively on an alternative fuel; and

(b) meets applicable state and federal safety and emission 

standards.

Anti-glare Safety 

Coating

7.18 means a low gloss coating formulated to eliminate glare

for safety purposes on interior surfaces of a vehicle, as 

specified under the U.S. Department of Transportation 

Motor Vehicle Safety Standards.

Definitions submitted by Massachusetts for Incorporation into the SIP
Aqueous Cleaner 7.18 means a cleaning fluid or device using a cleaning fluid that 

is composed of soap and/or other water-soluble materials 

in a water solution.

Asbestos 7.09, 7.15 means all asbestiform varieties of the mineral family called 

silicates including: serpentinite (chrysotile), riebeckite 

(crocidolite), cummingtonite-grunerite-(atmosite),

anthophyllite, and actinolite- tremolite.

Asbestoscontaining 

Material

7.09, 7.15 means friable asbestos and any material containing 1% or 

more asbestos by area as determined by a laboratory using 

USEPA approved methods. This term includes but is not 

limited to sprayed-on and troweled-on materials applied to 

ceilings, walls, and ceilings, walls, and other surfaces, 

insulation on pipes, boilers, tanks, ducts, and other

equipment, structural and non-structural members, tiles, 

shingles or asbestos-containing paper.

Automotive 

Refinishing 

Facility

7.18 means any facility at which the interior or exterior bodies 

of automobiles, motorcycles, trucks, mobile equipment, or 

vans are re-painted. This definition includes refinishing 

operations that travel to various locations, that refinish new

vehicles damaged in transit before their initial sale, and 

that refinish aftermarket vehicles.

Bakery 7.18(2a) means a facility consisting of one or more ovens for the 

baking of bread or other yeast leavened products.

Capture 

Efficiency

7.02, App B means the ability of a building, enclosure or system to 

capture air contaminants within the building, enclosure or 

system before the air contaminants are directed

to an air pollution control device. Capture efficiency is 

determined in accordance with EPA Reference Test 

Method Number 204, as specified in 40 CFR Part 51 

Appendix M, or by other methods approved by the 

Department and EPA.

CEMS 7.08, 7.19 means a continuous emissions monitoring system.

CFR Throughout means the Code of Federal Regulations.

Combined Cycle 

Combustion 

Turbine

7.19 means any combustion turbine, including the

duct burner portion thereof, in which heat is recovered 

from the exhaust gases to heat water or generate steam.

Compliance 

Certification

Throughout means a statement detailing the compliance status of the

emission unit or facility in regards to each applicable 

requirement, signed by a responsible official of the facility 
as being complete, accurate and true to the best knowledge 

of the signatory.

Construct or 

Construction

Throughout means any physical change or change in the method of

operation (including fabrication, erection, installation, 

demolition, or modification of an emissions unit) which 

would result in an increase in potential emissions.

Cooling Tower 7.02 as used in 310 CMR 7.02(2)(g)6. means, an open water 

recirculation device that uses fans or natural draft to draw 

or force ambient air through the device to cool warm water

by direct contact.

Dry Bottom 7.19 means a furnace design in which the coal-fired unit 

equipped with an ash disposal hopper bottom with 

sufficient cooling surface so that the ash particles 

impinging on the furnace walls or hopper bottom can be 

removed in a dry state.

Duct Burner 7.26, 7.32 means a device that combusts fuel and that is placed in the 

exhaust duct from another source, such as a stationary gas 

turbine, internal combustion engine, kiln etc., to allow the 

firing of additional fuel to heat the exhaust gases before the 

exhaust gases enter a heat

recovery steam generating unit.

Elastomeric 

Coating 

7.18 means a coating that is designed for application over 

flexible parts, such as elastomeric bumpers.

Emergency or 

Standby Engine

7.02, 7.03, 7.12, 

7.26

for the purposes of 310 CMR 7.02(8)(i) and 7.03(10),

means any stationary internal combustion engine which 

operates as an emergency or standby mechanical or 

electrical power source. A load shaving unit, peaking 

power production unit or a standby engine in an energy 

assistance program is not an emergency or standby engine 

under this definition.

Emission 

Statement 

7.12 is a certification submitted by the owner or operator of a 

facility that describes the actual annual emissions of VOC 

and/or NOx from the facility as well as the

average Ozone Season daily emissions from the facility.

Energy Input 

Capacity

7.02(2), 

7.04(2), 7.05, 

7.06, 7.12, 7.19

means the ability of a fuel utilization facility, based on the

Higher Heating Value (HHV) of the fuel, to combust a 

stated maximum amount of fuel on a steady state basis, as 

determined by the physical design and characteristics of 

the fuel utilization facility and does not include the energy 

input from preheated combustion air, recirculated flue
gases, or exhaust gases from other sources.

EPA Throughout means the United States Environmental Protection 

Agency.

Existing Facility 7.02, 7.26 for the purposes of 310 CMR 7.02(8), means any facility 

that is in operation on or before June 1, 1972, or any 

proposed facility of which the construction,

substantial reconstruction or alteration of which has been 

approved in writing by the Department

on or before June 1, 1972. All facilities as specified in the 

Federal Register, Volume 36, No. 247, December 23, 

1971, the construction or modification of which was 

initiated after August 17, 1971 shall not be defined as 

existing facilities.

Face Firing 7.19 (?) means a furnace firing design in which the burners are 

mounted in an array on one or more vertical walls 

including

(a) opposed firing, where the burners are mounted on two 

opposite walls; and

(b) single-wall firing, where the burners are mounted on 

only one wall.

Facility Throughout means any installation or establishment and associated 

equipment, located on the same, adjacent or contiguous 

property, capable of emissions; and for the purpose of 310 

CMR 7.15, it means any structure, installation, building, 

equipment, or ship.

Federally 

Enforceable

Throughout means all limitations and conditions which are enforceable 

by the Administrator, including but not limited to, those 

requirements developed pursuant to

40 CFR Part 60 (New Source Performance Standards), 40 

CFR Part 61 (National Emission Standards for Hazardous 

Air Pollutants), 40 CFR Part 63 (National Emission 

Standards for Hazardous Air Pollutants for Source 

Catergories), 40 CFR Parts 72 through 80 (Acid Rain

Program) and requirements within the Massachusetts State 

Implementation Plan. Federally

enforceable requirements also include those requirements 

in operating permits issued either

pursuant to 40 CFR part 71 or under 310 CMR 7.00: 

Appendix C, (except those listed as state enforceable only) 

any permit requirements established pursuant to 40 CFR 
52.21 (Prevention of significant deterioration of air 

quality), under plan approval requirements in either 310 

CMR 7.02 or 310 CMR 7.00: Appendix A. Federally 

enforceable limitations and conditions can also be 

contained in either a permit restriction issued under 310 

CMR 7.02(9), 7.02(10), 7.02(11) or equipment installed 

under 310 CMR 7.03, that has been made federally 

enforceable after the EPA has approved 310 CMR 7.02 

and 7.03 into the Massachusetts SIP.

Federal Potential 

to Emit or 

Federal Potential 

Emissions

7.02 means the maximum capacity of a stationary source to 

emit a regulated pollutant under its physical and

operational design. Any physical or operational limitation 

on the capacity of the source to emit

a regulated pollutant, including air pollution control 

equipment and restriction on hours of operation or on the 

type or amount of material combusted, stored, or 

processed, shall be treated as part of its design only if the 

limitation or the effect it would have on emissions is 

federally enforceable. To be federally enforceable, a 

limitation on any facility's capacity to emit a pollutant shall 

include testing, monitoring, and recordkeeping procedures 

sufficient to demonstrate compliance with the limitations. 

Examples of permit or SIP limitations generally considered 

federally enforceable are limitations on the allowable 

capacity of the equipment,

requirements for the installation, operation and 

maintenance of pollution control equipment, limits on 

hours of operation, and restrictions on amounts of 

materials combusted, stored, or produced. To be federally 

enforceable, restrictions on operation, production, or 

emissions must be stated in terms of the shortest averaging 

time that can be used as a practical matter, e.g., pounds per 

hour, or gallons per hour, and they must be tied to other 

enforceable operating

restrictions at the source. General limitations on potential 

to emit, such as yearly limits (e.g., in tons per year), by 

themselves, are not considered federally enforceable. The 

use of hourly, daily, weekly, or monthly rolling limits are 

generally acceptable. Any federally enforceable limitations 

or conditions must be enforceable as a practical matter, 

ensure continuous
compliance with the restrictions, and include adequate 

testing, monitoring, and record keeping procedures 

sufficient to demonstrate compliance with the limitations 

or conditions of an applicable federally enforceable 

document described above. Fugitive emissions, to the 

extent quantifiable, are included in determining the 

potential to emit of a stationary source. Secondary

emissions do not count in determining the potential to emit 

of a stationary source.

Ferrous Cupola 

Foundry

7.02 means a vertical cylindrical furnace using pig iron, scrap

iron, scrap steel and coke as charging components. Ferrous 

Cupola Foundries can be separated into “Jobbing” 

Foundries and “Production” foundries. Jobbing foundries 

run intermittently for just long enough at one time to pour 

the molds that are ready on the foundry floor on a job-by

job basis. Production foundries will melt metal 

continuously and pour to a succession of molds that are 

constantly being prepared to receive the flow of molten 

iron.

Four-Stage 

Coating System

7.18(28) means a topcoat system composed of a colored basecoat,

two semi-transparent midcoats, and a final transparent 

clearcoat. For compliance purposes, the

VOC content of four-stage coating systems shall meet the 

emission limitation for three or four stage

topcoats in Table 7.18(28)(c), and is calculated according 

to the following formula:

Where:

VOC T4-stage is the weighted average of the VOC 

content, as applied, in the basecoat, midcoat, and clearcoat 

system.

VOCbc is the VOC content, as applied, of any given 

basecoat.

VOCmc1 is the VOC content, as applied, of the first 

midcoat.

VOCmc2 is the VOC content, as applied, of the second 

midcoat.

2VOCcc is twice the VOC content, as applied, of any 

given clearcoat.
VOC T4-stage = (VOC bc + VOC mc1 + VOC mc2 + 2 VOC cc) 

 _____________________________________

 5

Friable 

AsbestosContaining 

Material

7.09 means any dry material containing 1% or more asbestos by 

area, as determined by a laboratory using USEPA 

approved methods, that hand pressure can crumble, 

pulverize, or reduce to powder.

Fuel Cell 7.28, 7.32 means an electrochemical device that converts the 

chemical energy in a fuel into electricity and heat.

Fugitive 

Emissions

7.03, 7.08, 7.54, 

7.71, App A, B, 

C 

means those emissions which could not reasonably pass 

through a stack, chimney, vent, or other functionally 

equivalent opening.

Glass 7.19 means a hard amorphous inorganic substance made by 

fusing silicates, and sometimes borates and phosphates, 

with certain basic oxides.

Glass Melting 

Furnace

7.19(11) means equipment using heat for the production of glass. A 

unit comprising a refractory vessel in which raw materials 

are charged, melted at high temperature, refined, and 

conditioned to produce molten glass.

Halogenated 

Organic 

Compound

7.02, 7.03, 7.18 is any compound of carbon (excluding metallic

carbides or carbonates and ammonium carbonate) 

combined with a halogen. For purposes of 310 CMR 7.12 

and 310 CMR 7.18, halogenated organic compounds 

(HOC) are the following specific chemicals: methylene 

chloride, perchloroethylene (tetrachloroethylene), CFC-11

(trichlorofluoromethane), CFC-12

(dichlorodifluoromethane), CFC-22

(chlorodifluoromethane), FC-23 (trifluoromethane), CFC114 (dichlorotetrafluoro- ethane), and CFC-115

(chloropentafluoroethane).

Hardener 7.18(28),7.25 means an additive designed to promote a faster cure of 

coatings which cure by chemical cross-linking of the resin 

components.

Hazardous Air 

Pollutant (HAP

7.02, 7.03, 7.12, 

7.26, 7.38, App 

B

means an air contaminant designated by EPA under

42 U.S.C. 7412, as modified by EPA in 40 CFR Part 63, 

Subpart C (40 CFR 63.60 through .69). That list is 

incorporated by reference herein, together with all 

amendments and supplements thereto. A copy of the list is 

available from the Department.
Heat Release 

Rate

7.19(4) means the steam generating unit design heat input capacity 

(in Btu per hour) divided by the furnace volume (in cubic 

feet); the furnace volume is that volume bounded by the 

front furnace wall where the burner is located the furnace 

side waterwall, and extending to the level just below or in 

front of the first row of convection pass tubes.

Impact Resistant 

Coating

7.18 means a coating designed to resist chipping caused by road

debris.

Lean Burn 

Engine

7.19 means a stationary reciprocating internal combustion 

engine in which the amount of O2 in the engine exhaust 

gases is 1.0% or more.

Lowest 

Achievable 

Emission Rate 

(LAER)

App A means, for any source, the more

stringent rate of emissions based on the following:

(a) The most stringent emissions limitation which is 

contained in any state SIP for such class or category of 

stationary source, unless the owner or operator of the 

proposed stationary source demonstrates that such 

limitations are not achievable; or

(b) The most stringent emissions limitation which is 

achieved in practice by such class or category of stationary 

source. This limitation, when applied to a modification, 

means the lowest achievable emissions rate for the new or 

modified emissions units within a stationary source. In no 

event shall LAER allow a proposed new or modified 

stationary source to emit any pollutant in excess of the 

amount allowable pursuant to applicable New Source 

Performance Standards of 40 CFR Part 60.

Malfunction 7.08, 7.24, 7.40 means any sudden, infrequent, and not reasonably 

preventable failure of air pollution control and monitoring

equipment, process equipment, or a process to operate in a

normal or usual manner. Failures that are caused in part by 

poor maintenance or careless operation are not 

malfunctions.

Maximum 

Achievable 

Control 

7.02, 7.12, 7.26, 

7.40, App B

means the standard established by the Administrator 

pursuant to the Clean Air Act, §§ 112 and 129 (42 U.S.C. 

7412 and 42 U.S.C. 7429), that represents the maximum 

degree of reduction in emissions of hazardous air 
Technology pollutants determined, after examination of economics, 

health, and environmental impacts, to be achievable for 

new or existing sources in the category or sub-category to 

which the emission standard applies. MACT Standards 

may be determined by the Department pursuant

to 40 CFR 63 Subpart B.

Maximum 

Design Capacity

7.02 means the rated design capacity, operating rate or

production rate of an emission unit as determined by the 

manufacturer of that unit or other method approved by the 

Department.

Mobile 

Equipment 

App C, and in 

the def of 

automotive 

refinishing

means, for the purposes of 310 CMR 7.18(28), any 

equipment that is physically capable of being driven or 

drawn upon a highway including but not limited to

construction vehicles (such as mobile cranes, bulldozers 

and concrete mixers); farming equipment (such as tractors 

and plows); hauling equipment (such as truck trailers, 

utility bodies and camper shells) and miscellaneous 

equipment (such as street sweepers and golf carts).

MW 7.08, 7.26, 7.27, 

7.28, 7.32, 7.33, 

7.70

means megawatt or a unit of electrical power equal to one 

million watts.

Natural Draft 

Opening

Definitions only means any permanent opening in an enclosure that remains

open during operation of the emission unit and is not 

connected to a duct in which a fan is installed.

Nonattainment 

Area

App A means an area designated by the EPA as not meeting the 

National Ambient Air Quality Standard for a criteria 

pollutant pursuant to the Clean Air Act, § 107 (42 U.S.C. 

7407) and 40 CFR Part 81. The current Massachusetts 

attainment status is published at 40 CFR 81.322, Subpart C 

- Section 107 Attainment Status Designations.

Nonattainment 

Review

7.02, 7.26, 7.27, 

7.28, 7.29, App 

A

is plan review for major sources and major modifications 

as defined and described in 310 CMR 7.00: Appendix A.

Non-Criteria 

Pollutant

7.02 is any air contaminant that is not listed as a criteria 

pollutant.

Non-road 

Vehicle

7.45 (MA 

Green Fleet 

program)

means any motor vehicle and equipment which is not 

primarily designed or intended for operation on public 

roadways to provide transportation.

Potential Throughout means the maximum capacity of a facility or a stationary 
Emissions or 

Potential To 

Emit

source to emit any air contaminant or pollutant under its 

physical and operational design. Any physical or 

operational limitation on the capacity of the facility or

stationary source to emit any air contaminant or pollutant, 

including air pollution control equipment and/or 

restrictions on hours of operation, or on the type or amount 

of material combusted, stored or processed, shall be treated 

as part of the design only if the limitation is specifically 

stated in the facility's or stationary source's plan 

approval(s), approved emission control plan(s), operating 

permit, certification(s), restricted emission status, 

notification(s) and applicable regulations, or in the case of 

de minimis sources, in records established and

maintained at the facility or stationary source pursuant to 

310 CMR 7.02(2)(b). Fugitive emissions, to the extent 

quantifiable, are included in determining the potential 

emissions or the potential to emit of a facility or stationary 

source; secondary emissions are not included.

Pretreatment 

Wash Premier

7.18(28) means the first coat applied to bare metal if solvent-based

primers will be applied. This coating contains a minimum 

of 0.5% acid by weight, is necessary to provide surface 

etching, and is applied directly to bare metal surfaces to 

provide corrosion resistance.

Primer Sealer 7.18(28) means a coating that improves the adhesion of the topcoat, 

provides corrosion resistance, promotes color uniformity, 

and resists penetration by the topcoat.

Primer Surfacer 7.18(28) means a coating that fills in surface imperfections and 

builds a film thickness in order to allow sanding.

Reducer 7.26, 7.18(28) means a solvent added to dilute a coating, usually for the 

purpose of lowering its viscosity.

Regenerative 

Cycle 

Combustion 

Turbines

7.19 means any stationary combustion turbine which recovers 

heat from the combustion turbine exhaust gases to preheat 

the inlet combustion air to the combustion turbine.

Repowering 7.19 means the replacement of an emission unit with a new unit 

that is less polluting and more efficient than the unit which 

is being replaced.

Rich Burn 

Engine

7.19 means any stationary reciprocating internal combustion 

engine that is not a lean burn engine.
Simple Cycle 

Combustion 

Turbine

7.19 means any stationary combustion turbine which does not 

recover heat from the combustion turbine exhaust gases to 

heat water or generate steam.

Single-stage 

Topcoat

7.18 means a topcoat consisting of only one coating.

Soap 7.18, 7.25 means cleansing agents made of the alkali metal salts of 

fatty acids having from ten to 18 carbon atoms.

Specialty 

Coating

7.25, 7.18(28) means a product which is necessary due to unusual job 

performance requirements. These coatings or additives 

include, but are not limited to, adhesion promoters,

uniform finish blenders, elastomeric materials, impact 

resistant coatings, underbody coatings, weld through 

primers, gloss flatteners, bright metal trim repair, and antiglare/safety coatings.

Stationary 

Combustion 

Turbine

7.19 means any stationary internal combustion engine

which operates with a rotary motion, including any simple 

cycle turbine, regenerative cycle turbine, or any turbine 

portion of a combined cycle steam/electric generating 

system that is not self propelled.

Stationary 

Reciprocating 

Internal 

Combustion 

Engine

7.12, 7.18, 7.19, 

7.26

means any reciprocating internal combustion engine. It 

does not include an engine that is regulated by EPA

as a non-road engine pursuant to 42 U.S.C. 7543(e) and 42 

U.S.C. 7547(e) or is self-propelled.

Stencil Coating 7.18 means an ink or pigmented coating which is rolled or 

brushed onto a template or stamp in order to add 

identifying letters, symbols, or numbers to motor vehicles, 

or their parts or components.

Stoker 7.19 means a boiler/furnace design that incorporates a feeding 

mechanism, fuel distribution and ash residue collection 

system for the purpose of introducing solid fuel into the 

combustion zone of the boiler/furnace by feeding the fuel 

onto a grate.

Surface 

Preparation 

Product

7.02, 7.03, 

7.18(28)

means a product formulated to dissolve and remove tar, 

grease, wax, and other hydrophobic contaminants from a 

surface prior to application of a primer.

Tangential Firing 7.19 means a furnace firing design where the burners are 

mounted at the corners of the furnace chamber.
Three-Stage 

Coating System

7.18(28) means a topcoat system composed of a colored basecoat,

a semi-transparent midcoat, and a final transparent 

clearcoat. For compliance purposes, the VOC content of 

three-stage coating systems shall meet the emission 

limitation for topcoats in Table 7.18(28)(c), and is 

calculated according to the following formula:

VOC T 3-stage = (VOC bc + VOC mc + VOC cc)

 ________________________

 4

Where:

VOC T3-stage is the weighted average of the VOC 

content, as applied, in the basecoat, midcoat, and clearcoat 

system.

VOC bc is the VOC content, as applied, of any given 

basecoat.

VOC mc is the VOC content, as applied, of any given 

midcoat.

2VOC cc is twice the VOC content, as applied, of any 

given clearcoat.

Touch-up 

Coating

7.18 means a coating applied by brush, airbrush, or nonrefillable aerosol can of no more than eight ounces to cover 

minor surface damage and imperfections.

Two-stage 

Topcoat

7.18(28) means a basecoat/clearcoat system composed of a colored 

basecoat and a transparent final coat. For compliance 

purposes, the VOC content of basecoat/clearcoat

systems shall meet the emission limitation for two-stage 

topcoats in Table 7.18(28)(c), and shall be calculated 

according to the following formula:

VOC T bc/cc = VOC bc + 2 VOC cc

 _______________

 3

Where:

VOC T bc/cc is the weighted average of the VOC content, 

as applied, in the basecoat (bc) and clearcoat (cc) system.

VOC bc is the VOC content, as applied, of any given 
basecoat.

2VOC cc is twice the VOC content, as applied, of any 

given clearcoat.

Underbody 

Coating 

7.18 means a coating designed for protection and sound 

deadening that is typically applied to the wheel wells and 

underbody of an automobile.

Uniform Finish 

Blender

7.18 means a coating designed to blend a repaired topcoat into 

an existing topcoat.

VOC Composite 

Partial Pressure

7.03, 7.18, 7.26 means the sum of the partial pressures of the compounds 

defined as VOC. VOC Composite Partial Pressure is 

calculated as follows:

Where:

Wi = Weight of the "i"th VOC compound, in grams

Ww = Weight of water, in grams

We = Weight of exempt compounds, in grams

Mwi = Molecular weight of the "i"th VOC compound, in 

g-mole

Mww = Molecular weight of water, in g-mole

Mwe = Molecular weight of exempt compound, in g-mole

PPc = VOC composite partial pressure, in mm Hg

VPi = Vapor pressure of the "i"th compound, in mm Hg

n = The number of VOC compounds

Water Hold-out 

Coating

Definitions only means a coating applied to the interior cavity areas of 

doors, quarter panels, and rocker panels for the purpose of 

corrosion resistance to prolonged water exposure.

Weld-through 

Primer

Definitions only means a primer that is applied to an area before welding is

performed, and that provides corrosion resistance to the 

surface after welding has been performed.