STATE OF RHODE ISLAND AND PROVIDENCE PLANTATIONS

DEPARTMENT OF ENVIRONMENTAL MANAGEMENT

OFFICE OF AIR RESOURCES

RHODE ISLAND AIR POLLUTION CONTROL 

GENERAL DEFINITIONS REGULATION

Effective: 19 July 2007

Last Amended 9 October 2008

AUTHORITY: These regulations are authorized pursuant to R.I. Gen. Laws § 42-

17.1-2(s) and 23-23, as amended, and have been promulgated pursuant to the 

procedures set forth in the R.I. Administrative Procedures Act, R.I. Gen. Laws Chapter 

42-35.
Page 1 of 11

STATE OF RHODE ISLAND AND PROVIDENCE PLANTATIONS

DEPARTMENT OF ENVIRONMENTAL MANAGEMENT

OFFICE OF AIR RESOURCES

AIR POLLUTION CONTROL GENERAL DEFINITIONS REGULATION

Applicability

Unless otherwise expressly defined by an individual Air Pollution Control Regulation, the terms,

definitions and unit of measure abbreviations contained herein shall be generally applicable to all 

Rhode Island Air Pollution Control Regulations adopted or amended at the same time as or after 

the adoption of these definitions.

Definitions

"Act" or "Clean Air Act" or “CAA” means the Federal Clean Air Act, as amended 42 U.S.C. 

7401, et seq.

"Actual heat input" means the gross heat release potential based upon the actual BTU content 

of the fossil fuel being burned and the rate at which it is burned.

"Administrator" means the Administrator of the United States Environmental

Protection Agency or the Administrator's duly authorized representative.

“Aerodynamic downwash” means the rapid descent of a plume to ground level with little dilution 

and dispersion due to alteration of background air flow characteristics caused by the presence of 

buildings or other obstacles in the vicinity of the emission point.

"Air contaminant" means soot, cinders, ashes, any dust, fumes, gas, mist, smoke, vapor, odor, 

toxic or radioactive material, particulate matter, or any combination of these.

"Air pollution" means the presence in the outdoor atmosphere of one or more air contaminants 

in sufficient quantities which, either alone or in connection with other emissions, by reason of 

their concentration and duration, may be injurious to human, plant or animal life, or cause 

damage to property or which unreasonably interferes with the enjoyment of life and property.

"Air pollution control system" means a system, device or equipment designed and installed 

primarily for the purpose of reducing or eliminating the emission of air contaminants to the 

atmosphere.

"Best available control technology" or "BACT" means an emissions limitation (including a 

visible emissions standard) based on the maximum degree of reduction for each air pollutant 

which would be emitted from any proposed stationary source or modification which the 

Director, on a case-by-case basis, taking into account energy, environmental and economic 

impacts and other costs, determines is achievable for such stationary source or modification 

through application of production processes or available methods, systems and techniques, 
Page 2 of 11

including fuel cleaning, clean fuels, or treatment or innovative fuel combustion techniques for 

control of such pollutant. In no event shall application of best available control technology

result in emissions of any pollutant which would exceed the emissions allowed by any 

applicable state or federal air pollution control rule or regulation. If the Director determines 

that technological or economic limitations on the application of measurement methodology to a 

particular emissions unit would make the imposition of air emissions standards infeasible, a 

design, equipment, work practice, operational standard or combination thereof, may be 

prescribed instead to satisfy the requirement of best available control technology. Such 

standard shall to the degree possible set forth the emission reduction achievable by

implementation of such design, equipment, work practice or operation and shall provide for 

compliance by means which achieve equivalent results.

“Biodiesel” means a fuel for diesel engines derived from natural oils, such as soybean oils, and 

which meets the American Society for Testing and Materials specifications of ASTM D 6751

and is registered with the US EPA as a fuel and a fuel additive under Section 211(b) of the 

Clean Air Act .

“CFR” means the Code of Federal Regulations.

"Cold Cleaning" means an organic solvent cleaning process which cleans and removes 

contaminants or water from surfaces by spraying, brushing, flushing, immersing, or drying parts. 

Cleaning machines that use heated, nonboiling solvent to clean the parts are classified as cold 

cleaning machines. Wipe cleaning is not included in this definition.

"Department" means the Rhode Island Department of Environmental Management.

"Director" means the Director of the Rhode Island Department of Environmental Management 

or any subordinate or subordinates to whom he or she has delegated the powers and duties 

vested in him or her by Title 23, Chapter 23, Section 5 of the General Laws of Rhode Island.

"Distillate Oil" means fuel oil that complies with the specifications for fuel oil numbers 1 or 2, 

as defined by the American Society for Testing and Materials in ASTM D396-78, "Standard 

Specification for Fuel Oils".

“Division” means the Rhode Island Department of Environmental Management’s Office of Air 

Resources or its predecessor agencies, the Division of Air Resources and the Division of Air 

and Hazardous Materials.

"Emissions unit" means any part of a stationary source which emits or would have the potential 

to emit any air pollutant (including fugitive emissions). This term is not meant to alter or 

affect the definition of the term "unit" for purposes of Title IV of the Act.

"Enforceable document" means a major or minor source permit issued pursuant to the 

requirements of Air Pollution Control Regulation No. 9, an operating permit or emissions cap 

issued pursuant to the requirements of Air Pollution Control Regulation No. 29, an air toxics 

operating permit issued pursuant to the requirements of Air Pollution Control Regulation No. 22, 

a consent agreement or an approval issued pursuant to the requirements of Air Pollution Control 

Regulation Nos. 15, 19, 21, 26, 27, 30 or 35.
Page 3 of 11

"EPA" means the United States Environmental Protection Agency.

"Facility" or "stationary source" means all air pollutant-emitting activities which belong to 

the same industrial grouping, are located on one or more contiguous or adjacent properties, and 

are under the control of the same person (or persons under common control). Pollutantemitting activities shall be considered as part of the same industrial grouping if they belong to 

the same "major group" (i.e. which have the same two-digit code) as described in the Standard 

Industrial Classification Manual, 1987. A facility or stationary source may consist of one or 

more emissions units. A facility or stationary source does not include emissions resulting 

directly from an internal combustion engine for transportation purposes, emissions from a 

nonroad engine or the activities of any vessel.

"Federally Enforceable" means all limitations and conditions which are enforceable by the 

Administrator of the U.S. Environmental Protection Agency 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 Categories), requirements 

within the State Implementation Plan, those requirements in operating permits issued pursuant to 

Air Pollution Control Regulation No. 29 or 40 CFR Part 71 (except those listed as "Not Federally

Enforceable"), those requirements in major or minor source permits issued pursuant to Air 

Pollution Control Regulation No. 9, to the extent the regulation is a part of the State 

Implementation Plan and those requirements in emissions caps issued pursuant to Air Pollution 

Control Regulation No. 29.

"Fossil fuel" means natural gas, petroleum, coal and any form of solid, liquid or gaseous fuel 

derived from such materials for the purpose of creating useful heat.

"Fossil fuel fired steam or hot water generating unit" means a furnace or boiler used in the 

process of burning fossil fuel for the purpose of producing steam or hot water by heat transfer.

"Fuel oil" means any virgin distillate oil, virgin residual oil, biodiesel or a blend of these.

"Fugitive emissions" means those emissions which could not reasonably pass through a stack, 

chimney, vent or other functionally equivalent opening.

"Good engineering practice" or “GEP” means, with respect to stack heights, the height 

necessary to insure that emissions from the stack do not result in excessive concentrations of 

any air pollutant in the immediate vicinity of the source as a result of aerodynamic downwash, 

eddies and wakes which may be created by the source itself, nearby structures or nearby terrain 

obstacles as calculated according to the Rhode Island Guideline on Air Quality Modeling

"Halogenated Organic Compound" and "HOC" means the following compounds: 

(a) CFC-11 (trichlorofluoromethane)

(b) CFC-12 (dichlorodifluoromethane)

(c) CFC-113 (1,1,1-trichloro 2,2,2-trifluoroethane)

(d) CFC-114 (1,2-dichloro 1,1,2,2-tetrafluoroethane)
Page 4 of 11

(e) CFC-115 (chloropentafluoroethane)

(f) HCFC-22 (chlorodifluoromethane)

(g) HCFC-31 (chlorofluoromethane)

(h) HCFC-123 (1,1,1-trifluoro 2,2-dichloroethane)

(i) HCFC 123a (1,2-dichloro-1,1,2-trifluoroethane)

(j) HCFC-124 (2-chloro 1,1,1,2-tetrafluoroethane)

(k) HCFC-141b (1,1-dichloro 1-fluoroethane)

(l) HCFC-142b (1-chloro 1,1-difluoroethane)

(m) HCFC-151a (1-chloro-1-fluoroethane)

(n) HCFC-225ca (3,3-dichloro-1,1,1,2,2-pentafluoropropane)

(o) HCFC-225cb (1,3-dichloro-1,1,2,2,3-pentafluoropropane)

(p) methyl chloroform (1,1,1-trichloroethane)

(q) methylene chloride (dichloromethane)

(r) perchloroethylene

"Hazardous Air Pollutant" and "HAP" means an air pollutant which has been

listed pursuant to Section 112(b) of the Clean Air Act Amendments of 1990.

"Heat input capacity" means the manufacturer’s or designer’s guaranteed maximum rate of 

heat input, whichever is greater.

"Lowest achievable emission rate" or "LAER" means, for any stationary source, the more 

stringent rate of emissions based on the following:

(1) The most stringent emission limitation which is contained in the implementation 

plan of any state 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

(2) The most stringent emission 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 emission rate for the new or modified installation 

within the stationary source.

In no event shall the application of this term permit a proposed new or modified 

stationary source to emit any pollutant in excess of the amount allowable under 

applicable new source performance standards.

"Natural gas" means a naturally occurring mixture of hydrocarbon and non hydrocarbon gases 

found in geologic formations beneath the earth's surface, of which the principal constituent is 

methane.

"Nitrogen oxides" means nitric oxide (NO), nitrogen dioxide (NO2) and any other species of 

nitrogen oxides, expressed as the molecular weight of NO2.

"Nonroad engine" means:

(a) Except as discussed in paragraph (b) of this definition, a nonroad engine is any internal 
Page 5 of 11

combustion engine:

(1) In or on a piece of equipment that is self-propelled or serves a dual purpose by

both propelling itself and performing another function (such as garden tractors, 

off-highway mobile cranes and bulldozers); or

(2) In or on a piece of equipment that is intended to be propelled while performing its 

function (such as lawnmowers and string trimmers); or

(3) That, by itself or in or on a piece of equipment, is portable or transportable, 

meaning designed to be and capable of being carried or moved from one location 

to another. Indicia of transportability include, but are not limited to, wheels, skids, 

carrying handles, dolly, trailer, or platform.

(b) An internal combustion engine is not a nonroad engine if:

(1) the engine is used to propel a motor vehicle or a vehicle used solely for 

competition, or is subject to standards promulgated under section 202 of the Act; 

or

(2) the engine is regulated by a federal New Source Performance Standard 

promulgated under section 111 of the Act; or

(3) the engine otherwise included in paragraph (a) (3) of this definition remains or 

will remain at a location for more than 12 consecutive months or a shorter period 

of time for an engine located at a seasonal source. A location is any single site at a 

building, structure, facility, or installation. Any engine (or engines) that replace an 

engine at a location and that is intended to perform the same or similar function as 

the engine replaced will be included in calculating the consecutive time period. 

An engine located at a seasonal source is an engine that remains at a seasonal 

source during the full annual operating period of the seasonal source. A seasonal 

source is a stationary source that remains in a single location on a permanent basis 

(i.e., at least two years) and that operates at that single location approximately

three months (or more) each year. This paragraph does not apply to an engine 

after the engine is removed from the location.

"Opacity" means the degree to which air contaminants reduce the transmission of light and 

obscure a contrasting background.

"Organic Solvent Cleaning" means the process of cleaning contaminants or water from surfaces by 

cold cleaning or vapor cleaning using Volatile Organic Compounds (VOC) or volatile Hazardous 

Air Pollutants.

"Owner or operator" means any person who owns, leases, operates, controls or supervises any 

building, structure, facility, installation or emissions unit which directly or indirectly results or 

may result in emission of any air contaminant.

"Particulate matter" means any material, other than uncombined water, that is or has been 

airborne and exists as a liquid or solid at ambient conditions.

“Permanent total enclosure” means a permanently installed enclosure that completely

surrounds a source of emissions such that all VOC emissions are captured and contained for 
Page 6 of 11

discharge to a control device and which meets the specifications given in Method 204 or 40 

CFR Part 51, Appendix M.

"Person" means an individual, trust, firm, joint stock company, corporation (including a quasigovernmental corporation), partnership, limited liability company (LLC), association, 

syndicate, municipality, municipal or state agency, fire district, club, non-profit agency or any

subdivision, commission, department, bureau, or agency of state or federal government 

(including a quasi-governmental corporation) or of any interstate body.

"Potential to emit" or "potential emissions" means:

(a) The maximum capacity of a stationary source to emit a pollutant under its 

physical or operational design. Any physical or operational limitation on the 

capacity of a source to emit a pollutant, including air pollution control equipment 

and restrictions on the 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. 

Secondary emissions do not count in determining the potential to emit of a 

stationary source. This term does not alter or affect the use of this term for any

other purposes under the Act, or the term "capacity factor" as used in Title IV of 

the Act or the regulations promulgated thereunder.

(b) “Potential emissions” from organic solvent cleaning operations at a stationary

source are calculated as follows: 

(1) Determine the potential to emit for each individual solvent cleaning 

using the following equation.

PTEi=Hi×Wi×SAIi

Where:

 PTEi=the potential to emit for solvent cleaning machine i (kilograms 

of solvent per year).

Hi=hours of operation for solvent cleaning machine i (hours per 

year).=8760 hours per year, unless otherwise restricted by a 

Federally enforceable requirement.

Wi=the working mode uncontrolled emission rate (kilograms per square 

meter per hour).=1.95 kilograms per square meter per hour for 

batch vapor and cold cleaning machines.=1.12 kilograms per square 

meter per hour for in-line cleaning machines.

SAIi= solvent/air interface area of solvent cleaning machine i (square 

meters). Cleaning machines that do not have a solvent/air interface 

shall calculate a solvent/air interface area using the procedure in 

paragraph (2) of this section.
Page 7 of 11

(2) Cleaning machines that do not have a solvent/air interface shall 

calculate a solvent/air interface area using the following equation.

 SAI=2.20 * (Vol)0.6 

Where:

SAI=the solvent/air interface area (square meters).

Vol=the cleaning capacity of the solvent cleaning machine (cubic 

meters).

(3) Sum the PTEi for all solvent cleaning operations to obtain the total 

potential to emit for solvent cleaning operations at the facility.

"Reasonably Available Control Technology" and "RACT" means the lowest emission 

limitation that a particular piece of equipment or pollutant emitting activity is capable of 

meeting by using measures that are reasonably available in terms of technological and 

economic feasibility.

"Residual oil" means No. 4, No. 5, or No. 6 fuel oil.

"Stack" means a flue, conduit or opening to provide for the emission of the products of 

combustion and/or other air contaminants into the atmosphere.

"Secondary emissions" means emissions which occur as a result of the construction or 

operation of a major stationary source or major modification, but do not come from the major 

stationary source or major modification itself. Secondary emissions must be specific, well 

defined, quantifiable and impact the same general areas as the stationary source or 

modification. Secondary emissions include emissions from any off-site support facility which 

would not be constructed or increase its emissions except as a result of the construction or 

operation of the major stationary source or major modification. Secondary emissions do not 

include emissions from any mobile source regulated under Title II of the Clean Air Act.

"Vapor Cleaning" means an organic solvent cleaning process in which contaminants or water 

are cleaned and removed from surfaces by condensing hot solvent vapor on the colder pieces. 

This definition includes vapor degreasing and drying.

"Volatile organic compound" and "VOC" means any organic compound which participates in 

atmospheric photochemical reactions. This includes any organic compound other than the 

following compounds:

(a) acetone

(b) CFC-11 (trichlorofluoromethane)

(c) CFC-12 (dichlorodifluoromethane)

(d) CFC-113 (1,1,2-trichloro 1,2,2-trifluoroethane)

(e) CFC-114 (1,2-dichloro 1,1,2,2-tetrafluoroethane)

(f) CFC-115 (chloropentafluoroethane)
Page 8 of 11

(g) 2-(difluoromethoxymethyl)-1,1,1,2,3,3,3-heptafluoropropane 

((CF3)2CFCF2OCH3)

(h) ethane

(i) 2-(ethoxydifluoromethyl)-1,1,1,2,3,3,3-heptafluoropropane 

((CF3)2CFCF2OC2H5)

(j) HCFC-22 (chlorodifluoromethane)

(k) HCFC-31 (chlorofluoromethane)

(l) HCFC-123 (1,1,1-trifluoro 2,2-dichloroethane)

(m) HCFC 123a (1,2-dichloro-1,1,2-trifluoroethane)

(n) HCFC-124 (2-chloro 1,1,1,2-tetrafluoroethane)

(o) HCFC-141b (1,1-dichloro 1-fluoroethane)

(p) HCFC-142b (1-chloro 1,1-difluoroethane)

(q) HCFC-151a (1-chloro-1-fluoroethane)

(r) HCFC-225ca (3,3-dichloro-1,1,1,2,2-pentafluoropropane)

(s) HCFC-225cb (1,3-dichloro-1,1,2,2,3-pentafluoropropane

(t) HFC-23 (trifluoromethane)

(u) HFC-32 (difluoromethane)

(v) HFC-43-10mee (1,1,1,2,3,4,4,5,5,5-decafluoropentane)

(w) HFC-125 (pentafluoroethane)

(x) HFC-134 (1,1,2,2-tetrafluoroethane)

(y) HFC-134a (1,1,1,2-tetrafluoroethane)

(z) HFC-143a (1,1,1-trifluoroethane)

(aa) HFC-152a (1,1-difluoroethane)

(bb) HFC-161 (ethylfluoride)

(cc) HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane)

(dd) HFC-236ea (1,1,1,2,3,3-hexafluoropropane)

(ee) HFC-236fa (1,1,1,3,3,3-hexafluoropropane)

(ff) HFC-245ca (1,1,2,2,3-pentafluoropropane)

(gg) HFC-245ea (1,1,2,3,3-pentafluoropropane)

(hh) HFC-245eb (1,1,1,2,3-pentafluoropropane)

(ii) HFC-245fa (1,1,1,3,3-pentafluoropropane)

(jj) HFC-365mfc (1,1,1,3,3-pentafluorobutane)

(kk) HFE-7000 (1,1,1,2,2,3,3-heptafluoro-3-methoxypropane or n-C3F7OCH3)

(ll) HFE-7100 (1,1,1,2,2,3,3,4,4-nonafluoro-4-methoxybutane or C4F9OCH3 )

(mm) HFE-7200 (1-ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane or C4F9OC2H5) 

(nn) HFE-7300 (1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-

trifluoromethylpentane or L-14787 or C2F5CF(OCH3)CF(CF3)2 )

(oo) HFE-7500 (3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-

(trifluoromethyl) hexane)

(pp) methane 

(qq) methyl acetate

(rr) methyl chloroform (1,1,1-trichloroethane)

(ss) methyl formate (HCOOCH3)

(tt) methylene chloride (dichloromethane)

(uu) parachlorobenzotrifluoride (PCBTF)

(vv) perchloroethylene (tetrachloroethylene)

(ww) cyclic, branched, or linear completely methylated siloxanes

(xx) The perfluorocarbon compounds which fall into these classes:
Page 9 of 11

(1) Cyclic, branched, or linear, completely fluorinated alkanes;

(2) Cyclic, branched, or linear, completely fluorinated ethers with no 

unsaturations;

(3) Cyclic, branched, or linear, completely fluorinated tertiary amines 

with no unsaturations; and

(4) Sulfur containing perfluorocarbons with no unsaturations and with 

sulfur bonds only to carbon and fluorine.

These compounds have been determined to have negligible photochemical 

reactivity. For purposes of determining compliance with emission limits, VOC 

will be measured by the approved test methods. Where such a method also 

inadvertently measures compounds with negligible photochemical reactivity, as 

defined above, an owner or operator may exclude these negligible photochemical 

reactive compounds when determining compliance with an emissions standard. 

Exempt solvents will be treated as water in "pounds of VOC per gallon of coating 

minus water" calculations. Classification of methylene chloride and 

perchloroethylene as exempt compounds does not relieve the facility of the 

requirements in Air Pollution Control Regulation No. 22.

The compound t-butyl acetate is considered a VOC for purposes of all 

recordkeeping, emissions reporting, photochemical dispersion modeling and 

inventory requirements which apply to VOC and shall be uniquely identified in 

emission reports, but is not a VOC for purposes of VOC emissions limitations or 

VOC content requirements.
Page 10 of 11

Abbreviations and Symbols - Units of Measure 

Abbreviations and Symbols Definition

Btu British thermal unit

°C Degree Celsius (centigrade)

cm Centimeter

dscf Dry cubic feet at standard conditions

dscm Dry cubic meter at standard conditions

°F Degree Fahrenheit

ft Feet

g Gram

gal Gallon

gr Grain

hr Hour

kg Kilogram

lb Pound

lbs Pounds

m Meter

m

3 Cubic meter

mg Milligram (10-3gram)

mm Millimeter (10-3 meter)

ppm Parts per million

psi Pounds per square inch

tpy Tons per year

g Microgram (10-6

gram)

vol Volume

wt Weight

% Percent
Page 11 of 11

General Provisions

Purpose

The purpose of this regulation is to provide a consistent set of definitions and 

abbreviations for terms used in more than one of the Rhode Island Air Pollution Control 

Regulations.

Authority

These regulations are authorized pursuant to Rhode Island General Laws § 42-17.1-2(s) 

and 23-23, as amended, and have been promulgated pursuant to the procedures set forth 

in the Rhode Island Administrative Procedures Act, Rhode Island General Laws Chapter 

42-35.

Application

The terms and provisions of this regulation shall be liberally construed to permit the 

Department to effectuate the purposes of state law, goals and policies.

Severability

If any provision of this regulation or the application thereof to any person or 

circumstance, is held invalid by a court of competent jurisdiction, the validity of the 

remainder of the regulation shall not be affected thereby.

Effective Date

The foregoing regulation, "Rhode Island Air Pollution Control General Definitions

Regulation", after due notice, is hereby adopted and filed with the Secretary of State this 

19th day of September, 2008 to become effective twenty (20) days thereafter, in 

accordance with the provisions of Chapters 23-23, 42-35, 42-17.1, 42-17.6, of the 

General Laws of Rhode Island of 1956, as amended.

W. Michael Sullivan, PhD., Director

Department of Environmental Management

Notice Given on: July 8, 2008

Public Hearing held: August 8, 2008

Filing Date: September 19, 2008

Effective Date: October 9, 2008