UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103

DATE: July 14, 2011

SUBJECT: Technical Support Document – State of Maryland – Adhesives and Sealants Rule

/s/

FROM: Rose Quinto, Environmental Engineer

Office of Air Program Planning

TO: File

/s/

THRU: Cristina Fernandez, Associate Director

Office of Air Program Planning

A. BACKGROUND

On April 18, 2008, the Maryland Department of the Environment (MDE) submitted revisions to 

its State Implementation Plan SIP (Maryland SIP #08-02) to the Environmental Protection 

Agency (EPA). These SIP revisions pertain to the control of volatile organic compound (VOC) 

emissions from Polytetrafluoroethylene (PTFE) operations (amending Regulation .30 under 

COMAR 26.11.19) and from adhesives and sealants operations (adding Regulations .01 - .07 

under a new chapter, COMAR 26.11.35). On May 28, 2009, MDE submitted another revision to 

its SIP (Maryland SIP #09-01) amending Regulation .01 under COMAR 26.11.35. In addition, 

on April 23, 2010, EPA received a SIP revision (Maryland SIP #10-06) amending the control of 

VOC emissions from paint, resin, and adhesive manufacturing and adhesive and sealant 

application (Regulation .15A and C(4) under COMAR 26.11.19).

B. STATE SUBMITTAL

The SIP revisions consist of the following:

I. Amendments to COMAR 26.11.19.30 - Control of Volatile Organic Compounds from 

Chemical Production and Polytetrafluoroethylene Operations.

Minor changes were made to headings of subsections to capitalize the first letter of one or more 

words to sections 26.11.19.30B (3-2), “Inorganic Chemical Production Installation” and (5) 

“Product Condenser.” Also under section 26.11.19.30B, the definition of 

“Polytetrafluoroethylene (PTFE)” was changed to “Fluoropolymer material (FPM),” therefore, 

replacing the abbreviation “PTFE” to “FPM” throughout COMAR 26.11.19.30. In addition, 

under 26.11.19.30B, recodification of several definitions were changed to achieve uniformity in 
2

the numbering. 

Section 26.11.19.30C(2) was amended to specify that a person who owns or operates an 

installation subject to the requirements of COMAR 26.11.19.30 will not be subject to COMAR 

26.11.35 (Control of VOC Emissions from Adhesives and Sealants) provided that monthly

records are maintained which demonstrate that VOC emissions from the application of all 

adhesives, sealants, adhesive primers, and sealant primers do not exceed 400 pounds per year; 

and adhesive manufacturing do not exceed 200 pounds per year. Section 26.11.19.30C(2) is also 

subject to some minor editorial amendments which do not change its meaning and to 

accommodate the addition of the exemption from COMAR 26.11.35 into the paragraph structure 

of this section.

II. New Regulation - COMAR 26.11.35 - Control of VOC Emissions from Adhesives and 

Sealants.

Adhesives, sealants, adhesive primer, and sealant primer are used in manufacturing, packaging, 

construction, and installation of disparate materials such as metal, wood, rubber, plastic, 

ceramics, fiberglass and composites. An adhesive is any material used to bond two surfaces. A 

sealant is a material with adhesive properties that is used primarily to fill and seal durably, 

openings between two surfaces. VOC emissions result from evaporation of solvents during 

surface preparation, transfer, application, drying, and cleaning operations. The solvents are 

mostly needed to solubilize the adhesive, sealant, or primer material for application. The 

solvents prepare the surface to provide a stronger bond. In plastic pipe bonding, the solvent 

dissolves the polyvinyl chloride pipe and reacts with the pipe to form a bond. Solvents used to 

clean the surface before bonding and to clean the application equipment after bonding also 

contribute to VOC emissions. VOC emissions from adhesives and sealants are primarily from 

industrial and commercial operations such as general manufacturing, wood product 

manufacturing, upholstery shops, adhesives retailers and architectural trades, such as building 

construction, floor covering installation and roof repair.

The Ozone Transport Commission (OTC) States developed a Model Rule “OTC Model Rule For 

Adhesives and Sealants” dated 2006 which was based on the 1998 California Air Resources 

Board (CARB) reasonably available control technology (RACT) determination. This RACT 

determination applied to both the manufacture and use of adhesives, sealants, adhesive primers 

or sealant primers, in both industrial and manufacturing facilities and in the field. California Air 

Districts used this determination to develop regulations for this category. EPA addressed this 

source category with a Control Techniques Guideline (CTG) document for Miscellaneous 

Industrial Adhesives dated September 2008. This CTG was developed in response to section 

183(e) of the Clean Air Act (CAA) requirement for EPA to study and regulate consumer and 

commercial products, which is included in EPA’s Report to Congress, “Study of Volatile 

Organic Compound Emissions from Consumer and Commercial Products – Comprehensive

Emissions Inventory.” The section 183(e) miscellaneous industrial adhesives category was 

limited to adhesives and adhesive primers used in industrial and manufacturing operations and 
3

did not include products applied in the field. Therefore, the OTC Model Rule and State efforts in 

developing individual regulations preceded EPA’s CTG for this source category and were 

broader in applicability. The OTC Model Rule for adhesives and sealants and Maryland’s 

COMAR 26.11.35 provisions compared to the CTG document for Miscellaneous Industrial 

Adhesives dated September 2008 are discussed in Attachment A (see page 6 below).

COMAR 26.11.35 is a new regulation based on the OTC model rule that in turn was based on the 

CARB model rule. COMAR 26.11.35 addresses adhesive, sealants, adhesive primers and sealant 

primers that are sold in larger containers and used primarily in commercial and industrial 

applications, that includes residential applications of these products, such as carpet, flooring and 

roofing installations. COMAR 26.11.35 is also applicable to those who sell, supply, offer for 

sale or manufacture for sale in Maryland; and any adhesives, sealants, adhesive primer or sealant 

primer for use in Maryland. In addition, it is also applicable to any person who uses or applies 

any adhesive, sealant, adhesive primer or sealant primer for compensation within Maryland. 

This rule will not apply to homeowners who may be using these products for home repair and 

renovations. The VOC limits apply to those products manufactured for sale and used, on and 

after January 1, 2009 in Maryland and allows for the unlimited sell-through and use of noncompliant products manufactured before January 1, 2009 provided they contain a date or date 

code when they were manufactured. These limits are identical to those in the OTC and CARB 

model rules. 

As an alternative to the VOC limits established in Table 1 of COMAR 26.11.35, operators of 

stationary sources that use or apply adhesives, sealants, or adhesive or sealant primers have the 

option of using add-on pollution control equipment rather than complying with the Table 1 

limits. Requirements applying to air pollution control equipment include: an overall capture and 

control efficiency of at least 85 percent, by weight; the continuous monitoring of combustion 

temperature, inlet and exhaust gas temperatures and control device efficiency, depending upon 

the type of add-on controls used; and the maintenance of operation records to demonstrate 

compliance. COMAR 26.11.35 contains requirements for work practices, surface preparation 

and cleanup solvent composition. COMAR 26.11.35 also includes specific exemptions, as well 

as registration and product labeling requirements, recordkeeping requirements, and test methods 

and compliance procedures. 

EPA evaluates that COMAR 26.11.35 contains the required elements for a federally enforceable 

rule: emission limitations, compliance procedures and test methods, compliance dates and 

record keeping provisions. In comparison to the CTG, the OTC model rule and COMAR 

26.11.35 are applicable to all stationary sources including those applications that occur outside of 

the factory setting, that is, applied in the field. In addition, there are provisions that apply to the 

selling, supplying, offering for sale or manufacture for sale in Maryland of adhesives, sealants, 

adhesive primers and sealant primers along with container labeling requirements and product 

registrations. The VOC content restrictions for these products apply to both their manufacture 

and application. Stationary sources also have the option of using add-on control equipment that 

achieves 85 percent control. The OTC model rule and COMAR 26.11.35 also regulates the VOC 

content and vapor pressure of surface-preparation and clean-up solvents for which the CTG did 
4

not make recommendations for other than including work practices.

EPA recommends that when the States evaluate RACT as required by section 182(b) when 

implementing a revised 8-hour ozone standard,

1

that they review the VOC content limits for 

wood adhesives and evaluate the benefit of requiring improved methods for applying coatings 

regulated by COMAR 26.11.35.

Overall, the OTC model rule and COMAR 26.11.35: (1) Regulate the same adhesives and 

adhesive primers as the CTG with the addition of regulating sealants and sealant primers, 

(2) Apply to additional stationary sources and (3) Provide for similar exemptions as the CTG 

recommends. Therefore, COMAR 26.11.35 meets the requirement of a RACT rule for the 

miscellaneous industrial adhesives CTG category.

III. Amendments to Regulation .01 under COMAR 26.11.35.

Amendments to Regulation .01 limits the applicability of VOC standards for single-ply roof 

membrane installation and repair adhesives, single-ply roof membrane sealants, and single-ply

roof membrane adhesives primers according to the following schedules: (1) for the year 2009, 

from May 15 through September 15; (2) for the years 2010 and 2011, from May 1 through 

September 30; and (3) on and after January 1, 2012. These amendments affect manufacturers, 

suppliers, installers and users of single-ply roofing materials. These amendments provide 

additional time for training and adaption to the use of new roofing adhesive materials. Roofing 

operations are performed at a lower rate during the non-ozone season.

IV. Amendments to Regulation .15A and .15C(4) under COMAR 26.11.19. 15 “Paint, 

Resin, and Adhesive Manufacturing and Adhesive and Sealant Application.” 

The SIP revision adds “sealant” to the title of Regulation .15. The SIP revision also adds 

definitions and terms to Regulation .15A used in the substantive provisions of this SIP revision: 

sealant, sealant application, and specialty electronic systems and subsystems for defense and 

homeland security. Amendments to Regulation .15C(4) repeal the general emission standard for 

adhesives, and replacing it with the source-specific VOC RACT emission limitation for the 

application of adhesives and sealants to specialty electronic systems and subsystems for defense 

and homeland security, therefore, this source category is exempt from the requirements under 

COMAR 26.11.35. The amendments limit the discharge into the atmosphere to not more than 25 

pounds per day of VOC from adhesive and sealant application, averaged over a monthly period. 

 

1 See 75 FR 2938, January 19, 2010. In this proposed rule, March 2008, based upon reconsideration of the primary 

and secondary ozone standards, EPA proposed to set different primary and secondary standards than those 

promulgated in March 2008 to provide requisite protection of public health and welfare, respectively. 
5

D. CONCLUSIONS AND RECOMMENDED AGENCY ACTION

The amendments to Regulation .30 (COMAR 26.11.19.30) “Control of Volatile Organic 

Compounds from Chemical Production and Polytetrafluoroethylene Operations” meets the 

applicable requirements of the CAA, and the applicable EPA regulations, guidance and policy

and can be approved.

COMAR 26.11.35 “Control of VOC Emissions from Adhesives and Sealants” adopted by 

Maryland will result in the reduction of VOC emissions from the affected sources and meets the 

applicable requirements of the CAA, and the applicable EPA regulations, guidance and policy

and can be approved.

Amendments to Regulation .01 under COMAR 26.11.35, and Regulation .15A and C(4) under 

COMAR 26.11.19, will result in the reduction of VOC emissions from the affected sources and 

meets the applicable requirements of the CAA, and the applicable EPA regulations, guidance and 

policy and can be approved.

EPA’s approval of the SIP revisions is recommended. 
6

ATTACHMENT A

OTC Model Rule for Adhesives and Sealants and Maryland’s COMAR 26.11.35

Provisions Compared to the Control Technique Guidelines for Miscellaneous Industrial 

Adhesives, September 2008

OTC Model Rule

The Ozone Transport Commission (OTC) developed a model rule as part of a regional effort to 

attain and maintain the eight-hour ozone standard and reduce eight-hour ozone levels. States 

opting to promulgate rules based on this model rule will utilize State-specific administrative 

requirements and procedures. Maryland’s adopted COMAR 26.11.35 “Control of Volatile 

Organic Compound (VOC) Emissions from Adhesives and Sealants” is based on the OTC model 

rule.

A reasonably available control technology (RACT) determination prepared by the California Air 

Resources Board (CARB) in 1998 forms the basis of the OTC model rule. In the years 1998-

2001, the provisions of the CARB determination were adopted in regulatory form in various air 

pollution control districts in California including the Bay Area, Ventura County, Sacramento

Metropolitan and San Joaquin Valley.

The provisions of this model rule limit emissions of VOCs from adhesives, sealants, adhesive 

primers and sealant primers. The model rule achieves VOC reductions through two basic 

components: (1) sale and manufacture restrictions that limit the VOC content of specified 

adhesives, sealants, adhesive primers and sealant primers sold in the state; and (2) use 

restrictions that apply primarily to commercial and industrial applications. By reducing the 

availability of higher VOC content adhesives and sealants within the State, the sales prohibition 

is also intended to address adhesive and sealant usage at area sources. Emissions from 

residential use of regulated products are addressed through the sales restrictions and simple use 

provisions. 

The associated emissions reductions will be used as part of the State’s plan to attain and maintain 

the 8-hour ozone national ambient air quality standard (NAAQS).

Control Techniques Guideline

The Environmental Protection Agency (EPA) addressed a portion of this category, adhesives and 

adhesive primers, in a Control Techniques Guideline (CTG) document - “Control Techniques 

Guidelines for Miscellaneous Industrial Adhesive, EPA-453/R-08-005” in September 2008. (See 

Docket number EPA-HQ-OAR-2008-0460.)

“This CTG is intended to provide State and local air pollution control authorities 
7

information that should assist them in determining RACT for VOCs from miscellaneous 

industrial adhesive application processes. In developing this CTG, EPA, among other 

things, evaluated the sources of VOC emissions from miscellaneous industrial adhesives 

application processes and the available control approaches for addressing these 

emissions, including the costs of such approaches. Based on available information and 

data, EPA provides recommendations for RACT for miscellaneous industrial adhesives. 

States can use the recommendations in this CTG to inform their own determination as to 

what constitutes RACT for VOCs for miscellaneous industrial adhesive application 

processes in their particular nonattainment areas. The information contained in this 

document is provided only as guidance. This guidance does not change, or substitute for, 

requirements specified in applicable sections of the CAA or EPA’s regulations; nor is it a 

regulation itself. This document does not impose any legally binding requirements on 

any entity. It provides only recommendations for State and local air pollution control 

agencies to consider in determining RACT. State and local pollution control agencies are 

free to implement other technically-sound approaches that are consistent with the CAA 

and EPA’s implementing regulations” (CTG page 1). 

“When State and local pollution control agencies develop RACT rules, they may elect to 

adopt control approaches that differ from those described in this document and/or 

promulgate applicability criteria that differ from those recommended here [in this CTG].” 

(CTG page 3).

EPA issued the CTG pursuant to the authority and to meet a requirement set by section 183(e) of 

the CAA. Section 183(e) directed EPA to list for regulation, those categories of products that 

account for at least 80 percent of the VOC emissions from consumer and commercial products in 

ozone nonattainment areas, and to schedule those categories for regulation in four groups. 

Section 183(e)(3)(C) further provides that we may issue a CTG in lieu of a national regulation 

for a product category where we determine that the CTG will be “substantially as effective as 

regulations” in reducing emissions of VOC in ozone nonattainment areas. See for example, 64 

FR 13422, March 18, 1999. EPA has revised the list several times. See 70 FR 69759, 

November 17, 2005; 64 FR 13422, March 18, 1999; and most recently, 71 FR 28320, May 16, 

2006.

Under section 183(e), a regulation for consumer or commercial products is limited to measures 

applicable to manufacturers, processors, distributors, or importers of the solvents, materials, or 

products supplied to the consumer or industry. Section 183(e) does not authorize EPA to issue 

national regulations that would directly regulate end-users of these products. By contrast, CTG 

are guidance documents that recommend RACT measures that States can adopt and apply to the 

end-users of products. See 73 FR 58481 at 58483, October 7, 2008. However, section 183(e) 

does not impose the same restrictions upon States, upon regulation of end-users and 

manufacturers, processors, distributors, or importers. Therefore, a State can regulate 

manufacturers, processors, distributors, or importers and end-users of a product category for 

which EPA has issued a CTG. 
8

I. Applicability

(1) The scope of the CTG is focused on industrial adhesive application processes at facilities, 

i.e., stationary sources. The limits and requirements apply to facilities where the total actual 

VOC emissions from all miscellaneous industrial adhesive application processes, including 

related cleaning activities, at that facility are equal to or exceed 6.8 kg/day (15 lb/day), or an 

equivalent level such as 3 tons per 12-month rolling period, before consideration of controls. 

The OTC model rule is broader than the CTG and applies to processes below the 6.8 kg/day

recommendation. It also applies outside of stationary source facilities when the adhesives are 

applied in the field.

(2) The OTC model rule is also applicable to any person who: sells, supplies for sale, offers for 

sale or manufactures for sale any adhesive, sealant, adhesive primer or sealant primer. The CTG 

is not applicable to these people. 

II. Definitions

Generally the OTC model rule and CTG use the same terms and definitions for those terms. The 

OTC model rule contains additional definitions to address sealants and sealant primers and 

additional types of products. There are minor differences with some terms because the CTG 

focuses on the processes at a facility while the OTC model rule also incorporates prohibitions on 

selling, offering for sale and using products that can occur outside of a facility. There are some 

instances where the CTG and the OTC model rule use different terms for the same 

process/product, but these are substantively the same.

Specific examples:

There appears to be an inconsistency in the CTG with the category of tire repair and tire retread. 

Tire repair generally would not occur at a manufacturing facility, but at smaller operations in the 

field. The draft CTG used a term “tire retreading” which would be a process that occurs at a 

manufacturing facility. The OTC model rule and COMAR 26.11.35 regulate “tire retread” and 

defines the category in terms of manufacture and not the repair of a puncture. COMAR 

26.11.35’s definition is consistent with South Coast Air Quality Management District 

(SCAQMD) rule 1168’s definition of “tire tread adhesive.” The CTG was developed based upon 

SCAQMD rule 1168 and similar rules. Therefore, with regards to “tire retread” and “tire repair” 

processes, the OTC model rule and COMAR 26.11.35 are consistent with those rules upon which 

the CTG founded its recommendations.

The CTG does not distinguish between cleaning materials used for surface preparation and those 

used for cleaning application equipment, but the OTC model rule does make this distinction. 

The recommendations for roof membranes in the CTG do not extend to field applied materials, 
9

because: (1) field-applied adhesives are not part of the miscellaneous industrial adhesives 

category and are therefore not covered by this CTG, and (2) nonmembrane roof installation and 

repair adhesive, and ethylene propylene diene monomer (EPDM) described in the comments 

received on the draft CTG are field applied products and are therefore not included in the 

miscellaneous industrial adhesives category. To the extent the recommendations in the OTC 

model rule sets limits for EPDM single-ply roof membranes it makes a recommendation beyond 

those in the CTG. It appears that the inclusion of “motor vehicle glass bonding primer” in the 

CTG covers a slightly broader class of adhesives primers than “automotive glass adhesive 

primer.”

The OTC model rule includes wood in the definition of “porous material” while the CTG does 

not and has a separate limit for wood. The CTG’s recommended definition was made in the 

absence of limits for sealants and sealant primers and specifically excludes wood from being 

considered a porous material. 

III. Requirements

(1) The OTC model rule applies to any person who sells, supplies or offers for sale any 

adhesive, sealant, adhesive primer or sealant primer manufactured on or after January 1, 2009, or 

manufacture for sale any adhesive, sealant, adhesive primer or sealant primer in excess of the 

applicable VOC content limits specified in Table 1. The CTG does not apply to people who sell 

or manufacture these coatings.

(2) The OTC model rule applies to any person who uses or applies (for compensation) any 

adhesive, sealant, adhesive primer or sealant primer that has an applicable VOC content limit 

specified in Table 1 that is not otherwise exempted. The CTG only recommends application of 

the limits and requirements to facilities where the total actual VOC emissions from all 

miscellaneous industrial adhesive application processes, including related cleaning activities, at 

that facility are equal to or exceed 6.8 kg/day (15 lb/day), or an equivalent level such as 3 tons 

per 12-month rolling period, before consideration of controls. The OTC model rule covers “field 

applied adhesives” which the CTG does not cover.

(3) Both the CTG and the OTC model rule have a table of content limits for the regulated 

products. See the comparison of table limits and discussion below.

(4) The CTG did not propose recommendations for VOC content or VOC composite vapor 

pressure limits for cleaning materials. The OTC model rule and COMAR 26.11.35 contained the 

following limits for cleaning materials:

a. Limits the VOC content of the surface preparation solvent to less than 70 grams per 

liter;
10

b. Limits the VOC content of surface preparation solvent used in applying single-ply 

roofing to a composite vapor pressure, excluding water and exempt compounds, not 

exceeding 45 mm Hg at 20 degrees Celsius;

c. Limits materials containing VOCs used to remove adhesives, sealants, or adhesive or 

sealant primers from surfaces unless the composite vapor pressure of the solvent used is 

less than 45 mm Hg at 20 degrees Celsius;

d. Requires spray application equipment be cleaned in enclosed cleaning systems using 

cleaning solvents with less than or equal to 70 grams of VOC per liter of material, or by 

soaking parts in closed systems using and a solvent if the composite vapor pressure of the 

solvent, excluding water and exempt compounds, is less than or equal to 9.5 mm Hg at 20 

degrees Celsius.

(5) Both the CTG and OTC model rule provide for the use of add-on air pollution control 

equipment instead of meeting the solvent content limits. Both require that controls reduce VOC 

emissions by an overall capture and control efficiency of at least 85% by weight. The OTC 

model rule includes additional provisions to insure that the control equipment is operated 

properly.

(6) Both the CTG and OTC model rule require work practices to minimize emissions from 

cleaning operations. The CTG recommendations are more detailed while the OTC model rule is 

more general.

(7) The OTC model rule prohibitions the specification of non-complying adhesives, sealants, 

adhesive primers, sealant primers, surface preparation or clean-up solvents. 

(8) The CTG also recommends that adhesive and adhesive primers be applied using application 

methods with good transfer efficiency in conjunction with the use of low-VOC content 

adhesives. Specifically, the CTG recommends the following application methods: electrostatic 

spray, HVLP spray, flow coat, roll coat or hand application including non-spray application

methods similar to hand or mechanically powered caulking gun, brush, or direct hand 

application), roll coat, dip coat (including electrodeposition), airless spray, air-assisted airless 

spray, or other coating application method capable of achieving good transfer efficiency. (Final 

CTG, Section VI.B., page 19). The CTG recommends application methods with good transfer 

efficiencies for stationary facilities and does not make recommendations for field applied 

adhesives and sealants. The OTC model rule does not address application methods.

IV. Exemptions and Exceptions

(1) CTG and OTC model rule have similar exemptions for the following:

a. Adhesives, sealants, adhesive primers or sealant primers being tested or evaluated in 

any research and development, quality assurance or analytical laboratory. 
11

b. Cyanoacrylate adhesives.

c. Adhesives, sealants, adhesive primers or sealant primers that are sold or supplied by

the manufacturer or supplier in containers with a net volume of 16 fluid ounces or less, or 

a net weight of one pound or less, except plastic cement welding adhesives and contact 

adhesives.

d. Processes using polyester bonding putties to assemble fiberglass parts at fiberglass 

boat manufacturing facilities and at other reinforced plastic composite manufacturing 

facilities.

e. In the assembly, repair and manufacture of aerospace or undersea-based weapon 

systems.

f. Solvent welding operations used in the manufacture of medical devices.

(2) OTC model rule exemptions not in CTG:

a. Adhesives, sealants, adhesive primers and sealant primers that are subject to State 

consumer product regulation. State consumer product regulations generally regulate the 

same categories as the Federal Regulation (of 40 CFR Part 59). Under section 183(e) the 

consumer products regulated by 40 CFR Part 59 cannot be the same adhesive products 

and adhesive primers as those covered by the CTG, and, therefore this provision of the 

OTC model rule merely clarifies that here is no double regulation2.

b. Adhesives and sealants that contain less than 20 grams of VOC per liter of adhesive or 

sealant, less water and less exempt compounds, as applied. This limit is less than any 

limit recommended by the CTG.

c. Contact adhesives that are sold or supplied by the manufacturer or supplier in 

containers with a net volume of one gallon or less. Some California Air Districts have a 

similar size exemption but with additional conditions.

d. Tire repair operations, provided the label of the adhesive states "For tire repair only." 

e. Plaque laminating operations in which adhesives are used to bond clear, polyester 

acetate laminate to wood with lamination equipment installed prior to July 1, 1992. Any

person claiming exemption pursuant to this subparagraph shall record and maintain 

monthly operational records sufficient to demonstrate compliance with this exemption 

and in accordance with section (V) of this rule.

 

2 The latest listing of product categories regulated under section 183(e) of the CAA was published on May 16, 2006 

(71 FR 28320).
12

In addition, the CTG recommends that these sources be subject to the work practices 

recommendation. 

(3) The OTC model rule exempts total VOC emissions from all adhesives, sealants, adhesive 

primers and sealant primers used at a facility that are less than 200 pounds per calendar year, or 

an equivalent volume. Any person claiming exemption pursuant to this subparagraph shall 

record and maintain monthly operational records sufficient to demonstrate compliance. 

(4) The OTC model rule exempts adhesives, sealants, adhesive primers, sealant primers, cleanup 

solvents and surface preparation solvents provided the total volume of noncomplying adhesives, 

sealants, primers, cleanup and surface preparation solvents applied facility-wide does not exceed 

55 gallons per calendar year. Any person claiming exemption pursuant to this subparagraph 

shall record and maintain monthly operational records sufficient to demonstrate compliance. 

This is equivalent to 400 pound per year, while the CTG applicability starts at 6.8 kg/day (15 

lb/day) or an equivalent level such as 3 tons (6000 pound) per 12-month rolling period.

(5) The OTC model rule exempts adhesive, sealant, adhesive primer or sealant primer intended 

for shipment and use outside of OTC States or in COMAR 26.11.35.

(6) The OTC model rule exempts any adhesive, sealant, adhesive primer or sealant primer that is 

controlled by add-on air pollution control equipment. 

V. Administrative Requirements

The OTC model rule contains detailed record keeping requirements for demonstrating 

compliance with the VOC content limits and recording the key operating parameters for the 

control equipment that must be maintained for five years. Any State rule for a CTG must contain 

monitoring and recordkeeping requirements. 

VI. Compliance Procedures and Test Methods

Both the CTG and OTC model rule contain the same primary test methods and compliance 

procedures. The OTC model rule contains additional references to other relevant standard test 

methods for both solvent analysis and for determining compliance of add-on control equipment.

Any State rule for a CTG must contain test methods for determining compliance. 

VII. Container Labeling

The OTC model rule requires labeling of product container with the maximum or actual VOC 

content of the product along with information concerning thinning of the product.
13

VIII. Emission Limit Table

The table below provides an analysis of the CTG recommended VOC emission limits for general 

and specialty adhesive application processes compared to the OTC model rule VOC content 

limits for adhesives, sealants, adhesive primers sealant primers and adhesives applied to 

particular substrates. Where there is no comparable limit the column is left blank. In the CTG 

recommendation column, categories with brackets { } around them indicates there is a 

difference in a definition or provision which differs from the OTC model rule. Below the table 

are series of “Notes” which discuss some of the differences between the OTC model rule and the 

CTG and refer back to some of the California adopted rules (CARB model rule) for which the 

OTC model rule was based on. 

Both the CTG and the OTC model rule were based on the California rulemaking efforts for this 

category and the CTG also bases its recommended emission limits on the OTC model rule (see 

CTG page 16, last paragraph). The CTG also states “we consider the limits in the OTC model 

rule to be representative of what sources in nonattainment areas nationwide can achieve

technically and economically and have therefore adopted these VOC limits as our 

recommendations in the CTG.” 

OTC Model Rule CTG Recommendation

Category VOC content limit

(grams VOC per 

liter*)

Category Recommended VOC 

Emission Limit1

(g/l)

Adhesives Specialty Adhesive 

Application Processes

ABS welding 400 {Plastic Solvent Welding 

(ABS)}

400

Ceramic tile installation 130 Ceramic Tile Installation 130

Computer diskette jacket 

manufacturing

850

Contact bond [Note C] 250 {Contact Adhesive} [Note C] 250

Cove base installation 150 Cove Base Installation 150

CPVC welding 490 {Plastic Solvent Welding 

(Except ABS)}

{500}

Indoor floor covering installation 150 Floor Covering Installation 

(Indoor)

150

Metal to urethane/rubber 

molding or casting

850 Metal to Urethane/Rubber 

Molding or Casting

850

Motor Vehicle Adhesive

[Note H]

250

Motor Vehicle Weatherstrip 750
14

OTC Model Rule CTG Recommendation

Adhesive [Note H]

Multipurpose construction 200 Multipurpose Construction 200

Nonmembrane roof 

installation/repair

300

Other plastic cement welding 510 {Plastic Solvent Welding 

(Except ABS)}

{500}

Outdoor floor covering 

installation

250 Floor Covering Installation 

(Outdoor)

250

PVC welding 510 {Plastic Solvent Welding 

(Except ABS)}

{500}

Single-ply roof membrane 

installation/repair [Note G]

250 Single-Ply Roof Membrane 

Installation/Repair (Except 

EPDM)

250

Structural glazing 100 Structural Glazing 100

Thin metal laminating 780 Thin Metal Laminating 780

Tire Repair [Note A] 100

Tire retread [Note A] 100

Perimeter bonded sheet vinyl 

flooring installation

660 {Floor Covering Installation 

(Perimeter Bonded Sheet 

Vinyl)} [Note C]

660

Waterproof resorcinol glue 170 Waterproof Resorcinol Glue 170

Sheet-applied rubber installation 850 {Sheet Rubber Lining 

Installation} [Note C]

850

Sealants

Architectural 250

Marine deck 760

Nonmembrane roof 

installation/repair

300

Roadway 250

Single-ply roof membrane 450

Other 420

Adhesive Primers Adhesive Primer 

Application Processes

Automotive glass [Note G] 700
15

OTC Model Rule CTG Recommendation

Motor Vehicle Glass 

Bonding Primer [Notes B 

and G]

900

Plastic cement welding 650 {Plastic Solvent Welding 

Adhesive Primer} [Note C]

650

Single-ply roof membrane 250 Single-Ply Roof Membrane 

Adhesive Primer [Note B]

250

Traffic marking tape 150

Other [Note G] 250 Other Adhesive Primer 

[Note B]

250

Sealant Primers

Non-porous architectural 250

Porous architectural 775

Marine deck 760

Other 750

Adhesives Applied to the 

Listed Substrate

 [Notes E and H] General Adhesive 

Application Processes 2

[Note E]

Flexible vinyl [Note H] 250 Flexible vinyl 250

Fiberglass [Notes F & H] 200 

Reinforced plastic 

composite [Note F]

[Note F] 200

Metal [Note H] 30 Metal 30

Porous material (Including 

wood)

 [Note H] 120 Porous Material (Excluding 

Wood)

120

Rubber [Note H] 250 Rubber 250

Other substrates [Note H] 250 Other Substrates 250

Wood 30

* The VOC content is determined as the weight of volatile compounds, less water and exempt 

compounds as specified in Section VI of this rule.

1 Emission limits are mass of VOC per volume of adhesive or adhesive primer, excluding water and exempt 

compounds.

2 If an adhesive is used to bond dissimilar substrates together, then the applicable substrate category with the highest 

VOC emission limit is recommended as the limit for such application. The analogous provision in the OTC Model 

Rule is found in Section III. (3) of that rule.

Notes: 

A. The CTG is inconsistent with the State rules cited in Appendix B in that none of these 

rules set a limit for “tire repair” adhesives (as that term is defined in each of these rules) but 
16

rather set a limit for “tire retread(ing) adhesives” which is the same as the 100 g VOC/liter limit 

in the OTC model rule (which is as expected since this rule is based upon one or more of the 

California rules). 

B. The CTG has the words “Adhesive Primer” in its table whereas in the OTC model 

rule this is to be understood from the sub-heading. 

C. The CTG and OTC Model Rule use slightly different terms to cover the same 

processes or products. 

- The CTG uses the term “Floor Covering Installation (Perimeter Bonded Sheet Vinyl)” to 

cover what the OTC Model Rule covers as “Perimeter Bonded Sheet Vinyl.” 

- The term “Sheet-applied rubber installation” in the OTC Model Rule means the same 

thing as “Sheet Rubber Lining Installation” in the CTG.

- “Contact bond” adhesive and ““Contact adhesive” would appear to be the same thing. 

Both the OTC Model Rule and the CTG definitions for “Contact bond adhesive” are the 

same and both use “Contact adhesive” within this definition to refine its scope.

- The OTC Model Rule uses “Plastic Cement Welding Adhesive Primer” where the CTG 

uses “Plastic Solvent Welding Adhesive Primer” for the same product/process.

D. The inclusion of the category “plastic adhesive primer” in the Draft CTG was an 

error. This category has been removed from the final CTG.

E. The OTC model rule uses the term “Adhesives Applied to the Listed Substrate” where 

the CTG uses the term “General Adhesive Application Processes.” 

F. The CTG covers more materials with the broader definition of “Reinforced plastic 

composite” than the OTC model rule if the latter considers “fiberglass” to means fine glass fibers 

in a plastic resin. But the OTC rule defines “fiberglass” as a material consisting of extremely 

fine glass fibers; thus, a “fiberglass substrate adhesive” could be interpreted as meaning an 

adhesives used to bond glass fibers together or to another listed substrate. The OTC definition is 

consistent with several California AQMD rules such as SCAQMD Rule 1168, Sacramento 

Metropolitan AQMD Rule 460; other California AQMDs do not define “fiberglass” – e.g., San 

Diego County AQMD rule 67.21; however, Ventura County AQMD Rule 74-20 defines 

fiberglass as “...any fiber reinforced plastic (FRP) surface that has fiber material set in a binding 

substance of plastic resins” which appears to be the functional equivalent of the final CTG’s 

definition of “Reinforced plastic composite.”

G. To the extent the OTC Model Rule limit for “Automotive glass adhesive primers” and 

the recommendation in the final CTG for “Motor Vehicle Glass Bonding Primer” both cover the 

same material or process the recommendation in the OTC model rule is more stringent. To the 
17

extent that the definition of recommendation in the final CTG for “Motor Vehicle Glass Bonding 

Primer” covers more processes or operations the recommendation in the final CTG would be 

more stringent except the OTC model rule may cover any additional products under the other 

primer category. The recommendation in the OTC model rule for applying an “Automotive 

glass adhesive primer” to automotive glass is clearly more stringent. However, recommendation 

in the CTG for “Motor Vehicle Glass Bonding Primer” would cover primers applied to “body 

openings” prior to the application of glass bonding adhesives or the installation of adhesive 

bonded glass. Body openings may include substrates such as bare metal or plastic as well as the 

glass itself. To the extent the limit for “other adhesive primers” covers “Motor Vehicle Glass 

Bonding Primers” other than those when applied to automotive glass, the recommendation in the 

OTC model rule would seem to be more stringent.

H. Whether the recommendation in the OTC model rule is equal to, less stringent or 

more stringent than the recommendations in the CTG for these categories depends upon whether 

the OTC model rule covers these applications under the “Adhesives Applied to the Listed 

Substrate” and which limit applies. The applicable limit depends upon what substrates are 

involved. The OTC model rule allows compliance to the higher of two applicable substrate 

limits when bonding dissimilar substrates. In no case is an OTC limit for any “listed substrate” 

greater than that recommended in the CTG for “Motor Vehicle Adhesives” and “Motor Vehicle 

Weatherstrip Adhesives;”as such, the OTC model rule would seem to be more stringent. 

I. The OTC Model rule applies a limit to ethylene propylene diene monomer (EPDM) 

roof membranes. The CTG excluded EPDM membranes from the VOC recommendation for 

“Single-Ply Roof Membrane Installation/Repair” specialty adhesives based upon comment that 

such limits could not be met for field applied EPDM. Some OTC States have limited the CTG 

recommendation for May 1 to September 30 for two years and then set the limit year-round after 

that.

IX. Conclusions

The OTC Model rule and specifically, COMAR 26.11.35, for adhesives and sealants and the 

2008 CTG for miscellaneous industrial adhesives were developed to address the emissions of 

VOC from adhesives. The CTG was developed with a restriction that it only applies to larger 

sources with manufacturing operations that use these types of products. Whereas, the OTC 

model rule includes these sources as well as smaller operations, operations performed in the field 

and also regulation of the manufacture, distribution and sale of the products themselves. The 

OTC model rule also regulates sealants and sealant primers which are not included in the CTG 

because they were not categorized with miscellaneous industrial adhesives under section 183(e).

The CTG and the OTC model rule exemption categories are very similar though some 

differences exist, but the CTG recommends that exempted operations be subject to work 

practices. The OTC model rule does not include work practices. The work practices benefit 

cannot be quantified and in these instances, generally apply to lower usage source categories so 
18

very few emission reductions are missed by not including these requirements. The OTC model 

rule contains an exemption provision which is in fact a de facto applicability level that equates to 

400 pounds per year of VOC emissions which is less than the CTG’s yearly limit of 3 tons per 

year. The model rule’s 400 pounds per year exclusion includes emissions from sealants and 

sealant primers and not just adhesives and their primers and therefore sets a lower numerical 

limit and includes more emissions subject to the applicability threshold. 

The CTG recommended work practices for cleaning materials included more activities than the 

OTC model rule. However, some of the OTC clean-up provisions are more stringent, i.e.

limiting clean-up solvent vapor pressure and VOC content, and cleaning of spray application 

equipment; overall, the OTC requirements in terms of emission reductions are at least equivalent 

to or result in more emission reductions than the CTG.

The CTG makes recommendations for application methods be used in conjunction with the use 

of low-VOC content adhesives and adhesive primers to improve transfer efficiency. The OTC 

rule does not specify application methods. The CTG recommendation goes to “stationary

sources” above a cut-off level only. The OTC model rule was based on the CARB 1998 RACT 

and best available retrofit control technology (BARCT) determination for adhesives and sealants 

which did not include the requirement for application methods. Maryland’s proposed 

rulemaking states that 96 percent of the adhesive and sealant VOC emissions in the OTC States 

fall into the area source category. This would appear to limit the benefit from improved transfer 

equipment. However, EPA recommends that when the States evaluate RACT as required by 

section 182(b) when implementing a revised 8 hour ozone standard3, that they review and 

evaluate the benefit of requiring improved methods for applying coatings regulated by the OTC 

model rule and specifically, COMAR 26.11.35.

Overall, the CTG and the OTC model rule emission limits are similar with the exception of 

general adhesive for wood applications. The CTG recommends a 30 g/liter limit for the wood 

substrate category whereas the OTC model rule covers wood under the “porous material” 

substrate category with a limit of 120 g/liter. It is recommended that when the States evaluate 

RACT as required by section 182 (b) when implementing a revised 8-hour ozone standard, that 

they review the VOC content limit for wood adhesives.

The CTG does not require State rules to match the line-by-line, item-by-item because it stated: 

“When State and local pollution control agencies develop RACT rules; they may elect to adopt 

control approaches that differ from those described in this document and/or promulgate 

applicability criteria that differ from those recommended here.” (CTG page 3.) For the most 

part the OTC Model rule and specifically, COMAR 26.11.35, match the CTG’s 

recommendations item by item. The OTC Model rule and specifically, COMAR 26.11.35, 

requires the emission limitations apply to a wider universe of sources and to manufacturers and 

distributors of adhesives and primers. The OTC Model rule and specifically, COMAR 26.11.35, 

 

3 See 75 FR 2938, January 19, 2010; In this proposed rule, March 2008, based upon reconsideration of the 

primary and secondary ozone standards, EPA proposed to set different primary and secondary standards than those 

promulgated in March 2008 to provide requisite protection of public health and welfare, respectively. 
19

sets standards for clean-up and surface preparation solvents in lieu of the application methods 

and all work practice recommendations in the CTG. Overall, EPA can conclude the OTC Model 

rule and specifically, COMAR 26.11.35, meets the requirement for RACT in this source 

category.