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ENVIRONMENT AND SAFETY 3

rinting is a chemically intensive

process and the pollution it pro-

duces affects the lives of mil-

lions of people. Environmental

laws have been enacted to help

create and maintain a healthy

environment for all. Laws also have been

promulgated to protect the worker. To the

printer, this means that the amount of pollu-

tants emitted from their operation must fall

within certain limitations.

Since the creation of the United States

Environmental Protection Agency (USEPA)

more than 25 years ago, numerous federal reg-

ulations to protect the air, water and land have

been enacted that affect the flexographic

printer. These regulations are based on

several federal statutes, including the Clean

Air, Toxic Substances Control, Resource

Conservation and Recovery, Comprehensive

Environmental Response, Compensation and

Liability, Clean Water, and Pollution Preven-

tion acts. In addition, the Occupational Safety

and Health Act, administered by the

Occupational Safety and Health Administra-

tion (OSHA) provides guidelines for workers’

protection.

Compliance with these regulations re-

quires the reduction of pollutants emitted

from facilities into the environment. Addi-

tional benefits from reducing pollution emis-

sions are improved working environment:

reduced indoor air pollutants, reduced han-

dling of hazardous solvents by employees,

and the appreciation by company employees

of the need to make a conscious effort to fur-

ther reduce waste generation.

Although the statutes discussed in this

chapter originate at the federal level, very

often it is the state or local environmental

regulatory agency that implements the actu-

al regulations. State/local laws can be more

restrictive in some cases.

Because of the many acronyms used in

this chapter, a referral list is provided in

Appendix A.

Introduction

n 1970, the United States Congress

found that the growth of urban areas

and industrial activities would bring

mounting dangers to public health and

welfare. To improve air quality by reduc-

ing the amounts of pollutants emitted,

the Clean Air Act was signed into law.

Perhaps the most extensive statute in

recent years to impact flexographic printers

were the Clean Air Act Amendments of 1990

(CAAA). The CAAA included new provisions

to control emissions of volatile organic com-

pounds from large and small operations. To

meet new national ambient air quality stan-

dards established by the USEPA, many facili-

ties either had to tighten controls of air pol-

lutants such as volatile organic compounds,

or reduce emissions for the first time. In

1996, the USEPA issued new rules under the

CAAA which affected wide-web flexographic

facilities, in response to the need for National

Emission Standards for Hazardous Air Pollu-

tants (NESHAP). In addition a revised New

Source Review is expected to be released in

the late 1990s.

The CAAA was intended to meet unad-

dressed or insufficiently addressed problems

such as acid rain, ground-level ozone, stratos-

pheric ozone depletion and air toxics. The

CAAA gave the USEPA the authority to set

National Ambient Air Quality Standards

(NAAQS) for six criteria pollutants: sulfur

dioxide, oxides of nitrogen, particulate mat-

ter, carbon monoxide, lead and ozone. It also

established a list of nearly 200 toxic air pollu-

tants and had provisions for fixing the upper-

atmosphere ozone layer. Once the USEPA

established a NAAQS for these compounds,

each state became responsible for developing

its own program for achieving and maintain-

ing these standards. Because of its impact on

small businesses, the CAAA also provided for

assistance programs to help them comply

with the new regulations. These amendments

also signaled a change from past pollution

control approaches by promoting pollution

prevention. Innovations in this law include

programs based on cooperation between gov-

ernment and industry, and pollution-preven-

tion incentives based on market forces.

The goal of the CAAA was to reduce air

pollution by 56 billion pounds per year.

These reductions are expected to come from

cutting emissions from major, as well as

many minor, sources. In particular, control

of ozone and air toxics have an impact on

flexographic printing facilities.

NATIONAL AMBIENT AIR QUALITY

STANDARDS FOR OZONE

Title I of the CAAA defines the NAAQS for

ozone precursors and places more than 90

urban areas with ozone problems into one of

five non-attainment classifications. A non-

attainment area is one which does not meet

the NAAQS for a particular pollutant. Once a

region has been designated as a “non-attain-

ment” area, USEPA mandates that the state

must achieve attainment by a certain date.

Areas range from the least polluted (mar-

ginal) and progress upward through moder-

ate, serious, severe and extreme.

An area is designated non-attainment when

the area fails to meet the national ambient air

quality standard, which for ozone is 0.12 parts

per million (ppm). Ground-level ozone (smog)

is produced when volatile organic compounds

ENVIRONMENT AND SAFETY 5

Clean Air Act

6 FLEXOGRAPHY: PRINCIPLES & PRACTICES

(VOCs) and oxides of nitrogen (NO

– a prod-

uct of combustion) are exposed to ultraviolet

light emitted from the sun.

Despite strong industry opposition, on

July 16, 1997 USEPA Administrator Carol

Browner signed the final rules which set

new NAAQS for ozone and particulate mat-

ter (PM). For ozone, the recommended final

standard was changed to a standard of 0.08

parts per million measured over eight hours,

with the average fourth highest concentra-

tion over a three-year period determining

whether an area is out of compliance. The

new rule sets an annual concentration of 15

micrograms per cubic meter of PM 2.5

microns or less in diameter and a 24-hour

standard of 65 micrograms per cubic meter.

The USEPA has been strongly criticized for

not complying with the Small Business

Regulatory Enforcement Fairness Act (SBRE-

FA), which requires federal agencies to follow

certain procedures in assessing the impact of

major regulations on small businesses.

USEPA explains that the rule does not estab-

lish any requirements applicable to small busi-

nesses. Yet, because of the 1997 changes in the

NAAQS, nearly double the number of counties

will be considered in ozone non-attainment.

Many more businesses will, therefore, be sub-

ject to new or additional emission controls

depending on the implementation plans devel-

oped by the states.

A single ozone transport region exists for

the northeastern United States (CT, DE, ME,

MD, MA, NH, NJ, NY, PA, RI, VT and the

District of Columbia) whereby all areas are

considered at least moderate non-attain-

ment.

REDUCING VOLATILE ORGANIC

COMPOUND EMISSIONS

Control of ozone smog has had a significant

effect on the flexographic printer. VOCs are

released from inks, solvents, coatings and

other materials. Therefore, to reduce ground

level ozone, emissions of VOCs had to be

reduced through either pollution prevention

(such as a water-based ink system) or control

technologies (such as adding oxidizers).

Control requirements for printers can be

classified as requirements that are imposed

on existing and new business or equipment.

The distinction between the two is that con-

trol requirements for existing operations are

usually not as stringent as those for new

installations. New installations are expected

to meet more stringent requirements because

of technological advances.

The Control Techniques Guidelines (CTGs)

for the graphic arts industry were published in

December 1978 and defined Reasonably

Available Control Technology (RACT) for flex-

ography. Subsequent USEPA guidance limited

the applicability of RACT requirements to

sources that emit 91 tons per year or more of

VOCs. The CAAA now require the use of

RACT for VOC sources that emit as little as 9

tons per year in extreme ozone non-attain-

ment areas. Therefore, states are now

required to establish and implement RACT for

those smaller sources as well. In some areas

of the country, such as the New York metro-

politan area, all flexographic facilities, regard-

less of the amount of VOC emissions, are

required to comply with RACT under state

law.

The USEPA has studied the economic and

technical feasibility of control options for

small (less than 100 tons per year potential

uncontrolled emissions)

flexographic print-

ing facilities. A 1992 USEPA document,

Alternative VOC Control Techniques Options

for Small Rotogravure and Flexography

Facilities, PB93-1223071, identifies capture

and control technologies and the costs associ-

ated with these technologies. Industry repre-

sentatives caution that the costs for capture

and control technologies may be severely

A potential emission is the capacity of a press operating under maximum

operational design for 24 hours a day and 365 days a year.

underestimated. Another USEPA publication,

Best Demonstrated Control Technology

Guidelines for Graphic Arts, PB91-168427,

compiles numerous case studies of flexo-

graphic facilities that have achieved VOC con-

trol efficiencies of 90% or better.

Solvent Recovery

Carbon adsorption systems work by cap-

turing organic solvents in a vapor form,

removing them from the air and then turning

them back into a liquid state, thus recovering

the solvent. After this process, the airstream

will contain minimal amounts of VOCs and

will be well within the allowable limits. The

process uses activated charcoal or carbon to

separate solvents from an airstream. When

the vapor-laden air from the dryers passes

through a bed of this carbon, the carbon sim-

ply catches and retains the solvent.

There should be two carbon beds. After

one has absorbed its limit of solvents, the

airstream shifts to a second bed while the

first is regenerated. To regenerate, the car-

bon is heated until it desorbs the solvent.

Steam is often used for this because it pro-

vides excellent heat transfer to the carbon

and because it is an inert medium for carry-

ing away the desorbed solvent. The conden-

sate that results is a mix of water and solvent.

For carbon adsorption to be technically fea-

sible, the water-solvent mixture must be sep-

arated by decantation or distillation.

Solvent mixtures that are insoluble in water

are often used in the graphic arts industry.

When the solvent can be separated readily

from the water and reused as raw material,

then the cost savings make solvent-recovery

systems a good choice.

Unfortunately, most solvents used in flexo-

graphic printing are blends of alcohols and

acetates, many of which are water-soluble. In

distillation, a liquid is boiled and the resulting

vapor is condensed. If the vapor and liquid

have different boiling points, separation of

the components results. But if the boiling

points are the same, the end product is essen-

tially inseparable and the mixture is termed

an azeotrope.

Acetate solvents’ components are known to

hydrolyze in the recovery process to acetic

acid. Any acid carried into the final product

must be neutralized.

With all the problems in trying to separate

solvents into reusable blends, carbon adsorp-

tion is not widely used by flexographic print-

ers. Those facilities that can utilize azeotropic

mixtures, such as an alcohol-acetate blend,

may use carbon adsorption systems.

Oxidation

Destroying solvents by oxidation is a

process that uses heat and oxygen to con-

vert organic, hydrocarbon solvents to car-

bon dioxide and water vapor.



HC  O

→

O  CO



heat

There are two oxidation techniques appro-

priate for compliance: thermal and catalytic

oxidation.

Thermal oxidation relies on the combina-

tion of high temperature (typically 1,350 to

1,800°F) , sufficient retention time (0.7 to 1.0

seconds) and effective gas-phase mixing to

achieve VOC destruction in the target range

of 98% to 99%. A basic thermal oxidizer air-

flow pattern is depicted in Figure

Because fuel is so expensive, virtually all

thermal oxidizers come equipped with some

capacity for heat recovery to minimize fuel

consumption. When the heat exchanger is an

integral part of the oxidizer, the incoming,

solvent-laden air is preheated by the hot

exhaust. This is known as primary heat

recovery. The closer the preheated air tem-

perature is to the final oxidation temperature,

the less fuel that is used.

There are two basic types of thermal oxi-

ENVIRONMENT AND SAFETY 7

These documents are available to the public through the National Technical

Information Service, 5285 Port Royal Road, Springfield, VA 22161 (800) 553-

6847.

8 FLEXOGRAPHY: PRINCIPLES & PRACTICES

dizers each with a different method of heat

exchange: recuperative and regenerative.

Recuperative oxidizers are distinguished by

the direct transfer of heat from the clean

exhaust to the process gases (typically via a

shell and tube style heat exchanger). Recu-

perative heat exchangers’ efficiencies typical-

ly vary from 4% to 80% depending on the

expected solvent loading conditions. The air

flow pattern through a recuperative thermal

oxidizer is illustrated in Figure

Regenerative thermal systems differ from

recuperative in that heat is transferred from

the cleaned exhaust to the process gases via a

heat exchange medium such as ceramic sad-

dles or rock. The medium is alternately heated

by the clean exhaust and cooled by lowering

the air temperature prior to discharge into the

atmosphere. Then, the medium desorbs heat

to the incoming process gases, heating the air

stream to nearly the operating control tem-

perature at which complete conversion will

occur. At least two regenerative beds are

required so that process air can be cycled back

and forth between the beds, alternately heating

and cooling the media (Figure

). Regen-

erative heat exchanger efficiency increases

where recuperative technology leaves off (i.e.,

at 80% to 95% efficiency).

Catalytic oxidation is a form of thermal oxi-

dation that uses a catalyst to lower the total

energy required to achieve the conversion

from hydrocarbon to carbon dioxide and

water vapor. Typical destruction efficiencies

range from 95% to 99%. In this form of tech-

nology, the catalyst induces oxidation at tem-

A basic thermal

oxidizer air-flow pattern.

High temperatures,

sufficient retention time

and effective gas-phase

mixing combine to

achieve VOC

destruction.

Air flow pattern through

recuperative thermal

oxidizer. In this

process, there is a

direct transfer

of heat from the clean

exhaust to the process

gases.

Regenerative heat

exchanger efficiency

increases where

recupertive technology

leaves off (i.e., at

80–95% efficiency).

A typical catalytic

oxidizer flow diagram.

Here, a catalyst is

used to lower the total

energy required to

achieve the conversion

from hydrocarbon to

carbon dioxide and

water vapor.

Burner

Combustion

Chamber

1350–1800°F

Retention Chamber

Tube and Shell

Heat Exchanger

From

Process

Exhaust to

Atmosphere

Auxiliary

Fuel

Burner

Combustion

Chamber

1350–1800°F

Primary

Heat

Exchanger

Process

Exhaust

Clean

Exhaust to

Atmosphere

Burner

Combustion

Chamber

Heat

Exchange

Media

1400–1800°F

Inlet

Column

Outlet

Column

Open OpenClosed

From Process

To Atmosphere

Heat

Exchange

Media

Burner

Bead or

Monolithic

Catalyst

temperature

rise dependent

on VOC loading

Primary Plate

Style Heat

Exchanger

550–700°F

From

Process

Exhaust to

Atmosphere

peratures ranging from 550

to 700

F, depend-

ing on the chemical make-up of the air stream.

Recently introduced catalysts, designed for

specific solvent chemistry and concentra-

tions, are being tested at inlet temperatures as

low as 450° F. Figure

illustrates a typical

catalytic oxidizer flow diagram.

Many chemicals exhibit catalytic activity.

Precious metal catalysts are available in

bead and block monolith form as well as

other geometric configurations. Base metal

catalysts such as manganese dioxide are also

used in some cases for VOC applications.

Catalysts have a normal life expectancy of

5 to 15 years, depending on operating tem-

perature conditions and the airstream chem-

istry. With respect to temperature, too little

heat at the inlet to the catalyst can result in a

build up of VOCs on the surface of the cata-

lyst, which in turn can result in damage to

both the catalyst and machinery when these

solvents finally ignite within the bed.

Continuous exposure to high-metal catalysts

can result in temperatures as high as 1,200°F.

In any case, a properly designed system will

include safeties to protect against either tem-

perature extreme.

With respect to air-stream chemistry, there

are a number of chemical substances that can

influence catalyst activity. These substances

fall under the categories of poisons and mask-

ing agents. Fast acting poisons such as lead,

mercury, arsenic, antimony, iron, tin and lead

will reduce catalyst activity at a rate depen-

dent upon the concentration and temperature,

and catalyst regeneration is often not possi-

ble. Some reversible poisons and masking

agents include sulfur, halogens, zinc, phos-

phorus and silicon. These chemicals tend to

coat the surface of the catalyst and can usual-

ly be removed with washing techniques

and/or increases in temperature. Organic and

inorganic solids (particulates) can also block

the pores of the catalyst, resulting in reduced

activity. However, these particles can normal-

ly be removed by either temporarily increas-

ing temperature or by cleaning. Finally, it

should be noted that a significant advance-

ment has been made in the development of

poison-resistant catalysts and special equip-

ment designs are available to minimize the

impact of catalyst-masking problems.

Because each source and facility is unique,

choosing the right oxidation technology for

any given application will require a thorough

analysis of applicable USEPA regulations, the

types and concentrations of VOCs generated

and the air volume being treated, as well as

the typical plant operating parameters. Some

generalizations can be made. For instance,

capital cost and operating cost are closely

tied to the air volume processed and the sol-

vent concentration within the air stream.

Therefore, airflow reductions through dryer

recirculation loops should be considered,

since this will reduce the total volume of air

processed while proportionately increasing

the solvent concentration (Figure

When multiple presses are connected to a

single oxidizer, the overall operating cost is

reduced as the unit spends much less time

idling at zero solvent load. In addition, heat

exchanger efficiency is improved due to the

higher heat transfer within the exchanger.

The majority of oxidizers being sold at this

time are for multiple press applications.

Finally, the oxidation process results in

ENVIRONMENT AND SAFETY 9

f Oxidizers can be sized

to treat the emissions

from one or more

presses with the latter

configuration providing

multiple benefits to the

flexographic printer.

Burner

Between

Color Dryers

Infiltration Air

BC Recirculation Loop

Exhaust to

Atmosphere

Exhaust

Fan

Supply

Fan

Burner

Overhead

Dryer

Infiltration Air

OH Recirculation Loop

Exhaust to

Atmosphere

Exhaust

Fan

Supply

Fan

10 FLEXOGRAPHY: PRINCIPLES & PRACTICES

the discharge of hot, clean air into the

atmosphere. Flexographic printers should

consider directing this energy back to their

process, either through a secondary heat

exchanger or thermostatically controlled

mixing boxes. Properly designed, a secon-

dary heat recovery system will often reduce

operating costs enough to provide an eco-

nomic payback on the initial investment.

Low-VOC Inks and Solvents

Emissions of VOCs from flexographic

printing can be reduced or eliminated at the

source by pollution-prevention techniques

such as converting from a solvent-based sys-

tem to a water-based or ultraviolet/electron

beam (UV/EB) cured system. Limitations are

associated with each approach and with

individual circumstances, including the type

of production, customer base, end-use and

type of ink used.

According to the CTG for flexography, in

use at the press, the allowable VOC content

in water-based ink must be 25% by volume or

less of the solvent portion. These inks, in

many states, are exempt from emissions con-

trols because the VOC content meets the def-

inition of a high-solid, waterborne ink. How-

ever, as air emission regulations have

become more strict, companies using inks

with even significantly less than 25% VOCs

are no longer exempt from further control.

Water-based inks are more commonly used

in publication and corrugated flexographic

printing. Paper is an excellent substrate for

waterborne inks. Some lower-VOC inks can

be applied to non-adsorbent substrates, such

as film or foil, by installing a corona treater

and altering the surface tension.

Today, UV-cured inks are being used in

narrow-web and a few wide-web flexograph-

ic operations. UV will continue to grow in

importance because of its advantages in

environmental areas and print quality. (See

Ink Chapter for additional information on

flexographic inks and solvents.)

TITLE V PERMITTING PROGRAM

Under Title V of the CAAA, every major

source of air pollutants, and all other

sources regulated will have to obtain a fed-

erally enforceable operating permit. This

permit program covers both major sources

of VOC emissions and major sources of

emissions of hazardous air pollutants.

The major source threshold for VOC emis-

sions is dependent on the non-attainment sta-

tus accorded a particular region. A source in a

non-attainment area that is defined as “major”

must install Reasonably Available Control

Technology (RACT) as prescribed in the local

State Implementation Plan. A major source is

defined both by the size of the source’s facili-

ty-wide emissions and the category of the non-

attainment area. For example, a facility in a

severe non-attainment area is considered

major if its potential to emit is more than 25

tons per year, while a facility in a moderate

non-attainment area is major when its poten-

tial to emit is more than 50 tons per year

(Table 1).

However, the major source threshold for

hazardous air pollutants is 10 tons of one or

25 tons of a combination of hazardous air

pollutants, regardless of where the facility is

located.

Each state permit program must contain

all of the following elements:

• requirements for permit applications;

• monitoring and reporting requirements;

a permit fee system;

Table 1

NON-ATTAINMENT

THRESHOLD

LEVEL TONS PER YR

Marginal 100

Moderate 100

Serious 50

Severe 25

Extreme 10

MAJOR SOURCES OF VOLATILE

ORGANIC COMPOUNDS

• provisions for adequate personnel and

funding to administer the program;

• authority to terminate, modify or revoke

and reissue permits;

• authority to enforce permits, permit

fees and the requirement to obtain a

permit, including civil penalties of not

less than $10,000 per day, and appropri-

ate criminal penalties;

• authority to assure that no permit will

issue if the USEPA objects to its issu-

ance in a timely manner;

• procedures to expedite the application

process;

• authority for public review of all permit

applications; and

• provisions to allow operational flexibil-

ity at the permitted facility.

The permit document itself must meet all

of the following requirements:

• be issued for a fixed term, not to exceed

five years;

• contain limits and conditions to assure

compliance;

• include a schedule of compliance; and

• include inspection, entry, monitoring,

compliance, certification and reporting

requirements to assure compliance.

A state permitting authority may opt to

issue general permits for groups of similar

non-major sources. Under this approach,

each individual source would still be

required to file an application. All sources

required to obtain a permit must file an

application with the state agency within 12

months after the date the USEPA approves

or develops a program applicable to that

source. The state must notify all contiguous

states and any state within 50 miles of the

source of any permitting activity and provide

an opportunity to comment. The state must

also send a copy of the permit application to

the USEPA. The USEPA has 45 days to

review and object to any permit application.

NEW SOURCE REVIEW

AND EMISSION OFFSETS

New major stationary sources of air pollu-

tion and major modifications to major station-

ary sources are required by the Clean Air Act

to obtain an air pollution permit before com-

mencing construction under the Code of

Federal Regulations (CFR), Title 40, Parts 51

and 52 (commonly written in the format 40

CFR Parts 51 and 52)

. The process is called

new source review and is required whether

the major source or modification is planned

for an area where the national ambient air

quality standards are either exceeded (non-

attainment areas) or acceptable (attainment).

Permits for sources in attainment areas are

referred to as prevention of significant deteri-

oration (PSD) permits, while sources located

in non-attainment areas are referred to as non-

attainment area (NAA) permits.

The PSD and NAA requirements are pollu-

tant-specific. For example, although a facility

may emit many air pollutants, only one or a

few may be subject to PSD or NAA permit

requirements, depending on the magnitude of

the emissions of each pollutant. Also, a source

may have to obtain both PSD and NAA per-

mits if the source is in an area designated non-

attainment for one or more of the pollutants.

The basic goal of the PSD regulations are:

• to ensure that economic growth will

occur in harmony with the preservation

of existing clean air resources;

• to protect the public health and welfare

from any adverse effect which might

occur, even at air pollution levels better

than the NAAQS; and

• to preserve, protect and enhance the air

quality in areas of special natural recre-

ational, scenic or historic value, such as

national parks and wilderness areas.

The primary provisions of the PSD regula-

ENVIRONMENT AND SAFETY 11

The Code of Federal Regulations can be purchased from the U.S. Government

Printing Office, Superintendent of Documents, (202) 512-1800.

12 FLEXOGRAPHY: PRINCIPLES & PRACTICES

tions require that the major new stationary

sources and major modifications be carefully

reviewed prior to construction to ensure

compliance with the NAAQS, the applicable

PSD air quality increments and the require-

ment to apply Best Available Control Tech-

nology (BACT) to minimize the project’s

emissions of air pollutants.

A major new source or major modification

that would be located in an area designated

as non-attainment and subject to an NAA

permit must meet stringent conditions

designed to ensure that:

• the new source’s emissions will be con-

trolled to the greatest extent possible;

• more-than-equivalent offsetting emis-

sions reductions will be obtained from

existing sources; and

• there will be progress toward achieving

NAAQS.

If a company wants to expand or change a

production process or otherwise increase its

output of a criteria air pollutant, an offset (a

reduction of the criteria pollutant by an

amount somewhat greater than the planned

increase) must be obtained somewhere else,

so that permit requirements are met and the

non-attainment area keeps moving toward

attainment (Table 2). The company must

also install tight pollution controls. An

increase in a criteria pollutant can be offset

with a reduction of the pollutant from some

other stack at the same plant or at another

plant owned by the same or some other com-

pany in the non-attainment area. Since total

pollution will continue to go down, trading

offsets among companies is allowed.

The preconstruction review requirements

for major new sources or major modifications

locating in areas designated non-attainment

differ from PSD requirements. The emission

control equipment for non-attainment areas,

lowest achievable emission rate, is defined dif-

ferently than Best Available Control Tech-

nology (BACT) emission control requirement.

The source must obtain any required emission

reductions (offsets) of the non-attainment pol-

lutant from other sources which impact the

same area as the proposed source. The appli-

cant must certify that all other sources owned

by the applicant in the state are complying

with all applicable requirements of the CAAA,

including all applicable requirements in the

State Implementation Plan. Such sources,

impacting visibility in special areas, must be

reviewed by the Federal Land Manager.

The 1997 revision to New Source Review

requirements provides industry with greater

flexibility, reduces time delays in issuing per-

mits and creates incentives for use of innov-

ative technologies. The reform reduces the

regulatory burden on industry, while still

ensuring sound environmental protection.

New Source Review ensures that industrial

expansion occurs in harmony with environ-

mental protection. New Source Review

requires large industrial facilities to obtain

permits to either build new facilities or signif-

icantly increase emissions at existing ones.

Non-attainment New Source Review applies

to large facilities in areas of the country that

have air pollution levels that exceed the

national ambient air quality standards set for

a number of air pollutants, including ground

level ozone (smog).

The PSD component of New Source

Review applies to new or changed large facil-

ities in areas of the country that have clean air

and meet air quality standards for the air pol-

Table 2

NON-ATTAINMENT THRESHOLD NEW SOURCE

LEVEL TONS PER YR OFFSET

Marginal 100 1.10 to 1

Moderate 100 1.15 to 1

Serious 50 1.30 to 1

Severe 25 1.30 to 1

Extreme 10 1.50 to 1

EMISSION OFFSET RATIOS FOR

VARIOUS NON-ATTAINMENT AREAS

lutants to be emitted by a proposed source.

Many states have New Source Review pro-

grams in place and have already implemented

most of those provisions in the CAAA.

HAZARDOUS AIR POLLUTANTS

Air toxics or hazardous air pollutants

(HAPs) include chemicals that may cause

serious health problems, such as birth

defects and gene mutations. Under Section

112 of the CAAA, nearly 200 chemicals were

listed as toxic air pollutants, and according

to USEPA, about 30 are used in the printing

industry (Table 3). These chemicals are man-

aged under the National Emission Standards

for Hazardous Air Pollutants (NESHAP) reg-

ulations. Toxic air polluters are identified as

major (large) or area (small) sources.

Of those HAPs listed above, the following

are sometimes used in the flexographic

industry:

• Methanol: As a denaturant for ethanol

(isopropanol is an alternate denaturant

for ethanol).

• Toluene: Used in small amounts in ink

formulas to keep printing clean (tolu-

ene is being replaced by a variety of

other slow solvents).

• Hexane: Used in small amounts as a

cleaning agent, but being replaced.

• Ethylene glycol: Used in small amounts

in some water-based inks, but being

replaced.

• Methyl ethyl ketone: Small amounts used

in UV curing tests. Found in coatings

and adhesives.

On July 16, 1992, USEPA published a list of

source categories that emit one or more

HAPs. For listed categories of “major”

sources (those that have the potential to

emit 10 tons per year or more of a listed haz-

ardous pollutant, or 25 tons per year or more

of a combination of hazardous pollutants),

the CAAA requires USEPA to develop stan-

dards that will require the application of

stringent air pollution controls, known as

maximum achievable control technology

(MACT). This emission level is considered

separate from emissions of VOCs, and is an

entirely different program area. The previ-

ous discussion on ozone non-attainment

does not apply to hazardous air pollutants.

USEPA’s published list of industry groups

(known as “source categories”) to be regu-

lated includes major sources in the printing

and publishing industry, including publica-

tion rotogravure printers, package-product

rotogravure and wide-web flexographic

printers (greater than 18" web width).

In a NESHAP regulation, all technology-

based emission standards must achieve the

maximum degree of emission reduction

deemed achievable by the USEPA for new or

existing sources. When setting these stan-

dards, the cost of achieving the emissions

reduction, as well as any health and environ-

mental effects and energy requirements, are

to be considered. Measures to implement

ENVIRONMENT AND SAFETY 13

Table 3

Chemicals used in the printing industry that are list-

ed as hazardous air pollutants in the CAAA.

Benzene

Cadmium compounds

Carbon tetrachloride

Chromium compounds

Cobalt compounds

Cumene

Dibutyl phthalate

Diethanolamine

Ethyl benzene

Ethylene glycol

Ethylene glycol ethers

Hexane

Hydrochloric acid

Isophorone

Lead compounds

Methanol

Methyl ethyl ketone

Methyl isobutyl ketone

Methylene chloride

Perchloroethylene

Polycyclic organic matter

Propylene oxide

Toluene

2,4-Toluene diisocyanate

1,1,1-Trichloroethane

Trichloroethylene

Vinyl chloride

Xylenes

HAZARDOUS AIR POLLUTANTS