FACT SHEET

FINAL AMENDMENTS TO THE AIR TOXICS STANDARDS FOR
MINERAL WOOL PRODUCTION AND WOOL FIBERGLASS MANUFACTURING

ACTION

•	On June 25, 2015, the Environmental Protection Agency (EPA) issued final risk and technology
review (RTR) amendments to the emission standards regulating mineral wool and wool fiberglass
facilities and a new air toxics standard for area sources in the wool fiberglass manufacturing
industry. These three rules will further reduce emissions of toxic air pollutants, also known as
hazardous air pollutants (HAP) or air toxics, which are known or suspected to cause cancer and other
serious health and environmental effects.

•	Industrial facilities that have the potential to emit at least 10 tons per year of a single toxic air
pollutant or 25 tons per year of any combination of toxic air pollutants are "major" sources.

Facilities that emit less than these amounts are called "area" sources.

•	EPA issued the air toxics standards for major sources in the mineral wool production and the wool
fiberglass manufacturing industries separately in June 1999. EPA proposed action on its review of
the remaining health risks and updated technologies for these industrial categories together in
November 2011.

•	Products made from mineral wool are generally used in high population density buildings for
insulation, fire proofing and noise attenuation. The mineral wool air toxics standards currently apply
to eight facilities, all of which are major sources.

•	Wool fiberglass products are mostly used for residential insulation, with two plants also operating a
pipe insulation line. There are a total of 30 sources in the wool fiberglass industry. The air toxics
standards currently apply to 10 major source facilities. The area source rule applies to the remaining
20 wool fiberglass facilities.

•	EPA supplemented its November 2011 proposal for wool fiberglass major sources by proposing
first-time standards for wool fiberglass area sources in April 2013.

•	In November 2014, EPA issued a second supplemental proposal to revise emission limits based on a
new approach to maximum achievable control technology (MACT) floor calculations with limited
datasets. EPA also explained the use of the upper prediction limit in setting emission limits and
issued a few clarifications and corrections to the previous proposals.

Final Wool Fiberglass Area Source Rule

• Most wool fiberglass plants have become area sources by eliminating or reducing
phenol/formaldehyde emissions from the binding processes in their wool fiberglass
manufacturing lines. Reducing these emissions decreases their overall air toxics emissions and
changes their applicability so that they are no longer subject to the major source rule.

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•	Of the total 30 wool fiberglass manufacturing facilities in the United States, 20 are now area
sources. Many of the remaining 10 major sources have announced plans to become area sources
in the near future.

•	The final rule regulates gas-fired furnaces at wool fiberglass manufacturing facilities that are
area sources to control their emissions of chromium compounds, including highly-toxic
hexavalent chromium.

•	Area sources currently emit low levels of chromium compounds. As furnaces age, emissions of
this toxic pollutant can increase over time. EPA set the chromium compound emissions limits for
areas sources at the levels currently demonstrated by well-performing facilities. While this rule
will not result in chromium emissions reductions from current levels, the chromium emission
limits in this rule will prevent significant future increases in chromium compound emissions.

•	The area source rule will refer to the major source rule's compliance, measurement,
recordkeeping, reporting, monitoring, startup, shutdown and malfunction requirements.

Final Wool Fiberglass Major Source Rule

Risk Review

•	EPA conducted a risk review based on actual emissions from wool fiberglass manufacturing and
found that risk is acceptable with a maximum individual lifetime cancer risk of 20-in-l million.
These risk are driven by emissions of formaldehyde and hexavalent chromium.

•	EPA found that one furnace emitted chromium at a higher rate than the other furnaces due to
furnace design, construction practices and raw material choice. The Agency concluded that other
wool fiberglass manufacturing facilities could construct a similar furnace having similar
chromium emissions.

•	In response, EPA conducted an auxiliary risk analysis to evaluate the risk that would result if
other wool fiberglass furnaces had similar emission rates and found the maximum individual
lifetime cancer risk could be as high as 400-in-a million. Additionally, EPA found that
chromium emissions increase exponentially over time as a result of furnace refractory
degradation.

•	To prevent the escalation of chromium emissions from wool fiberglass furnaces and provide an
ample margin of safety, EPA concluded that chromium emissions could be further reduced cost
effectively. EPA is finalizing limits for chromium from gas-fired furnaces at 0.00025 lb/ton of
glass pulled further reducing chromium emissions from furnaces located at major sources by 524
pounds per year.

Technology Review

•	EPA also conducted a technology review for the Wool Fiberglass Manufacturing source category
and found that there are improvements in technology that will help further reduce emissions from
furnaces. As a result, the Agency is amending the particulate matter (PM) limit for existing and
new glass-melting furnaces.

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•	EPA reviewed the source category to determine if all hazardous air pollutants are regulated
appropriately and if all sources are subject to emission limits. As a result of this review, EPA is:

o removing formaldehyde as an emissions surrogate for phenol and methanol; and

o setting emission limits for phenol, formaldehyde and methanol for flame attenuation (FA)
lines that will maintain emissions of these compounds current low levels.

•	EPA is deferring action on emissions limits for phenol, methanol and formaldehyde for rotary
spin lines, pending new information. The Agency has issued a request for information under
Section 144 of the Clean Air Act to gather more data to better inform future rulemakings.

•	The final rule eliminates the exemptions to emission limits and standards during periods of
startup, shutdown and malfunction to ensure the standards are consistent with the United States
Court of Appeals for the District of Columbia Circuit's vacatur of similar provisions in other
rules. EPA is requiring work practices standards, as demonstrated by the best performers in this
industry for periods of startup and shutdown.

o During startup, gas-fired glass-melting furnaces can preheat an empty furnace using only
natural gas or other clean fuels. Electric furnaces can startup using only glass cullet and
natural gas; and

o Capture and control all emissions during startup and shutdown using equipment operated
in the manner that showed compliance during the most recent performance test.

Final Mineral Wool Major Source Rule
Risk Review

•	EPA conducted a risk review based on actual emissions from mineral wool production and found
that risk is acceptable at a maximum individual lifetime cancer risk of 10-in-l million. These
risks are driven by emissions of formaldehyde.

Technology Review

•	EPA evaluated the current technology and concluded that no new technologies are in use that
would cost-effectively further reduce emissions of any regulated hazardous air pollutant.

•	EPA reviewed the source category to determine if all hazardous air pollutants are regulated
appropriately and if all sources are subject to emission limits. As a result of this review, EPA is:

o removing carbon monoxide as an emissions surrogate for carbonyl sulfide;

o removing formaldehyde as a surrogate for phenol and methanol;

o setting emission limits for carbonyl sulfide, hydrogen flouride and hydrogen chloride for
four subcategories of new and existing cupolas; and

o setting emission limits for phenol, formaldehyde and methanol for three subcategories of
new and existing combined collection/curing lines.

•	The final rule eliminates exemptions to emission limits and standards during periods of startup,
shutdown and malfunction to ensure the standards are consistent with the United States Court of
Appeals for the District of Columbia Circuit's vacatur of similar provisions in other rules. EPA is
promulgating work practices standards, as demonstrated by the best performers in this industry,
for these periods.

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• Mineral wool facilities will be required to either use only natural gas or other clean fuel in the
cupola, or to use the work practices demonstrated by the best performers to control emissions
during startup and shutdown (i.e., to capture and control all emissions using control equipment
operated in the manner that showed compliance during the most recent performance test.)

Compliance Dates for the Final Rules

•	Startup, shutdown and malfunction provisions will be effective immediately upon publication of the
final rules.

•	Existing impacted wool fiberglass plants will have 2 years to comply with these revised standards.
Existing mineral wool plants will have 3 years to comply. Please see the tables on the last page of
this fact sheet for the emission limits for each type of facility.

BACKGROUND

•	The Clean Air Act requires the EPA to regulate toxic air pollutants from large industrial facilities in
two phases:

•	The first phase is "technology-based," where the EPA develops standards for controlling the
emissions of air toxics from sources in a source category. These Maximum Achievable Control
Technology (MACT) standards are based on emission levels that are already being achieved by the
better-controlled and lower-emitting sources in an industry.

•	The second phase is a "risk-based" approach called residual risk. Within 8 years of setting the
MACT standards, the Clean Air Act directs EPA to assess the remaining health risks from each
source category to determine whether the MACT standards protect public health with an ample
margin of safety and also protect against adverse environmental effects. Here, EPA must determine
whether more health-protective standards are necessary or cost effective.

•	Also, every 8 years after setting the air toxics standards, the Clean Air Act requires that EPA review
and revise the standards, if necessary, to account for process changes, including improvements in air
pollution controls and/or prevention.

•	Additionally, under the Urban Air Toxics Strategy, EPA regulates area sources of 33 urban air toxics
presenting the greatest threat to human health and the environment in urban areas.

•	The previously-issued air toxic standards for mineral wool and wool fiberglass production processes
are part of 96 air toxic standards that require 174 industry sectors to eliminate 1.7 million tons of 187
toxic air pollutants. Congress listed these toxic air pollutants in the Clean Air Act.

FOR MORE INFORMATION ON THF FTNAT, RTTTFS

•	Interested parties can download the notice from the EPA's web site at the following addresses:
http://www.epa.gov/ttn/atw/minwool/minwopg.html and
http://www.epa.gov/ttn/atw/woolfib/woolfipg.html.

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•	Today's final rules and other background information are also available either electronically at
http://www.regulations.gov, the EPA's electronic public docket and comment system, or in hardcopy
at the EPA Docket Center's Public Reading Room.

o The Public Reading Room is located in the EPA Headquarters Library, Room Number 3334 in
the EPA WJC West Building, located at 1301 Constitution Avenue, NW, Washington, DC.

Hours of operation are 8:30 a.m. to 4:30 p.m. eastern standard time, Monday through Friday,
excluding federal holidays,
o Visitors are required to show photographic identification, pass through a metal detector and sign
the EPA visitor log. All visitor materials will be processed through an X-ray machine as well.
Visitors will be provided a badge that must be visible at all times,
o Visitors must show valid picture identification to gain access to the meeting room. The REAL ID
Act, passed by Congress in 2005, established new requirements for entering federal facilities.
Visitors holding driver's licenses issued by Alaska, American Samoa, Arizona, Kentucky,
Louisiana, Maine, Massachusetts, Minnesota, Montana, New York, Oklahoma or the state of
Washington must present an additional form of identification to enter the federal building, such
as federal employee badges, passports and military identification cards.

•	Materials for this final action can be accessed using Docket ID Numbers EPA-HQ-OAR-2010-1041
and EPA-HQ-OAR-2010-1042.

•	For further information, contact Susan Fairchild of the EPA's Office of Air Quality Planning and
Standards by phone at (919) 541-5167, or by email at: fairchild.susan@epa.gov.

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Final Rule Emission Limits

EPA is finalizing this emission limit for area sources in the Wool Fiberglass Manufacturing source
category:

Process

Subcategory

Pollutant

Emission Limit
(lb/ton)

Glass-Melting
Furnace

Gas-Fired Glass-
Melting Furnace

Chromium
Compounds

0.00025

EPA is finalizing these emission limits for major sources in the Wool Fiberglass Manufacturing source
category:

Process

Subcategory

Pollutant

Emission Limit
(lb/ton)

New and Existing Glass-Melting Furnaces

PM

0.33



Gas-fired Glass-
Melting Furnace

Chromium
Compounds

0.00025

New Flame Attenuation Lines

Phenol

0.44





Formaldehyde

2.6





Methanol

0.35

Existing Flame Attenuation Lines

Phenol

1.4





Formaldehyde

5.6





Methanol

0.50

EPA is finalizing these emission limits for major sources in the Mineral Wool Manufacturing source
category:







Emission Limit

Process

Subcategory

HAP

(lb/ton)



Existing Open-Top

Carbonyl Sulfide

6.8



New Open Top



3.2



Existing Closed Top



3.4



New Closed Top



0.062



Existing Processing

Hydrogen Flouride

0.16

Cupolas

Slag

Hydrogen Chloride

0.44

New Processing Slag

Hydrogen Flouride

0.015





Hydrogen Chloride

0.012



Existing Not

Hydrogen Flouride

0.13



Processing Slag

Hydrogen Chloride

0.43



New Not Processing

Hydrogen Flouride

0.018



Slag

Hydrogen Chloride

0.015

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Bonded Lines

Vertical (Existing and
New)

Formaldehyde

2.4

Phenol

0.71

Methanol

0.92

Horizontal (Existing
and New)

Formaldehyde

0.63

Phenol

0.12

Methanol

0.049

Drum (Existing and
New)

Formaldehyde

0.17

Phenol

0.85

Methanol

0.28

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