FACT SHEET

REVISION TO METHOD 23 FOR THE DETERMINATION OF POLYCHLORINATED DIBENZO-
P-DIOXINS AND POLYCHLORINATED DIBENZOFURANS FROM STATIONARY SOURCES

ACTION

•	On December 17, 2019, the U.S. Environmental Protection Agency (EPA) proposed to revise
EPA Method 23. Method 23 is used to measure polychlorinated dibenzo-p-dioxins (PCDDs)
and polychlorinated dibenzofurans (PCDFs) from stationary air sources.

•	EPA promulgated Method 23 on February 13,1991 (56 FR 5758). It has not been updated or
revised since its original promulgation. Most current stationary source sampling and
analysis methods have been revised to a new consistent format. This proposed action
would revise the format of the method to be consistent with other methods.

•	These proposed revisions harmonize the laboratory procedures and requirements with EPA
Office of Water methods. This proposed revision would replace prescriptive requirements
for materials and instrument parameters with performance-based quality requirements
that provide flexibility to implement best analytical practices.

•	EPA is proposing to include polycyclic aromatic hydrocarbons (PAHs) and polychlorinated
biphenyls (PCBs) in the method. This would provide EPA with a semivolatile compliance
method for these regulated target compounds in one comprehensive method.

•	The proposed revisions will improve the accuracy of Method 23 and will provide flexibility
to stack testers and analytical laboratories who measure semivolatile organic compounds
(SVOC) from stationary sources while ensuring that the stack testing community can
consistently implement the method across emissions sources and facilities.

•	This action would give facilities, source test teams and their analytical laboratories options
to reduce field sampling cost when multiple semivolatile toxic compounds are required to
demonstrate air release compliance.

•	EPA will accept comment on this proposed rule for 60 days after it is published in the
Federal Register.

BACKGROUND

•	EPA established requirements for measuring PCDD/PCDF in stationary sources in 1991. Over
the past nearly 30 years, technical advances for measuring PCDD/PCDF have occurred.

•	Most EPA stationary source compliance methods were reformatted in the 1990's. Method
23 is overdue for a format revision to the current Emissions Monitoring and Management
Council standard.


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HOW TO COMMENT

• Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2016-0677, by one of
the following methods:

o http://www.regulations.gov. Follow the on-line instructions for submitting
comments.

o E-mail: a-and-r-docket@epa.gov. Include Docket ID No. EPA-HQ-OAR-2016-0677 in

the subject line of the message,
o Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-2016-0677.
o Mail: U.S. Environmental Protection Agency, EPA Docket Center, Docket ID No. EPA-
HQ-OAR-2016-0677, Mail Code 28221T, 1200 Pennsylvania Avenue NW,

Washington, DC 20460. Please include two copies,
o Hand Delivery: U. S. Environmental Protection Agency, EPA West (Air Docket), 1301
Constitution Avenue, Northwest, Room 3334, Washington, DC. Such deliveries are
only accepted during the Docket's normal hours of operation, and special
arrangements should be made for deliveries of boxed information.

FOR MORE INFORMATON

•	Interested parties can download the rule from EPA's web site on the Internet under
Proposed Test Methods at the following address: http://www.epa.gov/emc.

•	Other places to read the proposed rule and background information (use Docket ID No.
EPA-HQ-OAR-2016-0677):

•	EPA's electronic public docket and comment system at
http://www. regulations, gov.

•	The EPA Docket Center's Public Reading Room (for hard copies).

o The Public Reading Room is located at EPA Headquarters, Room Number 3334 in

EPA West Building, 1301 Constitution Avenue, NW, Washington,
o DC. Hours of operation are 8:30 a.m. to 4:30 p.m. eastern standard time,

Monday through Friday, excluding federal holidays,
o You will have to show photo identification, pass through a metal detector, and
sign the EPA visitor log. Any materials you bring with you will be processed
through an X-ray machine as well. You will be provided a badge that must always
be visible.

•	For further information about the rulemaking, contact Raymond Merrill at EPA's Office of
Air Quality Planning and Standards at (919) 541-5225 or merrill.raymond@epa.gov.


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