G/TBT/N/USA/1564/Add.1  
 
21 March 2023  
(23-2035) Page: 1/2 
Committee on Technical Barriers to Trade  Original: English  
 
 
NOTIFICATION  
Addendum  
The following communication , dated  21 March 2023, is being circulated at the request of the 
delegation of the United States of America . 
 
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Title:  EPA Method 23 - Determination of Polychlorinated Dibenzo -p-Dioxins and Polychlorinated 
Dibenzofurans From Stationary Sources  
 
Reason for Addendum:  
[ ] Comment period changed - date:   
[ ] Notified measure adopted - date:  
[X] Notified measure published - date: 20 March 2023  
[X] Notified measure enters into force - date: 20 March 2023  
[X] Text of final measure available from1:  
https://www.govinfo.gov/content/pkg/FR -2023-03-20/html/2023 -04958.htm  
https://www.govinfo.gov/content/pkg/FR -2023-03-20/pdf/2023 -04958.pdf  
https://members.wto.org/crnattachments/2023/TBT/USA/final_measure/23_2128_00_
e.pdf 
[ ] Notified measure withdrawn or revoked - date:  
Relevant symbol if measure re -notified:   
[ ] Content or scope of notified measure changed  and text available from1:  
New deadline for comments (if applicable):   
[ ] Interpretive guidance issued and text available from1:  
[ ] Other:  
 
Description:  TITLE: EPA Method 23 --Determination of Polychlorinated Dibenzo -p-Dioxins and 
Polychlorinated Dibenzofurans From Stationary Sources  
AGENCY: Environmental Protection Agency (EPA)  
ACTION: Final rule  
SUMMARY: This action finalizes editorial and technical revisions to the Environmenta l Protection 
Agency's (EPA's) Method 23  (Determination of Polychlorinated Dibenzo -p-Dioxins, Polychlorinated 
Dibenzofurans, and Polycyclic Aromatic Hydrocarbons from Stationary Sources). Final revisions 
include incorporating true, comprehensive, and stable  isotope dilution for quantifying target 
 
1 This information can be provided by including a website address, a pdf attachment, or other 
information on where the text of the final /modified  measure and/or interpretive guidance can be obtained.  G/TBT/N/USA/1564/Add.1  
 
- 2 - 
 
  compounds using corresponding carbon -13 labeled compounds for each target compound including 
most of the polycyclic aromatic hydrocarbons (PAH) and changing the method quality control from 
the current prescriptive f ormat to a more flexible performance -based approach with specified 
performance criteria. We are also finalizing revisions that expand the list of target compounds of 
Method 23 to include PAH and polychlorinated biphenyls (PCB). The final revisions allow fa cilities 
and their test teams flexibility when sampling and measuring polychlorinated dibenzo -p-dioxins and 
polychlorinated dibenzofurans (PCDD/PCDF), PAH, and PCB from stationary sources with a 
comprehensive isotope dilution method while ensuring that the  stack testing community can 
consistently implement the method across emissions sources and facilities.  
DATES: This final rule is effective on 20 March 2023. The incorporation by reference (IBR) of certain 
publications listed in the rule is approved by the  Director of the Federal Register as of 20 March 
2023.  
This final rule and the proposed rule notified as G/TBT/N/USA/1564  are identified by Docket Number 
EPA-HQ-OAR-2016-0677. The Docket Folder is available from Regulations.gov at 
https://www.regulations.gov/docket/EPA -HQ-OAR-2016-0677/document  and provides access to 
primary and supporting doc uments as well as comments received. Documents are also accessible 
from Regulations.gov  by searching the Docket Number.  
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