G/TBT/N/USA/1620/Rev.1/Add.1  
 
30 June 2021  
(21-5229) Page: 1/2 
Committee on Technical Barriers to Trade  Original: English  
 
 
NOTIFICATION  
Addendum  
The following communication , dated  30 June 2021 , is being circulated at the request of the 
delegation of the United States of America . 
 
_______________  
 
 
Title: Improvements for Heavy -Duty Engine and Vehicle Test Procedures, and Other Technical 
Amendments  
 
Reason for Addendum:  
[  ] Comment period changed - date:   
[  ] Notified measure adopted - date:  
[X] Notified measure published - date: 29 June 2021  
[X] Notified measure enters into force - date: 29 July 2021  
[X] Text of final measure available from1:  
https://www.govinfo.gov/content/pkg/FR -2021-06-29/html/2021 -05306.htm  
https://www.govinfo.gov/content/pkg/FR -2021-06-29/pdf/2021 -05306.pdf  
https://members.wto.org/crnattachments/2021/TBT/USA/final_measure/21_4408_00_
e.pdf 
[  ] Notified measure withdrawn or revoked - date:  
Relevant symbol if meas ure 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: Improvements for Heavy -Duty Engine and Vehicle Test Procedures, and Other 
Technical Amendments  
AGENCY: Environmental Protection Agency (EPA)  
ACTION: Final rule  
SUMMARY: The Environmental Protection Agency (EPA) is amending the test procedures for h eavy-
duty engines and vehicles to improve accuracy and reduce testing burden. EPA is also making other 
regulatory amendments concerning light -duty vehicles, heavy -duty vehicles, highway motorcycles, 
locomotives, marine engines, other nonroad engines and ve hicles, and stationary engines. These 
amendments affect the certification procedures for exhaust emission standards and related 
 
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/1620/Rev.1/Add.1  
 
- 2 - 
 
  requirements. EPA is finalizing similar amendments for evaporative emission standards for nonroad 
equipment and portable fuel co ntainers. The amendments increase compliance flexibility, harmonize 
with other requirements, add clarity, correct errors, and streamline the regulations. Given the nature 
of the amendments, they will have neither significant environmental impacts nor signi ficant 
economic impacts for any sector.  
DATES: This final rule is effective on 29 July 2021. The incorporation by reference of certain 
publications listed in this regulation is approved by the Director of the Federal Register as of 29 July 
2021.  
This final  rule and other actions notified under the symbol G/TBT/N/ USA/1620  are identified by 
Docket Number EPA -HQ-OAR-2019-0307. The Docket Folder is available on Regulations.gov at 
https://www.regulations.gov/docket/EPA -HQ-OAR-2019-0307/document  and provides access to 
primary and supporting documents as well as comments received. Documents are also accessible 
from Regulations.gov  by searching the Docket Number. WTO Members a nd their stakeholders are 
asked to submit comments to the USA TBT Enquiry Point . Comments received by the USA TBT 
Enquiry Point from WTO Members and their stakeholders will be shared with the regulator a nd will 
also be submitted to the Docket  on Regulations.gov if received within the comment period.  
__________