| Country | Annual Average μg/m3 | 24 hours Average μg/m3 | Date of Implementation |
| U.S. | 15 | 35 | December 17, 2006 |
| EU | 25 | NA | Issued January 1, 2010. Fully implementation on January 1, 2015 |
| Japan | 15 | 35 | September 9, 2009 |
| China | 35 | 75 | Effective 2016 (Public hearing period) |
| WHO | 10 | 25 | Highly recommended |