The Product:

Toilets (also known as water closets) include tank-type toilets that are either gravity or pressure assist and either single- or dual-flush. 

The Standard:

Congress established national toilet standards as part of the Energy Policy Act of 1992, and they took effect in 1994. Congress instructed DOE to update the standards when the American Society of Mechanical Engineers (ASME) amended their standards. In 2010, with no ASME revisions on the books, DOE officially waived federal preemption of the 1.6 gallon-per-flush (gpf) national toilet standard. This waiver of federal preemption allows states to set standards provided they are more stringent than the national standard.

California, Colorado, the District of Columbia, Georgia, Massachusetts, Nevada, New York, Texas, Rhode Island, Washington, and New York City have adopted toilet efficiency standards that require products to use no more than 1.28 gpf. Products meeting the 1.28 gpf level currently meet the qualifications for the EPA WaterSense program (which is similar to ENERGY STAR but focused on helping consumers identify water-efficient products).


Toilets are one of the primary users of water in the home, accounting for 26% of an average home's indoor water usage, according to a 2016 Water Research Foundation study. In the U.S., there are an average of 1.9 toilets per home. ASAP estimates that 73% of all residential toilet models currently being offered for sale and 48% of all commercial toilet models currently being offered for sale meet the 1.28 gpf standard.


Federal Date States
2024 MD Standard Effective
2023 ME Standard Effective
2023 RI Standard Effective
2022 MD Standard Adopted
2022 DC Standard Effective
2022 NY Standard Effective
2022 MA Standard Effective
2022 NJ Standard Effective
2021 ME Standard Adopted
2021 RI Standard Adopted
2021 MA Standard Adopted
2021 NJ Standard Adopted
2021 WA Standard Effective
2020 DC Standard Adopted
2020 NV Standard Effective
2019 NY Standard Adopted
2019 NV Standard Adopted
2019 WA Standard Adopted
2016 CO Standard Effective
2016 CA Standard Effective
2015 CA Standard Adopted
2014 CO Standard Adopted
2014 CA Standard Effective
2014 TX Standard Effective
2012 GA Standard Effective
2010 GA Standard Adopted
2009 TX Standard Adopted
2007 CA Standard Adopted
1st Federal Standard Effective 1994
EPACT Initial Federal Legislation Enacted 1992
1st Federal Standard Adopted (Congress) 1992

Timeline reflects state standards from 2001 to present; federal standards from inception to present.