Seven public health groups and several pediatricians are suing the Food and Drug Administration for delaying regulation of e-cigarettes and some tobacco products.

The FDA brought e-cigarettes, cigars and hookah within its oversight in 2016 when it expanded the definition of tobacco products. It planned to require such products that were on the market as of Aug. 8, 2016, when the so-called deeming rule was enacted, to undergo review starting this year.

Last summer, the agency extended the deadline as part of a sweeping plan to overhaul tobacco regulation. Under the revised timeline, manufacturers won’t need to file until 2021 for combustible products like cigars and until 2022, for noncombustible products like e-cigarettes.