As the English loanwords, no. With the original Japanese meanings, still no.
In English, ecchi has come to refer to suggestive material or light sexual content (i.e. skimpy clothes, bare breasts, etc.), and hentai defines full-on pornographic material (exposed sex organs, penetration, etc.). Kinda the difference between PG-13 and R.
In Japanese, "ecchi" is how you'd pronounce the English letter "H". Hentai is "pervert" and is used to describe people, not media. "H" is often used to denote something is of adult content (H anime, H manga, etc.), but it isn't really derived from "hentai" (seems the origin of "ecchi" is uncertain and disputed...). More commonly, though, the term "ero" (short for "erotic" or erotica") is used to describe sexual stuff (ero manga, eroge (erotic game), etc).