Yes, EMITTING is a Scrabble word!

Letter values in Scrabble US: E 1, M 3, I 1, T 1, T 1, I 1, N 1, G 2.

Is it a valid word?

EMITTING is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

expel (gases or odors)
give off, send forth, or discharge; as of light, heat, or radiation, vapor, etc.
express audibly; utter sounds (not necessarily words)

Also: pass off, give out, give off, let out, let loose.