Yes, FUMING is a Scrabble word!

Letter values in Scrabble US: F 4, U 1, M 3, I 1, N 1, G 2.

Is it a valid word?

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

be mad, angry, or furious
emit a cloud of fine particles
treat with fumes, expose to fumes, especially with the aim of disinfecting or eradicating pests
be wet with sweat or blood, as of one's face