The striker scored the only goal of the game in the 46th minute to keep Frank Lampard sides’ fate in their own hands.
In the celebrations that followed Richarlison’s goal, a lit blue smoke canister was thrown on to the pitch by supporters.
Richarlison responded by picking the object up and throwing it, although it was unclear where it landed.
A club spokesperson said: “We will look into the matter but, as far we we are concerned, Richarlison was attempting to throw it out of the ground.”
In February, Liverpool midfielder Harvey Elliott was contacted by the FA after handling a red flare following the side’s Carabao Cup victory at Wembley.
Pyrotechnics are banned from football stadiums in England.
Everton remain in the relegation zone with five games left to play.
But the victory moves them within two points of Burnley and Leeds, with the Toffees having a game in hand on their two rivals.
Additional reporting from PA