World Cup 2014: What is the vanishing spray being used in Brazil?

The disappearing foam has been a new addition for this tournament

Japanese referee Yuichi Nishimura sprays a line after calling for a free kick for Brazil (Getty Images)

One week into the tournament and so far the World Cup has been a roaring success.

Not only has the tournament served up a hearty buffet of deliciously exciting football for its viewers all round the world, but they have also been treated to the additional garnish of new technology.

Goal-line technology has been introduced, mostly providing moments of comedy but nevertheless proving itself to be highly useful.

However the real star of the tournament has been the referees' new magic spray. Used to mark out the correct distance the wall should stand from the ball at free kicks, the natty disappearing foam has taken the World Cup by storm.

FOLLOW OUR WORLD CUP LIVE BLOG HERE

For fans of South American football, the foam spray is nothing new, having been used in league matches on the continent for some years, but for the huge global audience, these are bold new days.

No more can the defensive wall creep forward, cramping the free kick taker's style, when the referee's back is turned and in theory we should now see more goals scored from free kicks.

But what is the magic disappearing foam made of? According to LiveScience it is: “a mixture of butane, isobutane and propane gas; a foaming agent; water; and other chemicals.

"When it leaves the can, the gas depressurizes and expands, creating small, water-covered droplets on the field. The butane mixture later evaporates, leaving only water and surfactant residue behind.”

The spray is the brainchild of Argentine journalist Pablo Silva who developed the spray called "9:15 Fairplay," a reference to the metric equivalent of the free-kick distance requirement.

The spray hasn't just been a new concept for fans and players to get to grips with, it also appears some referees are still getting the hang of it...

Some referees went a bit overboard with their new spray (Twitter)

If this photo is anything to go by, then you certainly wouldn't want to pass out at a party attended by Mexican referee Marco Rodriguez, particularly if there was any shaving foam lying around.