The NFL is proposing new mold rules that will make finding mold on the football field harder, a team spokesman told The Associated Press on Tuesday.

The league is also proposing a new rule requiring teams to wear a mask to protect players from mold in their players’ helmets, helmets and facemasks, which would reduce the likelihood of mold on a player’s head or neck.

The proposed changes would apply to players and coaches, not their parents or guardians.

Mold, a common health hazard in children and adults, can cause serious health problems including infections and even death.

The World Health Organization and other organizations say the incidence of mold in the United States has more than doubled since 1990, when the league began enforcing mold rules.

The new mold regulations were expected to be introduced next week.