The ECB guidelines recommend that no cricketer under the age of 19 should bat against a hard ball without wearing a helmet unless they have written parental consent to do so.
It is also recommende that wicket-keepers wear a helmet when facing a hard ball.
The ECB acted after fears that it could face litigation if young players sustained head injuries and, after taking legal advice, the SCU has followed suit.
Last year the ECB, concerned about "burn-out" of young players, introduced guidelines restricting the number of overs they can bowl. The SCU also took this on board.