(From the AP) High school baseball teams in California will have to follow new safety standards for the metal bats they use under rules released Wednesday, in the wake of accidents that brought national attention to the issue of the bats’ safety. The aluminum bats will be tested to limit the speed of the balls they hit and may include a tamper-proof decal that would change color if the bat was modified to improve performance. While in production, the new bats will be broken in to ensure that their performance — the speed balls travel and the amount they bounce — could not be improved over time with wear.

Schools will be required to use the new bats in January if they are available.

The changes came after 16-year-old pitcher Gunnar Sandberg of Marin County suffered a major head injury when he was hit in the head last March by a line drive off a metal bat.

Read more here: California high schools face restrictions on metal bats