All power-driven meat grinders of the worm type shall be so constructed that meat can be safely fed to the worm by any of the following methods:
- (1) By a mechanical method of feeding the worm.
- (2) By the use of a permanently attached neck to the cylinder enclosing the worm which shall have an opening of not more than 2 1/2 inches in diameter at a point at least 4 1/2 inches above the worm.
- (3) Any other means of protection approved by the Board.