Pursuant to § 981.8, the definition of inedible kernel is modified to mean a kernel, piece, or particle of almond kernel with any defect scored as serious damage, or damage due to mold, gum, shrivel, or brown spot, as defined in the United States Standards for Shelled Almonds, or which has embedded dirt or other foreign material not easily removed by washing: Provided, That the presence of web or frass shall not be considered serious damage for the purposes of determining inedible kernels, pieces, or particles of almond kernels.