Sure, can you add to the table the unit of measure values for the product category codes of Spices and Herbs?
select unit_of_measure from Ref_Product_Categories where 
product_category_code = 'Herbs' or product_category_code = 'Spices'
unit of measure values refers to unit_of_measure; product category codes of Spices and Herbs refers to product_category_code = 'Herbs' or product_category_code = 'Spices';