reg 5 NOTES TO PARTS A AND B
The addition rule in paragraph 4 will apply for the following circumstances:– (a) for substances and preparations appearing in Part A at quantities less than their individual controlled quantity present with substances having the same classification from Part B, and the addition of substances and preparations with the same classification from Part B; (b) for the addition of categories 1, 2 and 10 from Part B present together; (c) for the addition of categories 3, 4, 5, 6, 7, 8 and 9 from Part B present together.