Paragraph 4

The addition of dangerous substances to determine the quantity present at an establishment shall be carried out according to the following rule:—

if the sum

\frac{q_{1}}{Q} + \frac{q_{2}}{Q} + \frac{q_{3}}{Q} + \frac{q_{4}}{Q} + \frac{q_{5}}{Q} + . . . >1

where

q_x

the quantity of dangerous substances x (or category of dangerous substances) falling within Parts 2 or 3 of this Schedule,

the relevant threshold quantity from Parts 2 or 3,

then the establishment is covered by the relevant requirements of these Regulations.

This rule will apply for the following circumstances—

(a)

for substances and preparations appearing in Part 2 at quantities less than their individual qualifying quantity present with substances having the same classification from Part 3, and the addition of substances and preparations with the same classification from Part 3;

(b)

for the addition of categories 1, 2 and 9 present at an establishment together;

(c)

for the addition of categories 3, 4, 5, 6, 7a, 7b and 8, present at an establishment together.