Paragraph 5

The following rule governing the addition of hazardous substances, or categories of hazardous substances, applies where appropriate.

In the case of an establishment where no individual hazardous substance is present in a quantity above or equal to the relevant controlled quantity, the following rule must be applied to determine whether the establishment is covered by the relevant requirements in these Regulations.

These Regulations apply to establishments if the sum q₁/Q_{L1 +}q₂/Q_{L2 +}q₃/Q_{L3 +}q₄Q_{L4 +}q₅Q_{L5 +.}..is greater than or equal to 1, where q_x= the quantity of hazardous substance x (or category of hazardous substances) falling within Part 1 or Part 2 of this Schedule; and Q_LX= the relevant controlled quantity for hazardous substance x (or category of hazardous substances x) from Column 2 of Part 1 or from Column 2 of Part 2 of this Schedule (except for those substances for which column 2 contains a quantity Q*, in which case, for Hydrogen, Q is equal to 5, and for Liquified petroleum gas and Natural Gas (including liquefied natural gas), Q is equal to 50).

This rule must be used to assess the health hazards, physical hazards and environmental hazards. It must therefore be applied three times—

(a)

for the addition of hazardous substances listed in Part 2 that fall within acute toxicity category 1, 2, or 3 (inhalation route) or STOT SE category 1, together with hazardous substances falling within section H, entries H1 to H3 of Part 1;

(b)

for the addition of hazardous substances listed in Part 2 that are explosives, flammable gases, flammable aerosols, oxidising gases, flammable liquids, self-reactive substances and mixtures, organic peroxides, pyrophoric liquids and solids, oxidising liquids and solids, together with hazardous substances falling within section P, entries P1 to P8 of Part 1;

(c)

for the addition of hazardous substances listed in Part 2 that fall within hazardous to the aquatic environment acute category 1, chronic category 1 or chronic category 2, together with hazardous substances falling within section E, entries E1 and E2 of Part 1.

The relevant provisions of these Regulations apply where any of the sums obtained by (a), (b) or (c) is greater than or equal to 1.