Regulation of Dangerous Goods

Legal Requirements

Pursuant to section 110 of Cap. 295G:

(1) A person must not store, or cause or permit to be stored, 2 or more types of S2DG (whether or not of the same class) that are incompatible in a licensed store.

(2) For subsection (1), 2 or more types of S2DG are incompatible if, when they come into contact with each other or all others—

(a) a combustion occurs or is likely to occur;

(b) considerable heat is, or is likely to be, generated;

(c) a flammable, asphyxiant, oxidizing or toxic gas is, or is likely to be, generated;

(d) a corrosive substance is, or is likely to be, formed; or

(e) a chemically unstable substance is, or is likely to be, formed.

(3) Without limiting subsection (1)—

(a) Class 2 S2DG must not be stored with S2DG of a different class;

(b) Class 3 S2DG must not be stored with S2DG of a different class, except Class 3A S2DG or paint materials that are Class 3 S2DG or Class 8 S2DG;

(c) Class 3A S2DG must not be stored with S2DG of a different class, except Class 3 S2DG or paint materials that are Class 3 S2DG or Class 8 S2DG; and

(d) Class 4 S2DG, Class 5 S2DG, Class 6.1 S2DG, Class 8 S2DG or Class 9 S2DG must not be stored with Class 2 S2DG, Class 3 S2DG or Class 3A S2DG, or S2DG of any other class so specified for the purposes of this paragraph in the code of practice.

(4) A person who contravenes subsection (1) commits an offence and is liable on conviction to a fine at level 4 and to imprisonment for 2 months.

General Application

Multiple types of DG shall not be stored together in a licensed store if they are incompatible.  This chapter provides a practical guidance on how to determine the compatibility of DG to facilitate the application for a licensed store.  To determine the compatibility of multiple types of DG, relevant compatibility tables at 2.3.3.2 and the compatibility groups and rules at column 10 of the DG List shall be observed.

Considering the dangerous consequences and restrictions pursuant to section 110(2)&(3) of Cap. 295G as well as the packing requirements for the DG being complied with during storage of DG, the compatibility tables in 2.3.3.2 are prepared and compatibility groups and rules are assigned to DG at column 10 of the DG List for the purpose of determining the compatibility of different DG.

The compatibility rules stated in this chapter do not apply to the storage of multiple types of DG when each type of DG does not exceed the GEQ / IEQ / SEQ (as the case may be) and the aggregate quantity does not exceed the aggregate EQ.

Determining the Compatibility

The methods on determining the compatibility of DG are as below and a flowchart is provided at 2.3.6 of this Chapter for easy reference:

(1) Identify the classes of DG by referring to the DG List;

(2) Check the relevant compatibility tables in 2.3.3.2 for respective classes of DG. If it appears that the DG are incompatible, they are not allowed to be stored together in a licensed store.  Otherwise, step (3) shall be followed; and

(3) Check if there is any compatibility groups and compatibility rules for each DG at column 10 of the DG List:

> if no, they are compatible; or

> if yes, check the compatibility groups (CG) and compatibility rules (CR) for each DG at column 10 by making reference to the descriptions of CG and CR in tables in 2.3.3.3.1 to determine the compatibility.

Compatibility Tables

The general provisions for incompatibility between various classes of DG are shown in the “compatibility tables” below.  In using the compatibility tables, the class of DG only denotes the primary hazard.  Since the properties of different DG within each class may vary greatly, the column 10 of the DG List shall always be referred beforehand.  Pursuant to section 110(3) of Cap. 295G, 3 compatibility tables are provided for the following 3 groups of DG classes respectively:

(1) Class 2.1, 2.2 & 2.3 DG (para. 2.3.3.2.1);

(2) Class 3, 3A DG and paint materials that are Class 8 DG (para. 2.3.3.2.3); and

(3) Class 4, 5, 6.1, 8 & 9 DG (para. 2.3.3.2.5).

Compatibility Table for Class 2.1, 2.2 & 2.3 DG

Flammable gases (2.1)

O

O

X

Non-flammable, non-toxic gases (2.2)

O

O

O

Toxic gases (2.3)

X

O

O

O   Column 10 of the DG List shall be referred

X    Incompatible

#    Class 2 DG in limited packs are compatible with each other regardless of the table in 2.3.3.2.1 above and their CG & CR

Class 2 DG can be divided into 3 classes:

(1) Class 2.1 DG – flammable gases;

(2) Class 2.2 DG – non-flammable, non-toxic gases which include inert gases and oxidizing gases (compatibility groups shall be referred for oxidizing gases); and

(3) Class 2.3 DG – toxic gases.

The compatibility of Class 2 DG are as follows:

(1) Class 2 DG is incompatible with any other classes of DG;

(2) Flammable gases, oxidizing gases and toxic gases are incompatible with each other;

(3) Inert gases are compatible with flammable gases, toxic gases and oxidizing gases (CG19 & CR7 shall be referred); and

(4) Class 2 DG in limited packs are compatible with each other regardless of (2) and (3) above and their CG & CR.

Compatibility Table for Class 3, 3A DG and paint materials that are Class 8 DG

CLASS

Flammable liquids (3)

O

O

O

Diesel oils, furnace oils and other fuel oils (3A)

O

O

O

Paint materials (8*)

O

O

O

O   Column 10 of the DG List shall be referred and Class 3 or 3A DG, which are immiscible²⁷ with water, are incompatible with any  such DG, which are miscible with water.

*    Only for paint materials that are Class 8 DG.

#    Class 3, 3A DG in limited packs and paint materials in limited packs are compatible with each other regardless of their miscibility and any CG & CR.

²⁷ Miscibility of Class 3 / 3A DG are determined by methods stated in ASTM D1722-09 or relevant recognised national or international standards.

The compatibility of Class 3 or 3A DG are as follows:

(1) Class 3 DG is incompatible with any other classes of DG except Class 3A DG or paint materials that are Class 3 or 8 DG;

(2) Class 3A DG is incompatible with any other classes of DG except Class 3 DG or paint materials that are Class 3 or 8 DG;

(3) Class 3 or 3A DG, which are immiscible with water, are incompatible with any such DG, which are miscible with water; and

(4) Class 3, 3A DG in limited packs and paint materials ) in limited packs are compatible with each other regardless of their miscibility and any CG & CR.

Compatibility Table of Class 4, 5, 6.1, 8 & 9 DG

O   Column 10 of the DG List shall be referred

X Incompatible

*    Class 5.1 or 5.2 DG in table 2.3.3.2.6 below are compatible with  each other.

#    Regardless of the table in 2.3.3.2.5 above and CG & CR of the DG:

       (a) Class 4, 5, 6.1, 8 & 9 DG in limited packs are compatible with each other; and

       (b) Class 4, 5, 6.1, 8 & 9 DG which comprise the same substance but vary only in their water content are compatible with each other.

Compatibility Group (CG) and Compatibility Rule (CR)

For the purpose of determining compatibility, some DG are assigned with CG describing their chemical properties and CR describing their rules of compatibility.  CG and CR are not applicable to DG in limited packs.  The descriptions of various CG and CR are listed below and the CG and CR of different DG are provided in column 10 of the DG List.  In utilizing the CG and CR, the class of DG only denotes the primary hazard regardless of their subsidiary hazards.

Table - List of Compatibility Groups

CG1

Acids

CG1a

Strong acids

CG2

Ammonium compounds

CG3

Bromates

CG4

Chlorates

CG5

Chlorites

CG6

Cyanides

CG7

Heavy metals and their salts

(including their organometallic compounds)

CG8

Hypochlorites

CG9

Lead and its compounds

CG10

Liquid halogenated hydrocarbons

CG11

Mercury and mercury compounds

CG12

Nitrites and their mixtures

CG13

Perchlorates

CG14

Permanganates

CG15

Powdered metals

CG16

Peroxides

CG17

Azides

CG18

Alkalis

CG19

Oxidizing gases (non-flammable & non-toxic)

Table - List of Compatibility Rules

CR1

For arsenic sulphides, incompatible with CG1 – acids or CG1a – strong acids

CR2

Incompatible with CG1a – strong acids

CR3

Incompatible with Class 5.1 DG

CR4

Incompatible with Class 4.1 DG

CR5

Incompatible with CG1 – acids or CG1a – strong acids

CR6

Incompatible with CG18 – alkalis

CR7

Incompatible with CG19 – oxidizing gases

CR8

Incompatible with CG15 – powdered metals

CR9

Incompatible with ammonia

CR10

Incompatible with CG2 – ammonium compounds

CR11

Incompatible with CG2 – ammonium compounds other than AMMONIUM PERSULPHATE (UN 1444)

CR12

Incompatible with CG2 – ammonium compounds other than mixtures of ammonium persulphates and/or potassium persulphates and/or sodium persulphates

CR13

Incompatible with CG3 – bromates

CR14

Incompatible with bromine

CR15

Incompatible with CG4 – chlorates

CR16

Incompatible with chlorine

CR17

Incompatible with CG5 – chlorites

CR18

Incompatible with CARBON TETRACHLORIDE

(UN 1846)

CR19

Incompatible with CG6 – cyanides

CR20       

Incompatible with CG8 – hypochlorites

CR21

Incompatible with iron oxide

CR22

If flashpoint is 60°C or below, incompatible with Class 4.2, 4.3, 5.1 & 5.2 DG

CR23

Incompatible with CG11 – mercury and mercury compounds

CR24

Incompatible with mercury salts

CR25

Incompatible with CG12 – nitrites

CR26

Incompatible with CG13 – perchlorates

CR27

Incompatible with CG14 – permanganates

CR28

Incompatible with CG16 – peroxides

CR29

Incompatible with sulphur

CR30

Incompatible with Class 4.2, 4.3, 5.1 & 5.2 DG except DG of same class

CR31

Incompatible with Class 4.2, 4.3, 5.2 & 8 DG except DG of same class

2.3.3

Determining the Compatibility

2.3.3.1

The methods on determining the compatibility of DG are as below and a flowchart is provided at 2.3.6 of this Chapter for easy reference:

(1) Identify the classes of DG by referring to the DG List;

(2) Check the relevant compatibility tables in 2.3.3.2 for respective classes of DG. If it appears that the DG are incompatible, they are not allowed to be stored together in a licensed store.  Otherwise, step (3) shall be followed; and

(3) Check if there is any compatibility groups and compatibility rules for each DG at column 10 of the DG List:

> if no, they are compatible; or

> if yes, check the compatibility groups (CG) and compatibility rules (CR) for each DG at column 10 by making reference to the descriptions of CG and CR in tables in 2.3.3.3.1 to determine the compatibility.

2.3.3.2

Compatibility Tables

The general provisions for incompatibility between various classes of DG are shown in the “compatibility tables” below.  In using the compatibility tables, the class of DG only denotes the primary hazard.  Since the properties of different DG within each class may vary greatly, the column 10 of the DG List shall always be referred beforehand.  Pursuant to section 110(3) of Cap. 295G, 3 compatibility tables are provided for the following 3 groups of DG classes respectively:

(1) Class 2.1, 2.2 & 2.3 DG (para. 2.3.3.2.1);

(2) Class 3, 3A DG and paint materials that are Class 8 DG (para. 2.3.3.2.3); and

(3) Class 4, 5, 6.1, 8 & 9 DG (para. 2.3.3.2.5).

2.3.3.2.1

Compatibility Table for Class 2.1, 2.2 & 2.3 DG

CLASS

2.1#

2.2#

2.3#

Flammable gases (2.1)

O

O

X

Non-flammable, non-toxic gases (2.2)

O

O

O

Toxic gases (2.3)

X

O

O

O   Column 10 of the DG List shall be referred

X    Incompatible

#    Class 2 DG in limited packs are compatible with each other regardless of the table in 2.3.3.2.1 above and their CG & CR

2.3.3.2.2

Class 2 DG can be divided into 3 classes:

(1) Class 2.1 DG – flammable gases;

(2) Class 2.2 DG – non-flammable, non-toxic gases which include inert gases and oxidizing gases (compatibility groups shall be referred for oxidizing gases); and

(3) Class 2.3 DG – toxic gases.

The compatibility of Class 2 DG are as follows:

(1) Class 2 DG is incompatible with any other classes of DG;

(2) Flammable gases, oxidizing gases and toxic gases are incompatible with each other;

(3) Inert gases are compatible with flammable gases, toxic gases and oxidizing gases (CG19 & CR7 shall be referred); and

(4) Class 2 DG in limited packs are compatible with each other regardless of (2) and (3) above and their CG & CR.

2.3.3.2.3

Compatibility Table for Class 3, 3A DG and paint materials that are Class 8 DG

CLASS

3#

3A#

8*#

Flammable liquids (3)

O

O

O

Diesel oils, furnace oils and other fuel oils (3A)

O

O

O

Paint materials (8*)

O

O

O

O   Column 10 of the DG List shall be referred and Class 3 or 3A DG, which are immiscible²⁷ with water, are incompatible with any  such DG, which are miscible with water.

*    Only for paint materials that are Class 8 DG.

#    Class 3, 3A DG in limited packs and paint materials in limited packs are compatible with each other regardless of their miscibility and any CG & CR.

²⁷ Miscibility of Class 3 / 3A DG are determined by methods stated in ASTM D1722-09 or relevant recognised national or international standards.

2.3.3.2.4

The compatibility of Class 3 or 3A DG are as follows:

(1) Class 3 DG is incompatible with any other classes of DG except Class 3A DG or paint materials that are Class 3 or 8 DG;

(2) Class 3A DG is incompatible with any other classes of DG except Class 3 DG or paint materials that are Class 3 or 8 DG;

(3) Class 3 or 3A DG, which are immiscible with water, are incompatible with any such DG, which are miscible with water; and

(4) Class 3, 3A DG in limited packs and paint materials ) in limited packs are compatible with each other regardless of their miscibility and any CG & CR.

2.3.3.2.5

Compatibility Table of Class 4, 5, 6.1, 8 & 9 DG

CLASS

4.1#

4.2#

4.3#

5.1#

5.2#

6.1#

8#

9#

Flammable solids (4.1)

O

O

O

O

X

O

O

O

Substances liable to
spontaneous combustion (4.2)

O

O

O

X

X

O

O

O

Substances which, in contact with water, emit flammable gases (4.3)

O

O

O

X

X

O

O

O

Oxidizing substances (5.1)

O

X

X

O

X*

O

X

O

Organic peroxides (5.2)

X

X

X

X*

O

O

X

O

Toxic substances (6.1)

O

O

O

O

O

O

O

O

Corrosive substances (8)

O

O

O

X

X

O

O

O 

Miscellaneous dangerous substances or materials (9)

O

O

O

O

O

O

O

O

O   Column 10 of the DG List shall be referred

X Incompatible

*    Class 5.1 or 5.2 DG in table 2.3.3.2.6 below are compatible with  each other.

#    Regardless of the table in 2.3.3.2.5 above and CG & CR of the DG:

       (a) Class 4, 5, 6.1, 8 & 9 DG in limited packs are compatible with each other; and

       (b) Class 4, 5, 6.1, 8 & 9 DG which comprise the same substance but vary only in their water content are compatible with each other.

Table 2.3.3.2.6

UN

Proper shipping name

CLASS

Subsidiary hazard(s)

Packing Group

2014

HYDROGEN PEROXIDE, AQUEOUS SOLUTION

5.1

8

II

2984

HYDROGEN PEROXIDE, AQUEOUS SOLUTION

5.1

-

III

3105

ORGANIC PEROXIDE TYPE D, LIQUID

5.2

8

-

3107

ORGANIC PEROXIDE TYPE E, LIQUID

5.2

8

-

3109

ORGANIC PEROXIDE TYPE F, LIQUID

5.2

8

-

3149

HYDROGEN PEROXIDE AND

PEROXYACETIC ACID, MIXTURE, STABILIZED

5.1

8

II

2.3.3.3

Compatibility Group (CG) and Compatibility Rule (CR)

2.3.3.3.1

For the purpose of determining compatibility, some DG are assigned with CG describing their chemical properties and CR describing their rules of compatibility.  CG and CR are not applicable to DG in limited packs.  The descriptions of various CG and CR are listed below and the CG and CR of different DG are provided in column 10 of the DG List.  In utilizing the CG and CR, the class of DG only denotes the primary hazard regardless of their subsidiary hazards.

Final Scrutiny of the Application for Licensed Store

The application for licensed store shall be subject to the final scrutiny by FSD with the assistance of the Government Laboratory.  Test reports or documents issued by recognised laboratories verifying that the DG do not react dangerously with each other can be provided for further consideration.

Examples of Determining Compatibility

The following examples illustrate how to determine compatibility of DG not in limited packs:

Example I

Compatibility of PIPERAZINE (UN 2579) and ALUMINIUM CHLORIDE SOLUTION (UN 2581)

Class 8

Incompatible with Classes 2, 3 and 5.1 and 5.2 DG according to Compatibility Table

CG18

Chemical property: alkalis

CR5

Incompatible with CG1 – acids

Information

Meaning

Class 8

Incompatible with Classes 2, 3 and 5.1 and 5.2 DG according to Compatibility Table

CG1

Chemical property: acids

CR6

CR19

Incompatible with CG18 – alkalis

Incompatible with CG6 – cyanides

(1) According to the DG List, UN 2579 and UN 2581 are Class 8 DG.

(2) According to the compatibility table in 2.3.3.2.5, Class 8 DG are mutually compatible. Therefore, column 10 of the DG List shall be checked.

(3) For UN 2579, column 10 of the DG List states “CG18” (Alkalis) and “CR5” (Incompatible with CG1 – acids).

(4) For UN 2581, column 10 of the DG List states “CG1” (Acids), “CR6” (incompatible with CG18 – alkalis) and “CR19” (Incompatible with CG6 – cyanides).

(5) According to CG18 of UN 2579 and CR6 of UN 2581, UN 2579 and UN 2581 are incompatible.

Example II

Compatibility of SODIUM NITRATE (UN 1498) and MORPHOLINE (UN 2054)

UN 1498 SODIUM NITRATE

Information

Meaning

Class 5.1

Incompatible with Class 2, 3, 4.2, 4.3, 5.2 and 8 DG according to Compatibility Table

UN 2054 MORPHOLINE

Information

Meaning

Class 8

Incompatible with Classes 2, 3 and 5.1 and 5.2 DG according to Compatibility Table

(1) According to the DG List, UN 1498 is Class 5.1 DG and UN 2054 is Class 8 DG.

(2) According to the compatibility table in 2.3.3.2.5, Class 5.1 DG is incompatible with Class 8 DG.

(3) Therefore, UN 1498 and UN 2054 are incompatible.

Flowchart for Determining the Compatibility of DG