The ins and outs of dangerous goods

The ins and outs of dangerous goods

For those who are new to the transportation and handling of dangerous goods (DG), the rules and regulations surrounding these activities can be confusing. FOCUS speaks to William Goibaiyer, adviser and consultant for Hazchemwize, about some of the frequent concerns of new operators.

The rules governing dangerous goods transportation have, over the last few years, grown far more stringent. While obviously hazardous substances – such as petrol – were previously classified as dangerous goods, packaged goods (that are sometimes equally dangerous) often weren’t.

This has now changed, however. Today, common household goods like adhesives, aerosols, batteries, cosmetic chemicals, paint and pharmaceuticals are all classified as dangerous goods. And, as a result of this, the list of official dangerous goods has increased from around 750 substances a few years ago to over 2 500 today.

Moreover, the modern rules governing the transportation of these materials are very strict. For instance, before a vehicle is allowed to legally move dangerous goods, it must have the correct documentation, including Tremcard, dangerous goods placards, a dangerous goods declaration, a dangerous goods permit and a dangerous goods vehicle licence (category D registration).

And all of this can often be confusing to transport operators who are new to the industry. With this in mind, FOCUS asked William Goibaiyer, an adviser and consultant for Hazchemwize, to help us cover some of the basics.

What exactly are dangerous goods?
Generally speaking, dangerous goods are substances that are potentially dangerous to people, property and the environment. The term includes substances that are explosive, flammable, spontaneously combustible, water reactive, oxidising, toxic and corrosive.

What is the difference between dangerous goods and hazardous substances?
Dangerous goods and hazardous substances are classified according to different criteria. Dangerous goods are classified on the basis of the immediate physical or chemical effects that they can cause such as fire, corrosion and poisoning. Hazardous substances are classified only on the basis of potential health effects – especially in the workplace.

Can you explain the different terms often associated with dangerous goods?
Firstly, every substance has a UN number. This is a four-digit number assigned by the United Nations to universally identify dangerous goods. Secondly, every substance has a proper shipping name. This is a standard name given to dangerous goods for transport purposes that can allow anyone to instantly identify a particular substance. Also, every substance has a class. Dangerous goods are grouped into one of nine classes according to the most significant hazard presented by the goods. Importantly, many substances also possess a “sub-risk”. Where dangerous goods present more than one hazard, the less significant hazard is termed a sub-risk.

Finally, dangerous goods are also assigned packaging groups (PG), depending on the level of danger that the goods represent. Groups one, two and three represent high, medium and low danger respectively.

What are the different classes of dangerous goods?
Dangerous goods are grouped into nine different classes, according to the most significant risk presented by the goods. For instance, if a substance falls into class one, it is explosive in nature. Similarly, if it falls in class three, it is a flammable liquid.

As I said, however, if a substance poses more than one hazard it is assigned a class on the basis of the most significant hazard and allocated one or more subsidiary risks (sub-risks), based on the other potential hazards.

Detailed information on the classification of dangerous goods according to the various classes can be obtained from Hazchemwize. They are classified as per hazard class:

•  Class 1 – Explosives
•  Class 2 .1 – Flammable gases
•  Class 2.2. – Non-flammable non-toxic gases
•  Class 2.2 (sub-risk 5.1) – Oxidising gases
•  Class 2.3 – Toxic gas
•  Class 3 – Flammable liquids
•  Class 4.1 – Flammable solids
•  Class 4.2 – Substances liable to spontaneous combustion
•  Class 4.3 – Substances that in contact with water emit flammable gases
•  Class 5.1 – Oxidising substances
•  Class 5.2 – Organic peroxides
•  Class 6.1 – Toxic substances
•  Class 6.2 – Infectious substances
•  Class 7 – Radioactive material
•  Class 8 – Corrosive substances
•  Class 9 – Miscellaneous dangerous goods and articles

As an operator, how will I know if chemicals supplied to me are classified as dangerous goods or combustible liquids?

Your supplier should be able to give you this information. This information should also be available from the label on the container or from a substance’s material safety data sheet (MSDS).

Why is it important for companies to comply with dangerous goods regulations?
In addition to the obvious fact that these regulations exist for the purpose of  protecting people’s lives and property, complying with the rules also makes good financial sense. A company like Hazchemwize can ensure compliance of a rigid dangerous goods vehicle for under R10 000. If an accident occurs and it is discovered that a vehicle wasn’t compliant, it can cost the operator hundreds of thousands, if not millions.

How should dangerous goods placards be used properly?
Placards are far too often not a true reflection of the load that is on the truck. Many vehicles simply display “mixed load” placards when they are clearly not actually transporting a mixed load.  If a vehicle is used to carry different substances at different times, its placards should be changed for every trip. Importantly, drivers should be trained as prescribed in regulation 280 and SAQA unit standard 123259 to display placards that give a true reflection of the load. Drivers have to know how and when to change a vehicle’s placards.

How will I know if different dangerous goods can be stored together?
Two or more dangerous goods are deemed compatible if their interaction does not result in a harmful reaction such as a fire or explosion, or in the creation of flammable, toxic, or corrosive vapours. If goods are not compatible, they must be stored together in a manner that will not allow them to come into contact.

Compatibility charts can be used as an aid in determining if two classes of dangerous goods are compatible. The SANS DG Codes, IATA and IMDG Codes contain a matrix for “segregation of dangerous goods”. If the dangerous goods are deemed to be incompatible, then measures need to be taken to segregate the incompatible goods.

Careful consideration has to be taken when deciding to convey dangerous goods as the information is complex and detailed.

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