Truck and Track Summer 2023 Summer 2023 Truck and Track 63 DANGEROUS GOODS In this issue, our Dangerous Goods Columnist Ali Karim BSc FRSC provides advice for the dangerous goods logistics operator to prepare for the hot Summer predicted in Europe this year. With climate change upon us, many sectors have to adapt to hotter Summers. This is especially relevant to operators working with Dangerous Goods (ADR and IMDG) ensuring they are prepared. This precautionary advice is provided in good faith as Dangerous Goods Operators all have a ‘Duty of Care’. Advice or guidance can be obtained from the organisation’s DGSA, as this month’s column is purely to raise awareness of the problems that may arise due to elevated Summer temperatures on material that falls within ADR (Road Carriage) and IMDG (Sea) as well as Multi-Modal. Drivers and Depot Staff Please ensure your staff remain well hydrated during a heat wave and advise your teams that although they may wish to wear short-sleeve shirts and shorts for comfort, when working with Chemicals, bare-skin can pose problems by getting Dangerous Goods inadvertently on the skin. Apart from the obvious risk of burns from Class 8 (Corrosive), Classes 5.1 (Oxidising Agents) and 5.2 (Organic Peroxides) or skin adsorption of Class 6.1 (Toxic) and Class 6.2 (Biologically Infectious) - there is also the risk of dermatitis from Class 9 (Environmental/Miscellaneous Hazard) among others hazards and risks. It is an imperative to ensure staff members are dressed appropriately for the assigned task – including correct Personal Protective Equipment (PPE) – which can be determined by internal (or external) risk assessment. The Effect of Heat and Direct Sunlight on Chemicals An understanding of the Physical Chemistry terms ‘Flash Point’, ‘Autoignition Temperature’ and ‘Fire Point’ is essential when temperature elevation is a factor or risk. When Class 3 (Flammable Liquids) and Class 4 (Flammable and Reactive Solids) are exposed to Direct Sunlight (UV), they may become heated and could combust (catch fire). This is especially serious for Packing Group/Transport Category I. These following terms should be understood: The flash point of a volatile material is the lowest temperature at which vapours of the material will ignite, when given an ignition source and Oxygen from atmospheric air (which contains 21% O2). The flash point may sometimes be confused with the autoignition temperature, which is the temperature at which the vapour ignites spontaneously without an ignition source. The fire point is the lowest temperature at which vapours of the material will keep burning after being ignited and the ignition source removed. The fire point is higher than the flash point because, at the flash point, more vapour may not be produced rapidly enough to sustain combustion. Neither flash point nor fire point depends directly on the ignition source temperature, but it may be understood that the ignition source temperature will be considerably higher than either the flash or fire point. The Hazards of Monomers and Polymerisation With Polymeric materials such as Styrene, Vinyl Acetate Monomer etc, as additional heat or Ultra Violet Radiation (e.g. by Direct Sunlight) can cause polymerisation. When monomers undergo polymerisation, additional heat is generated by the exothermic reaction which can cause fire and then explosion due to ‘thermal runaway’. Polymeric Materials are often stabilised with Inhibitors such as 4-tert-butyl-catechol although high heat (and UV sunlight) can compromise the efficacy of the inhibitor in preventing a polymerisation reaction. There are certain products governed by ADR and IMDG that are very problematical with elevated temperatures, and these are managed by refrigerated storage or refrigerated transport. It is therefore an imperative that your DGSA checks the SDS (Safety Data Sheet) to ensure they are stored under the aegis designated by the consignor/manufacturer. Site Planning and UV Sunlight Please ensure that no hazardous or combustible materials are placed under direct sunlight, for the heat can make flammable material reach (or exceed) flash points, and a spark, or even UV heating of the material, could cause ignition/explosion; as well as vapour pressure build-up which can result in rupturing drums, IBCs, cans etc. Often, ‘yard’ or FLT operators will prepare a load for a truck or trailer in advance to loading. It is critical that, if material is taken from a warehouse, it is kept in a shaded area (to avoid direct sunlight) prior to vehicle loading. If a container or closed vehicle unit is unloaded, the doors are opened carefully and the doors opened fully to allow the unit sufficient ventilation, prior to unloading procedures. Metal containers shipped under IMDG or ADR may get hot inside due to the (highly thermally conductive) exterior metal being exposed to direct UV sunlight. IBCs, drums and cans may ‘bow’/leak as well as PRVs being released, so there could be a build-up of vapour or even leaking liquid with the unit. Ensure hazardous material is kept away from combustible materials and that you have checked your fire risk assessments, fire alarms, run (and documented) fire drills and trained staff appropriately to the risks presented by hot weather. ADR and IMDG Preparedness for Summer 2023 by Ali Karim Ali Karim TRUCK & TRAILER SOLUTIONS WELCOME TOALLPORTS GROUP