SINCE first being introduced to international trade in 1956 the shipping container has seen a remarkable increase in importance. In 1968 fewer than one million containers were shipped around the world, by 2016 this had increased to 182m.
More than 90% of items shipped internationally use shipping containers. The shipping container has profoundly changed global trade by facilitating reliable and cheap transportation of goods. This, in turn, has had far-reaching consequences. On the positive side it has driven down the price of items. On the downside there has been the environmental impact with an increase in carbon dioxide emissions. The growth in the packing and unpacking of shipping containers has presented hazards to both employees and employers for example:
- Hazardous fumes – fumigants used for pest control, off gassing from products shipped in the containers;
- Manual handling – heavy lifting;
- Falling objects – due to shifts in the contents due to transport, falls of containers in container stacks.
Where a hazard is identified, elimination is the primary goal. If elimination is impossible, the hazard must be controlled as practically as possible to minimise risk to workers. Safe Work Australia has developed a series of information sheets to provide practical guidance for Australian workers to manage health and safety risks associated with unpacking shipping containers, including exposure to hazardous chemicals, for example fumigants and solvents. Suggestions by Safe Work Australia to eliminate or minimise exposure of workers to hazardous chemicals in shipping containers include using barriers and warning signs as well as providing workers with personal protective equipment.
In 2011, Safe Work Australia conducted research in Melbourne investigating the presence of residual chemicals in shipping containers. They surveyed 76 containers and found airborne hazardous chemicals in 74 of the 76 containers. The most common hazardous chemical residues identified are fumigants and solvents. Toluene (92.1%) and xylene (73.7%) were the most commonly identified airborne hazardous chemicals in the shipping containers tested. When workers were interviewed during this research, it was identified those exposed to the airborne hazardous chemicals were more likely to report symptoms of memory loss, asthma, irritation of the eyes, dryness of the mouth and dryness of the throat.
In addition to the health effects from exposure to these chemicals, solvents are highly flammable and cause fire and explosion risks when exposed to heat, sparks or a naked flame. The combined impact of health effects and fire risks associated with solvent-based materials in shipping containers increases the risk of sick days and staff turnover, WorkCover claims, increased insurance risk, specialised risk and safety training and litigation all of which are indirect costs.
Promoting better practices and training of staff to recognise and reduce the impact of residual chemical exposure from shipping containers must be a high priority for empty container parks. This represents minimisation of risk. However, consideration must be given to eliminating airborne hazardous chemicals from solvent-based paints that are widely used to upgrade the interior of shipping containers.
Hazardous chemicals in paint
It is a requirement to display notification of fumigation and a dangerous goods placard for solvents on the exterior of shipping containers that alert workers to potential risks from airborne hazardous chemicals. It is often overlooked that the products used to coat the interior of shipping containers can contribute to off gassing and subsequent inhalation risks. Indeed, of the five non-fumigant hazardous chemicals identified in the Safe Work Australia research, all are common raw materials found in solvent based, quick dry paints used for spraying the interior walls and ceilings of shipping containers. Interestingly, it is not required to placard a container that has had solvent-based paint sprayed on the interior when the outgassing of hazardous chemicals from these solvent based paints, toluene and xylene were the two most commonly detected airborne contaminants in shipping containers.
Over the past decade there has been increased emphasis on sustainability by the shipping industry, with a large focus on emissions reductions and carbon footprint, for example Maersk Low Carbon Future, CMA-CGM Corporate Social Responsibility Policy and IMO 2020. The issues faced by the shipping industry to make operations more sustainable and environmentally friendly are both short-term and long-term challenges. Long-term challenges will require significant investment on the behalf of ship owners, container owners and port operators. There are some shorter-term strategies that can be undertaken affordably to improve sustainability and worker safety.
The most immediate strategy is a switch from solvent-based to waterborne coatings. The introduction of waterborne coatings into the container industry first started back in 2010. Since then the use of waterborne coatings for the coating of newbuild containers has been mandatory from April 2017.
One of the biggest challenges presented to the container building factories in switching from solvent-based to waterborne paints was meeting the application process criteria, which is more involved for waterborne than for solvent-based.
Solvent-based paints were used in the container manufacturing industry for a reason: they are far easier to apply and more forgiving if there are shortcomings in the application process and more tolerant of cold weather. It was noted there were significant costs associated with switching from solvent-based to waterborne application processes for container manufacturers, including additional heating, venting and dehumidification, there was an increase in power consumption of up to 60% to facilitate the use of waterborne coatings.
Solvent-based enamel paints
Trends in the paint industry indicate that since the early 1990s solvent-based enamel paints have been banned in Europe in architectural coatings, however, they are still used in Australia today. By 2000 low VOC architectural coatings had become mainstream. By 2010 the benefits of low VOC and ultra-low VOC paints are being recognised in the architectural sector. While these benefits are applicable to water-based industrial coatings, like those that could be used on shipping containers, this transition has not occurred on a large scale in Australia with a focus on fast turnaround which is achieved using fast evaporating solvents.
The use of water-based coatings in the Australian shipping container maintenance and repair industry should be investigated with priority to improve health and safety for workers charged with carrying out upgrades, reducing the risk of exposure to solvent-based airborne hazardous chemicals. On top of this there are the associated environmental benefits that help shipping lines meet their environmental policy targets as well as meeting consumer preferences for sustainable products and services.
* Dr Brendan McAuliffe is managing director at Aquio and has a commercial interest in water-based coatings.
This article appeared in the August 2019 edition of DCN Magazine