Chain Reaction: Handling a problem of dangerous gases in shipping containers from Asia to Europe
Results of Air measurements on a container arriving in Europe was shown to contain a harmful mixture of more than 90 different substances, highlighting the importance of technology to reduce exposure to hazardous substances.
Almost two years ago, a study published in the Journal of Occupational Medicine and Toxicology found that between 10% and 20% of all containers arriving at European harbours were shown to contain volatile toxic substances above the exposure limit values. Transporting more than 70% of all international freight, container ships represent most of the freight cargo. Freight on board ships in containers is frequently disinfected by use of toxic fumigants. Common fumigants include Chloropicrine, Methyl bromide, Ethylene dibromide, Sulfuryl fluoride and Phospine. Other sources of toxic substances in container transport are packaging material and the cargo itself.
The combination of fumigants, product preservatives, limited container ventilation, hot temperatures and long transit times, can result in a lethal toxic cocktail released when the container doors are opened and represent a major threat to port and transport workers, customs officials, warehousemen, store employees and even consumers.
Case Outline: Handling a problem of dangerous gases in shipping containers
A container shipment of automotive components from China was delivered to TradeLink’s cross-dock facility in Bremen, Germany and presented with a strong odour. Contamination of the container was suspected that contained 49 palettes of automotive components. The suspicion of hazardous substances was enough for TradeLink to act and commission external experts to perform analysis and assessment of the cargo to identify the hazardous risk and source materials responsible for the emissions.
Prior to inspection of the palettes, the container was quarantined in a secure open area to allow ventilation over several days. Three random sample palettes of cardboard boxes containing the automotive parts were tested for a wide spectrum of highly volatile organic substances. The automotive parts were individually packed into to trays, stacked and covered with a plastic sheet before being packed into cardboard boxes and palletized. The significance being, that tests were performed on all elements of the packaging, including the product itself.
Basis of Air Sampling Assessments
The opening and unloading of freight containers can be associated with health risks and were dangerous gases and vapours can lead to respiratory stresses. In order to obtain an overview of the health assessment of the substances detected, the occupational exposure limit values (AGW values) are referred to.
According to the Ordinance on Hazardous Substances, the AGW value is the limit for the time-weighted average concentration of a substance in the air at the workplace in relation to a given reference period. It indicates the maximum concentration of a substance that is not expected to cause acute or chronic adverse health effects on workers in general.
Recommended course of action
In this case, Air analyses of the container and cargo conducted over several hours showed that a harmful substance mixture consisting of more than 90 different individual substances was present. In the individual substance assessment, it was determined that exceedances of the AGW values were not present.
Based on measurements of all materials, it was concluded that primarily the palette and the product tray were the strongest emission sources. The automotive parts did not emit any relevant solvent emissions.
The recommended action called for the palette, and especially the packaging (cardboard, plastic sheet, tray), to be removed and from which the automotive parts should be unpacked. The palettes and packaging material would be removed from the storage hall and disposed of in accordance with legal regulations. The automotive parts would be quarantined in specially commissioned packaging while our client liaised with their supplier.
Preventative Measures & Technology
All supply chain partners have a duty of care when it comes to the safe handling and stripping of freight containers and lessons must be learned and shared from cases arising.
TradeLink’s partners operate to strict guidelines for safe procedures that include knowledge and awareness among staff and use of appropriate personal protective equipment, devices and expertise in the handling of cargo and suspected contaminated cargo.
The wide variety of potential contaminants represents a technological challenge to those responsible for handling and testing containers across the supply chain. At present there is no single portable instrument available to detect all types of relevant hazardous substances at sufficient sensitivity. Current technologies reported in the Journal of Occupational Medicine and Toxicology include:
- Photo ionization detector (PID) for volatile organic compounds (VOC)
- Infrared (spectra) only for sulfuryl difluoride
- Sensors (CO, CO2, O2, PH3)
- Colorimetrical gas detector or indicator tubes, mainly for methyl bromide + 1,2-dichloroethane, benzene, toluene, chloropicrin, styrene, xylene.
As technology solutions progress to be able to simultaneously analyse a large number of target compounds in a short space of time, this will in turn increase the effectiveness of the assessment and reduces risk to supply chain staff.
Meanwhile lessons learned must be passed up the supply chain for corrective action. In this case, a change of supplier packaging has been introduced as well as random testing of incoming product from Asia.
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