Development of procedures for avoiding container handlers’ exposure to toxic chemicals

Not all freight containers have records of gases they contain, which exposes the container handlers to danger. Some of the logistics companies measure gas concentrations for all containers, but numerous companies pay attention only to containers marked having potentially dangerous gases. Recently, a major Finnish logistics company realized that their employees were in real danger by exposing to toxic gases when they open imported containers. To improve the situation, The Finnish Work Environment Fund and VTT Technical Research Centre of Finland Ltd together with Finnish Customs, Port of Helsinki and major Finnish logistics operators launched a research project aiming to provide instructions to relevant stakeholders on how the containers could safely handle.

In order to understand the current situation better, some background information is presented here. Containers coming especially from East Asia to Europe may have harmful mould, pests or rodents. In addition to harming the content of the container, East Asian species of animal do not usually belong to Europe and therefore they may cause ecological problems to local environment if they end up in Europe alive. Therefore the containers are often fumigated to poison unwanted animals and mould. Another problem is that the products or product packages may contain formaldehyde (used also for fumigants) and benzene compounds because the products are often packed too quickly after manufacturing without adequate dry off in factory.

The problem is not new and it has been recognized also earlier. However, the enlarging global trade, new places of cargo origins and the development of chemicals change the situation continuously. During the past few years, there have been several attempts to find out the extent of problems. In the port of Hamburg, the researchers took random sample of 2113 transport containers in 2006 (Baur et al., 2010). 70% of those containers had disinfectant gases or other industrial chemicals the amount that exceeds the allowed repetitive exposure for humans. One third of the containers had such amount of harmful gases that exceeds the limits for acute toxicity in breathing air. 0.6% of containers had life-threatening amounts of chemical residues.

The similar results were obtained in the project lead by Finnish customs, where 289 containers were opened in the harbour of Vuosaari, Finland in 2010. The project participants realized that the scale of gases found was so wide that it was impossible to guess beforehand what kind of gas the container may include. Surprisingly, most of the harmful gases found were industrial chemicals - not disinfectant. The results showed that the amount of toxic gases exceeded occupational health and safety amounts in 18% of the opened containers. In addition, breathing indoor air of two containers would have caused immediate mortal danger. One dangerous container had paper rolls, and the dangerous gas was carbon disulphide. Another dangerous container had mixed content and the dangerous gas was 1,2-dichloroethane. The other containers exceeding the allowed limits of gases contained for example oranges, wine, electronics, car, wooden toys and books.

International regulations exist regarding the use of fumigants and how to handle fumigated cargo. However, these regulations are seldom followed especially outside European Union. One notion from the research in Hamburg was that none of the inspected container had valid IMDG code that is required for all freight transport units having fumigated cargo. Only 4% of inspected containers had some kind of warnings related to fumigation of containers, but these markings were outdated or otherwise doubtful. When there are no warnings, the persons who open the containers, may not be aware of risks that the opening of the container may include. And the problem is not restricted to harbors as the containers are no longer always opened there; the container may be opened first time in logistics center or even in a retail store.

The use of 20 chemicals for transportation container fumigation has been reported. In addition, dozens of chemicals evaporating from cargo has been reported. There is an attempt to assess gas concentrations of transportation containers by using a range of gas detectors both before opening the container and after ventilation. However, measurement methods currently in use seem not to be reliable enough when assessing possible risk for working safety. In the worst case, incorrect measurement may endanger the safety of the person handling containers, when the person relies too much on measurements. International Maritime Organisation (IMO) recommends in its document MSC.1/Circ.1361, of 27 May 2010 (Revised Recommendations on the Safe Use of Pesticides in Ships Applicable to the Fumigation of Cargo Transport Units) that the gas measurements should be performed for at least two of the most commonly used fumigants: methyl bromide and phosphine. As an example of the possible methods of measurement, analysis tubes, detectors based on photoionization (PID) and personal alarms are mentioned. Few benefits and disadvantages of each method are also mentioned, but for example requirements for measurement areas or sensitivity are not presented. IMO’s document MSC.1/Circ.1361 also states that personal alarms exist to measure the oxygen concentration in the air. However, the fact that oxygen concentration seems to be at a correct level does not guarantee that containers are free of dangerous fumigants. Therefore, there is a need for common guidelines for the methods of measurement and sampling methods.

Finland is now aiming to improve working safety related to fumigated containers. The ongoing research project of VTT and The Finnish Work Environment Fund is called ‘Identification of the risk management ways of the gases which endanger industrial safety in containers’. The aim of the project is to improve work safety during the end part of logistic chains, including unloaders, custom officers, container cleaning etc. The project assesses commercial gas measurement devices, globally reported gas compounds with their properties, and measurement campaign of ventilation times in dense and not dense loaded containers in different ventilation circumstances. Project material will be available at the end of 2015.

By Ville Hinkka, VTT Technical Research Centre of Finland Ltd.

Baur X, Poschadel B, Budnik LT. (2010) High frequency of fumigants and other toxic gases in imported freight containers–an underestimated occupational and community health risk. Occupational & Environmental Medicine; Vol. 67, pp 207–212.

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