TT Talk - Hazardous gases in containers

Possible dangers to those whose job is to enter freight containers either during or at the end of a multi modal journey have been known for a long time. One specific danger that has been concentrated on arose from the use of fumigants. Fumigants are used worldwide to prevent the spread of pests, to keep the cargo in good shape or prevent the goods against unwanted insects. Different kinds of fumigants are used, one being Aluminium Phosphide; if this fumigant is not applied properly or there is too much of it, residue can remain.

The fact is that a freight container is a very enclosed space with, in most instances, no ventilation at all so dangerous concentrations of toxic gases might remain. However, it has gradually been realised that there are other possible contaminants as well - those coming from the cargo itself. The International Safety Panel of ICHCA International published one of its Safety Briefing Pamphlets (BP#20) on such dangers in 2006, and has since revised it in 2010. In collaboration between the TT Club and ICHCA, a 'pocket card' was published (IIL/4) in early 2010 providing guidance on the dangers of entry into freight containers.

The aim of the recent Dutch initiative was to ensure that compliance with legislation on hazardous gases in import containers was monitored and its first report covers 1,033 containers that were checked between 1 October 2008 and 1 October 2009. Four methods were used to select the containers for sampling - random selection (250), based on regulations concerning hazardous substances (150), based on customs regulations, cargo type and country of origin (500) and finally a selection based exclusively on cargo type and country of origin.

Excessive concentrations of hazardous gases were found in a total of 106 containers - about 10% of the total.

Be aware of this risk; if in doubt, stop and ask for advice!

It was established that 17 of this total had been actively fumigated with toxic substances at concentrations exceeding the limit values. Only one of those containers bore a warning sign as required by the IMDG Code. The others neither had any such sign nor any reference to fumigation in the accompanying documentation. The hazardous gases found in the remaining 89 containers were released by the cargo and those most often found were in descending order toluene, benzene, 1,2-dichloroethane, methyl bromide, phosphine, formaldehyde and chloropicrin. Whilst the percentage found to have airborne contaminants was low, it was, nevertheless, significant and the message is clear to those whose employees are likely to have to enter freight containers during or at the end of their overseas journeys.

Following questions in the Netherlands Parliament, a number of Government Departments in that country have combined to implement an agreement on the joint monitoring of hazardous gases in import containers. This arose from a number of incidents and the aim was to inspect 1,000 containers per year. This close attention to one aspect of the dangers of enclosed spaces has a parallel with the perennial hazards of enclosed spaces on ships, including cargo and related spaces, with which the maritime world has been grappling recently at IMO.