The future of fumigation

Published 11th August 2022 | Articles

If a farmer from the 1970s was taken forward in time to a present-day farm, they would undoubtedly be taken aback by the changes to technology and farming practices.

However, if someone working in the fumigation industry was given the same snapshot of their profession 50 years later they would still recognise most of what they saw.

“The gas we use is a very old product which has been around for many, many years,” says Peter Woolley from Alpha Fumigation. “In terms of improvements to kit, there have been one of two things, such as airflow masks and self-contained respiratory breathing suits. But that’s about it – it’s really still quite an unsophisticated way of treating a product.”

Martin Cobbald, Director at Dealey Environmental Ltd, agrees. “The techniques we use have largely stayed the same since the 1970s – all that has changed is the amount of data that comes out of it and the amount of scientific knowledge you now need to have to apply it.

“As we’re coming up against the changing biology of pests we have to have the knowledge necessary to tweak levels; if you look at data tables from the 1980s you can see that bugs then were so much softer – they’ve got a lot harder, so we have to be really good at what we do.”

Spraying v gassing

Alpha Fumigation have been operating in the sector since 2011 covering Yorkshire and Suffolk. Specialising in fumigation and insecticide spray work, they use two different methods – spraying and gassing.

“If you spray with an insecticide, you will end up with a chemical residue on the product, which is allowable up to a certain level, but it is detectable,” Peter explains.

“Whereas it’s very difficult to detect if a product has been gassed, because it basically dissipates into the atmosphere.”

When it comes to treating cargoes for the export market, Peter says a lot of products earmarked with closer destinations, such as Antwerp and Ireland, will be sprayed because it’s been in store for a long period of time.

“If the cargoes are going further afield, let’s say to North Africa, then they tend to be gassed,” he adds.

Although the product label allows pulses to be sprayed, Peter can’t recall an instance where they have, as this product tends to be gassed.

“At the moment, we’re regularly gassing peas heading out to Japan,” he says.

Martin adds: “The main way of treating peas and beans is with an old wartime gas called phosphine, which was first used as a pesticide in 1948.

“Unless they’re classified as organic, in which case we use carbon dioxide and nitrogen.”

Martin started in the fumigation crew at Dealey Fumigation and went on to become managing director of the company nine years later. He took on the Managing Director role at Step Pest Control in 2016 which has since been amalgamated into Dealey Environmental.

“We can operate at every stage post-harvest, from farm level to transport level, be it on ships or in containers, and that tends to be where the bulk of our work focuses,” he explains. And then we also fumigate for the processers – we’re doing 1,600 tonnes worth of beans and peas this week.”

Fumigation is not used as a preventative measure, as regulations are in place stipulating that pesticides should never be used if nothing is present.

“Keeping stores cool, below 15 degrees, and in fairly stable and clean conditions will help prevent significant issues,” he says.

New threats

Peas and beans are an interesting case for fumigators, Martin says, because they have a pest which is found in both the field and in storage, which is rare.

“Usually you have pre-harvest and post-harvest pests, which are completely different species posing problems at different parts of the chain,” he explains.

“However, the bruchid beetle and pea and bean weevil get involved at the field stage and then emerge later on in storage as well.”

Martin adds that the team has also identified a new pest that is affecting beans – the Chinese bruchid beetle.

“It’s just started coming in,” he says. “It’s a storage pest for beans which can re-infest stored pulses. We don’t usually have them in this country, but we’ve seen more and more of them over the past couple of years.

“However, we’ve seen no evidence of resistance in Chinese Bruchid to the gasses we use which is positive.”


Martin is unfailingly positive, but even he admits that the industry didn’t have an easy time of it during Brexit.

“We have a couple of very embedded, mature lines of supply that have been very Brexit resilient,” he says.

“The only issues we’ve had concern regulation, where things have had to be re-registered post-Brexit.

“It cost us £120,000 in total to get phosphine re-registered. It takes a lot of expertise and therefore a lot of money to rewrite everything that was in the European regulatory documents, especially when the Europeans have been slightly spiteful about the whole situation and held onto a lot of their data, meaning it had to be redone.

However, Martin is optimistic about the future.

“More people are growing pulses and this looks likely to keep increasing, and we’re starting to hear talk about protein extrusion plants. We don’t have one in Britain yet, which is surprising considering how big the plant-based market is becoming.

“It looks as though our little island is going to be more independent in the future, which means there will be more industry kept in-house.”

Peter shares this optimism, although he admits the business has encountered challenges regarding supply and prices increasing.

“We’re having to order gas, particularly the product that is preferred by Morocco, Tunisia and Egypt for beans, between four and six months in advance, which means trying to second guess the market,” he says. “We’re having to carry high stocks just to make sure we can respond if and when there is that demand, which isn’t easy for a small company.

“We can source chemicals in 48 hours. However, the prices have just been put up by another 6%.”

Martin adds that although there are challenges, he believes the fumigation industry is less vulnerable than other sectors.

“The risks our customers have to endure with price volatility, international markets and geo-politics are much more difficult than the risks we face,” he explains.

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