Jersey has become the first place in the British and Irish Isles to grant a licence for farmers to harvest hemp flowers for cannabis oil.

A former Royal Marine commando and two former colleagues will be the pioneers who process hemp for cannabidiol (CBD) extraction.

The trio hit upon the idea six years ago when they were working as firefighters in Jersey. They had developed a substance called Hempcrete, a fire-resistant sustainable building material made from the woody core of the hemp plant.

David Ryan, Jersey Hemp’s chief executive, said they were delighted to get the licence. “It will allow us to supply products made using CBD with clear British Isles provenance to retailers and direct to the public. The market for CBD products is growing rapidly as it becomes increasingly recognised for its nutritional benefits and for general wellbeing.”

Ryan said the company had been using CBD in some of its products but until Friday they had had to import it from outside the British and Irish Isles.

“The fact that we can produce the oil for ourselves legally here in Jersey will massively reduce our costs now that we don’t have to import CBD anymore,” the ex-soldier said. “We can do it ourselves under one roof and then sell directly into the UK and beyond. It was a no-brainer to get the licence given that we were using CBD oil up until now but from foreign hemp farms.”

Current estimates are that annual sales of CBD products are worth £300m and are expected to rise to just short of £1bn by 2025.

The licence will allow Ryan and his colleagues to produce an estimated 30 to 40 tonnes of dry hemp annually. About 3% to 5% of the yield from their 30-hectare (74-acre) organic hemp farm will be for CBD.

Lyndon Farnham, Jersey’s minister for economic development, tourism, sport and culture, said: “Extracting Jersey-produced CBD will allow the island to take its place in this fast-developing sector, supplying controlled and reliable CBD products with strong British Isles provenance. Jersey has real potential in this area, and the issuing of this licence signals our clear intent to position ourselves as a centre of excellence in CBD production, research, genetics and intellectual property.”

Last month, two hemp farmers in Oxfordshire destroyed 16 hectares of hemp crop because the Home Office said they were no longer allowed to harvest it for CBD oil.

The farmers, Patrick Gillett and Ali Silk, have launched a national campaign to have the decision reversed and to force the Home Office to grant licences to other British farmers who want to cultivate the crop for CBD oil and other extracts. The pair stressed that the CBD oil they extracted from hemp was well within the Home Office’s legal limit of 0.2% THC – tetrahydrocannabinol, the substance that produces a psychoactive high.

Ryan said he sympathised with the farmers who had to destroy their crops.

He said: “We’ve just cut out first hemp flowers today and it’s a great feeling to know we now can make our own oil. We will be harvesting them from now until October.”