Industrial-strength weedkillers and pesticides are being made widely available to untrained amateur gardeners on eBay and other websites, experts have warned.

Both pesticide manufacturers and anti-pesticide campaigners have voiced alarm about the unrestricted sale of super-strong pesticides to unqualified buyers in online marketplaces.

So-called ‘professional pesticide products’ – aimed at farmers and groundskeepers – contain chemicals in concentrations that cannot legally be used by anyone untrained in their safe use. But there is no law against selling these products to unqualified buyers.

Pesticide manufacturers believe some vendors are exploiting this loophole to deliberately market professional products to amateurs on eBay and other websites. Environmental campaigners warn that, without proper training, amateurs using these products pose a risk “to their own health and the environment”.

Unearthed has seen a written briefing by the Crop Protection Association – which represents some of the world’s largest pesticide companies – which describes the online sale of professional pesticides to amateurs as an “area of significant concern”.

Amateur gardeners could misapply these products, posing a risk to their own health and the environment

The briefing says professional products available on eBay and other websites – particularly those containing the weedkiller glyphosate – are “frequently listed or advertised with amateurs clearly as the target audience using words such as ‘Very Strong’, or ‘Strongest’, or ‘Super Strength’”.

It states: “They often do include the word ‘professional’ however there is a belief that this is being used to highlight that the product is better or ‘stronger’ than the products typically available for amateur gardeners.”

Unearthed identified several sellers on eBay that advertise professional glyphosate products in this way, including some eligible for the company’s “premium service” reserved for the sellers who meet eBay’s “top rated performance standard”.

Landmark court case

The news comes just weeks after a California jury ruled that the glyphosate-based weedkiller Roundup contributed to a former schools groundskeeper developing terminal cancer. Roundup manufacturer Monsanto – which has been ordered to pay Dewayne Johnson $289m (£226m) damages – has said it will appeal against the ruling.

Searches by Unearthed in recent weeks found that professional strength glyphosate products were widely available on eBay.co.uk.

These findings follow a previous Unearthed investigation which revealed that illegal and mislabeled pesticides were easy to buy on eBay’s UK site, triggering a trading standards authority investigation.

The authority said it would follow up with eBay on the issue of professional pesticides, after being alerted to it by Unearthed.