The Greenwash Guide, produced by Futerra Sustainability Communications, found that the number of complaints about green claims lodged with and upheld by the Advertising Standards Authority has doubled since 2004.
It also reveals only one of the top ten UK advertising agencies has a specific policy to avoid creating greenwash.
The Advertising Standards Authority's Annual Report 2007 published earlier this month showed a record number of complaints were made about green claims last year.
Futerra produced the guide in a bid to cut down on the amount of greenwash in advertising, as it says this could damage consumer confidence and slash spending on environmentally-friendly products, known as the green pound.
This could, in turn, reduce the incentive for companies to produce more eco-friendly products.
Solitaire Townsend, chief executive and co-founder of Futerra, told edie: "The green pound is crucial because the messages from consumers significantly outweigh the pressure that's brought to bear by NGOs and governments.
"Any damage to green consumption is a very worrying trend."
Most of the greenwash was caused by poorly thought out campaigns and negligence, rather than deliberate attempts to deceive consumers, researchers found.
Miss Townsend said: "From what we have seen, there's only small amounts of malicious greenwash to mislead the consumer, and often that's quite easy to spot."
The guide includes tips to help companies avoid making exaggerated claims, and a spotters guide to classic signs for consumers who want to wise up.
It can be downloaded for free here.
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