Licensees have been warned of a possible scam following reports that at least one company has been using underhand tactics to sell air cleaning equipment.
One licensee in Hull was told during a telephone call last month that failing to install a company's equipment would lead to prosecution.
Trade leaders have warned licensees not to install equipment without consulting the Atmosphere Improves Results (AIR) initiative, which has been working with the government and pub trade to implement a voluntary charter.
The charter is not compulsory and there is currently no law forcing licensees to install air-cleaning equipment. Even proposals for an Approved Code of Practice on smoking in the workplace would not make it compulsory to use aircleaners.
Allan Spencer, licensee of the Master's Bar in Hull city centre, was called last month. He said: "A woman said she was calling to see if I knew that it was going to be illegal not to have air cleaners when the new legislation was brought in.
"I said as far as I knew from what I had read they were not going to be compulsory and she hung up on me. She sounded like she was reading from a script and had been phoning round."
Oliver Griffiths from AIR said: "The charter is not about air cleaning. The guidance is firstly to get a pub's ventilation level over a minimum level and use of air cleaners is just to improve comfort levels after that. There are no pieces of kit out there that are compulsory."
Under the trade's voluntary charter on smoking in pubs, licensees are advised to use signage to inform customers of the smoking policy in the pub and make use of no-smoking areas and ventilation where necessary, with the use of air-cleaners optional for those who want to further improve comfort levels for customers.
Griffiths added: "There are certain areas where licensees are getting calls like this. We have heard of other examples in the North West."
Tony Payne, chief executive of the Federation of Licensed Victuallers Associations, said: "I would say to any licensee who is approached to buy any product, whether it be air cleaners or something else, to seek advice before agreeing to or signing anything.
"If they are telling you that you need a product or service by law you should check first - if not with your trade association then with your local trading standards department to see if the company is reputable."
Nick Bish, chief executive of the Association of Licensed Multiple Retailers, said: "We all need to decide on charter policies and implement them but it's an industry led initiative and we don't need rogue companies inventing spurious claims for their financial gain."
For more information on complying with the charter or advice on air cleaner manufacturers call AIR on 020 7482 0620.