"We've been taking calls and receiving emails from concerned customers who now feel they have been sold toxic and dangerous extinguishers," Mr Richdale said.
The Fire Watch rep worked for a company which sold water foam extinguishers in competition with the ABE dry powder extinguishers, he said.
"The multipurpose ABE extinguisher is the only one approved to be used on paper, textiles, plastics and wood (A), burning fuels (B) and electrical (E) fires," he said.
"With all types of extinguishers there is the need for proper training in their use and that doesn't entail firing the extinguisher above and around your head in a small room as demonstrated on the Fair Go programme.
"Used properly, the fire is quickly put out and the operator doesn't come into contact with the powder, nor do they get covered in powder," Mr Richdale said.
He applauded the show for highlighting the fact that not all companies were operating in good faith or were members of the FPA.
He said the FPA had been investigating a scam that had been going on since 2009.
It involved one man going into a store and saying his extinguisher needed a service, taking that cylinder away and charging the store owner $140 a time.
"He's then been going into another store, spinning the same story and taking their extinguisher and replacing it with the one he's removed from the previous store," Mr Richdale said.
But he said the TV programme was not balanced. He said the issue that should have been addressed was the "rip-off merchant" who had been operating around the country.
