"I just don't think you get a second chance with that kind of thing," Miss Warren said.
"Safety is paramount and we certainly would not risk that at all. No questions asked. It was not an option to have them this year. Absolutely not."
Miss Warren said the association was "really confident" in the contractors they had chosen for Saturday's A&P show and had done "quite an extensive level of due diligence on them".
"We have visited large-scale events similar to ours and seen them in action, walked through a number of health and safety things with them, looked at how they operate, we've even had them here on our grounds prior to the show.
"We've ticked all of the boxes and we're confident in what we're going to provide."
Miss Warren said when she first became association manager late last year, she had to "hit the ground running" to help organise the show.
"We had a Mini A&P Show with St Patrick's school last Friday and the kids came and had a demonstration and taste of what to expect from our show on Saturday.
"So that was really great to see the key pieces of equipment in action and how it all works with our contractors from a safety perspective."
New to the show this year is an under 5s area and a parents room.
Gate to Plate event manager Gretchen Saulbrey said she was surprised people did not automatically assume another contractor would be used in this year's show.
"So we've done quite a comprehensive announcement on Facebook to make sure people are very clear that there's no way that we're using them," she said. "This is just about bringing the elephant in the room out and assuring people that our priority is to provide a safe environment for their families."