The study published in the Journal Agricultural and Food Chemistry found baking soda was the best method for removing pesticide residues.
Speaking to CNN, author Lili He, a food scientist at the University of Massachusetts, Amherst said: "We want to see whether or not the factory level (of washing) is already effective [at removing pesticides].”
The study compared bleach, tap water and baking soda and found a teaspoon of baking soda into two cups of water made pesticides physically easier to remove from apples.
However, no method was 100 per cent effective.
“We have pretty good control of pesticide amount,” He tells CNN. “That doesn’t ensure that there’s no risk at all. What we really can do is reduce the risk [by washing].”
But not everyone agrees.
Dr Motoko Mukai, a toxicologist in the Department of Food Science at Cornell University's College of Agriculture and Life Sciences who was not involved in the study.
"It all depends on the chemical properties of the pesticide, so it's not one fit for all," said Mukai, who tends to wash produce with tap water.
She added that washing produce is important but there's "not a clear winner."