But just how truthful are those ads?
A 'Yes on I-522' ad states the measure "simply labels food sold in grocery stores if it's genetically engineered."
But it's not that simple. There's a huge list of foods that are exempt -- even if they have genetically altered ingredients, such as cows milk, cheese and meat.
Their claim that the changes won't cost consumers a dime is true only if it requires a change in labeling. But their claim will be false if, as predicted, food manufacturers change their formulas to non-genetically engineered ingredients.
An independent study by the Washington Research Council, but paid for by opponents of I-522, says the cost of eliminating GMO's would be passed on to consumers.
"The cost of the initiative for a family of four would be upwards from $450 a year," said Kriss Sjobom with Washington Research Center.
Meanwhile, the initiative's opponents are spending $10 million to defeat it.
"The food labeling regulations in I-522 conflict with national standards and make no sense," former state agriculture director Dan Newhouse said in a 'No on I-522' ad. While farmer Nicole Berg claims in the ad "it's a complex misleading food labeling proposal that no other state requires."
That part is true -- Washington would be the only state in the union with the new labeling law. California tried passing it last year, but it narrowly failed.
"We have a right to know if our food has been genetically engineered," the Yes on 522 ad states.
What's not in either ad campaign is the fact that the 'yes' side is supported mainly by the organic foods groups and that big food makers such as Monsanto and DuPont are backing the 'no' campaign.
Supporters of I-522 are suing to get the opponents ads off the air. But for now they're staying put with the vote coming up in just seven weeks.