The gap between what consumers think they are getting when they purchase organic products and what they are actually getting is larger than most people think.

A Consumer Reports National Research Center survey found that 84 percent of United States consumers purchase organic food, with 45 percent of those purchasing organic food once a month or more.

A majority of consumers believe that labeling food "organic" means it doesn't contain pesticides (81 percent) or antibiotics (66 percent.)

The truth is, only 100 percent organic labeling means products contain only organic ingredients. "Certified organic" means 95 percent of the product is organic, while the other 5 percent can come from a USDA-approved list of ingredients.

The USDA grants five-year exemptions to allow synthetic material in organic products without notifying the public.

The majority of the public disagrees -- 91 percent of consumers believe organic produce should not contain any pesticides, while 61 percent believe organic produce should not contain any antibiotics.

Some notable exceptions include the use of streptomycin on labeled organic apples and pears, artificial ingredients in chicken feed and synthetic materials in aquaculture, as "organic" fish haven't been defined.

Read More:

• Survey: Consumers Might Read Organic Label Differently Than Organic Standards Board (Food Safety News)
• What you actually get when the package is labelled "Organic" (Quartz)