These days, it’s hard to know what to look for at the grocery store. With lots of information out on the internet about nutrition and food safety, there’s a lot to take into account when you buy fruits and vegetables. Locally grown? In season? Organic? Free trade?

More than all of this, big food companies and supermarkets don’t always give you as much information as you’d like to have when you’re making a decision about something as important as feeding your family!

Today, we’ll give you insider hacks for how to know more about the produce you’re buying. Best of all, it’s right there hidden in plain sight.

The secret is anything fancy; it’s something you see on just about every piece of fruit and on the ties around vegetables. We’re talking about the little barcodes and numbers that cashiers use to ring your purchases up.

These numbers are called PLU (price look up), so they help supermarkets keep track of their inventories and speed up the check-out process. But what most people don’t know is that these simple codes can also give you important information about what kind of produce you’re looking at.

1. Conventional – four numbers in the PLU

Let’s imagine that you’re buying the most popular fruit in America—no it’s not apples, it’s bananas. Most bananas that we eat are the sweet yellow variety called Cavendish. They all share the same basic code: 4011. If you see this code, the standard for most bananas, what you’re looking at is a conventional banana.

What does conventional mean? Conventionally grown produce often receives chemical fertilizers to increase the size and accelerate the growth of the fruit. Farmers can also use synthetic insecticides, herbicides, and fungicides to protect the crop. But all this can come at the expense of your health and the environment.

Because bananas are grown on large plantations with no other crops, they require lots of pesticides. These pesticides harm the workers who harvest them and the people who live nearby. Thanks to the banana’s thick peel, however, you don’t have to worry about absorbing them yourself.

2. Genetically Modified – five numbers in the PLU, starting with the number 8

While conventional foods can be grown in a way you might want to avoid, another class of fruits and vegetables are even more controversial. We’re talking about Genetically Modified Organisms (GMOs).

These foods have been scientifically re-engineered by adding genes from other plants or sometimes even animals to bring out certain characteristics, such as resistance to herbicides or extra productivity.

Americans are already consuming a lot of GMO crops, oftentimes without even realizing it, as Time Magazine reports. Ninety percent of corn and soybean fields in the United States are growing modified crops, and these can end up getting eaten by animals that will become meat or put in processed foods.

While there’s no definitive evidence that GMO foods cause health problems, many people are afraid of such a new, unregulated technology. So if you see 84011, for example, than your bananas have been genetically modified.

3. Organic – five numbers in the PLU, starting with the number 9

So if you’re worried about the safety of your family and the planet, organic foods are a great option. Organic foods aren’t treated with chemical pesticides and fertilizers and often have higher nutrition levels. Not sure if a piece of produce is organic?

If you look at the PLU code once again, you’ll see the four digits identifying the item plus the number 9 at the beginning. So for instance, organic bananas should be labelled 94011.

Knowing this is a great way to steer yourself toward healthier food as well as help out the farmers who grow it!

If you’re interested in knowing more about which conventional foods are the most dangerous, the Environmental Working Group makes two helpful lists. The “Dirty Dozen,” including family favorites such as strawberries, grapes, and tomatoes, features produce that tend to get grown with lots of chemicals! So beware.

Thankfully, the “Clean 15,” featuring beloved fruits and vegetables like avocados, pineapples, and kiwis, are foods that don’t require much treatment when grown conventionally.

Now you know how to double-check what kind of produce you have! Whatever the signs in the produce section say, don’t forget to look at the PLU!