Yes, apple skins carry pesticide residues more often than almost any other fruit or vegetable. In testing of conventional apples, residues of multiple pesticides were identified in about 94% of samples. Apples rank ninth on the Environmental Working Group’s 2025 “Dirty Dozen” list, and they’re also treated with additional chemicals after harvest to extend shelf life.
That said, the presence of residues doesn’t automatically mean danger. What matters is how much is there, what kind it is, and what you can do about it.
What’s Actually on the Skin
Conventional apple orchards use a range of pesticides throughout the growing season: insecticides to kill bugs, fungicides to prevent mold and rot, and herbicides to manage weeds. Some of the most frequently detected residues on apples include thiamethoxam (an insecticide), carbendazim (a fungicide), and tebuconazole (another fungicide). In one large market survey, thiamethoxam and carbendazim each showed up in over 60% of apple samples tested.
Not all of these chemicals sit on the surface. Pesticides fall into two categories that matter here. Contact pesticides, like captan and fludioxonil, are fat-soluble and tend to lodge in the waxy outer layer of the apple skin. They don’t penetrate much deeper. Systemic pesticides, like tebuconazole, boscalid, and cyprodinil, are water-soluble and get absorbed into the plant’s tissue. These can move through the skin and into the flesh of the apple, which means peeling or washing won’t fully remove them.
How Much Gets Into the Flesh
A study published in the Journal of Agricultural and Food Chemistry tested how deeply two common pesticides penetrated into apples after 24 hours of exposure. About 20% of the systemic fungicide thiabendazole had moved past the skin and into the apple’s flesh. For the contact insecticide phosmet, only 4.4% penetrated beyond the surface. The skin acts as a partial barrier, but it’s not a perfect one, especially for systemic chemicals designed to be absorbed by the plant.
This is worth keeping in perspective. The amounts involved are measured in nanograms per square centimeter. Regulatory agencies like the EPA set maximum residue limits for each pesticide on each food, and these limits include wide safety margins. The federal tolerance for captan on apples, for example, is 25 parts per million, while malathion is set at 8 parts per million. Most tested apples fall well below these thresholds.
How Well Washing and Peeling Work
Plain water is surprisingly ineffective. One study found that conventional washing with water (about 1.5 liters per fruit) had essentially no measurable effect on pesticide residue levels in apples. The waxy coating on apple skin repels water, and the pesticides embedded in that wax layer resist being rinsed away.
Baking soda does considerably better. Soaking apples in a solution of about one teaspoon of baking soda per two cups of water removed surface residues of thiabendazole completely in 12 minutes and phosmet in 15 minutes. The mild alkalinity of baking soda helps break down the chemical structure of many common pesticides. It won’t reach the portion that has already absorbed into the flesh, but it handles what’s sitting on and in the skin far more effectively than tap water alone.
Peeling is the most effective single step. Removing the skin reduced pesticide levels by anywhere from 24% (for deeply penetrating compounds like carbendazim) to 100% (for surface-dwelling chemicals like tebuconazole and thiodicarb). For most pesticides, peeling removes the vast majority of residue.
The Nutritional Cost of Peeling
Apple skin is where most of the fruit’s best nutrients are concentrated. A raw apple with its skin contains up to 332% more vitamin K, 142% more vitamin A, and 115% more vitamin C compared to a peeled apple. It also delivers about 20% more calcium and 19% more potassium. Up to 31% of an apple’s total fiber sits in and just beneath the skin, along with most of its polyphenols, the plant compounds linked to reduced inflammation and heart disease risk.
Peeling an apple to avoid pesticides means giving up a significant chunk of what makes the apple nutritious in the first place. For most people, a better strategy is to wash apples with baking soda water and eat them whole.
Organic Apples vs. Conventional
Organic apples carry far fewer synthetic pesticide residues. In one school meal study, no pesticide residues were detected in any organic apple samples, while 94.4% of conventional apple samples contained residues of multiple pesticides. Organic farming does permit certain naturally derived pesticides like sulfur and copper compounds, but these are used less frequently and tend to leave lower residue levels.
If your concern is specifically about synthetic pesticide exposure, organic apples are a meaningful upgrade. They’re also more expensive. A practical middle ground: buy organic for apples you’ll eat with the skin on, and don’t stress as much about conventional apples that go into pies or sauces where you peel them first.
A Simple Cleaning Routine
- Skip plain water rinsing. It makes almost no difference for pesticide removal on apples.
- Soak in baking soda solution. Mix roughly one teaspoon of baking soda into two cups of water. Submerge your apples for 12 to 15 minutes, then rinse under tap water.
- Rub while rinsing. Gently scrubbing the surface helps dislodge residues trapped in the wax layer.
- Dry before storing. Moisture left on the surface can encourage mold growth in the fridge.
This routine removes the vast majority of surface pesticide residues. It won’t eliminate the small fraction that has already been absorbed into the flesh, but that amount is typically well within established safety limits. For most people, eating washed, unpeeled apples remains a net positive for health.