Updated: Sep 30, 2022
According to the Mayo Clinic, "organic" refers to how farmers grow and process agricultural products, such as fruits, vegetables, grains, dairy products, and meat. Organic farming practices are designed to meet specific goals such as enhancing soil and water quality and reducing pollution.
Organic farming practices are prohibited from using synthetic fertilizers to add nutrients to the soil, sewage sludge as fertilizer, most synthetic pesticides for pest control, irradiation to preserve food or to eliminate disease or pests, genetic engineering used to improve disease or pest resistance, or to improve crop yields. On the contrary, organic crop farming materials or practices may include plant waste left on fields (green manure), livestock manure or compost to improve soil quality, plant rotation to preserve soil quality, and interrupt cycles of pests or disease. Organic crop farming may use cover crops that prevent erosion when parcels of land are not in use, plow into the soil to improve soil quality, and mulch to control weeds. Organic crop farming may also use predatory insects or insect traps to control pests and certain natural pesticides. They also claim only a few synthetic pesticides are approved for organic agriculture; they claim they are used rarely and only as a last resort in coordination with a USDA organic certifying agent (1).
According to the U.S. Department of Agriculture (USDA), organic or USDA-certified organic foods are cultivated and handled according to federal guidelines, influencing factors such as soil quality, animal raising techniques, pest and weed control, and additives. Organic producers depend on natural substances and physical, mechanical, or biologically farming practices for the most total capacity possible (2).
Crops can be called organic if certified to have grown on soil with no prohibited substances for three years before harvest. Banned substances comprise mainly synthetic fertilizers and pesticides. Still, when a grower uses an artificial substance to formulate a particular purpose, the substance must be approved according to criteria first and then examined for its potential effects on human health and the environment (2). Unfortunately, USDA-certified organic also allows a limited number of non-organic substances that may be used in or on processed organic products (3).
As per 7 CFR 205.601(m) of The National List of Allowed and Prohibited Substances, USDA-certified organic regulations also allow synthetic inert ingredients, as classified by the Environmental Protection Agency (EPA), for use with nonsynthetic substances or synthetic substances used as active pesticide ingredient in accordance with any limitations on the use of such substances (4).
The USDA-certified organic regulations authorize natural substances while restricting synthetic substances in farming methods. The National Organic Standards Board (NOSB) is intended to advise the National Organic Program (NOP) by law on which substances should be allowed or prohibited in farming techniques. These groups comprise dedicated volunteers selected by the Secretary of Agriculture, board members including organic growers, handlers, retailers, environmentalists, scientists, USDA-accredited certifying agents, and consumer advocates (2).
Synthetic Substances Allowed In USDA-Certified Organic Produce
USDA-certified organic regulations allow the following synthetic substances to be used as algicide, disinfectants, and sanitizer, including irrigation system cleaning systems:
Hypochlorous acid generated from electrolyzed water
Ozone gas for use as an irrigation system cleaner only
Peracetic acid for use in disinfecting equipment, seed, and asexually propagated planting material
Sodium carbonate peroxyhydrate (4)
USDA-certified organic regulations allow the following synthetic substances to be used as herbicides, and weed barriers, as applicable:
Soap-based herbicides for use in farmstead maintenance and ornamental crops
Mulches such as newspaper or other recycled paper, without glossy or colored inks, plastic mulch, and covers (petroleum-based other than polyvinyl chloride, biodegradable biobased mulch film) (4)
USDA-certified organic regulations allow newspapers or other recycled paper without glossy or colored inks, a synthetic substance such as compost feedstocks. As animal repellents, the USDA-certified organic rules allow soaps and ammonium as a large animal repellant only but restrict contact with soil or the edible portion of a crop, again, a synthetic substance (4).
USDA-certified organic regulations allow the following synthetic substances to be used as insecticides, including acaricides or mite control:
Ammonium carbonate may be used as bait in insect traps only, with no direct contact with crop or soil
Aqueous potassium silicate, but the silica used in the manufacture of potassium silicate must be sourced from naturally occurring sand
Boric acid may be used as structural pest control but may not directly contact the organic food or crops
Copper sulfate for use as tadpole shrimp control in aquatic rice production is limited to one application per field for 24 months
Lime sulfur, including calcium polysulfide
Horticultural oils to narrow range oils as dormant, suffocating, and summer oils
Sucrose octanoate esters in accordance with approved labeling
Pheromones for insect management
Vitamin D3 for rodenticide
Ferric phosphate and elemental sulfur for slug or snail bait (4)
USDA-certified organic regulations allow the following synthetic substances to be used for plant disease control:
Aqueous potassium silicate, but the silica used in manufacturing potassium silicate, must be sourced from naturally occurring sand.
Fixed coppers such as copper hydroxide, copper oxide, and copper oxychloride, including products exempted from EPA tolerance, provided that copper-based materials are used in a manner that minimizes accumulation in the soil and shall not be used as herbicides
Copper sulfate, but the substance must be used in a manner that minimizes the accumulation of copper in the soil
Horticultural oils to narrow range oils as dormant, suffocating, and summer oils
Peracetic acid for use to control fire blight bacteria and is also permitted in hydrogen peroxide formulations as allowed in at a concentration of no more than 6% as indicated on the pesticide product label
Polyoxin D zinc salt (4)
USDA-certified organic regulations allow the following synthetic substances to be used for plant or soil amendments:
Aquatic plant extracts other than hydrolyzed, but the extraction process is limited to the use of potassium hydroxide or sodium hydroxide; the solvent amount used is limited to that amount necessary for extraction
Humic acids but naturally occurring deposits, water, and alkali extracts only
Lignin sulfonates such as chelating agents and dust suppressants
Magnesium oxide may be used only to control the viscosity of a clay suspension agent for humates
Magnesium sulfate is allowed with a documented soil deficiency
Micronutrients include soluble boron products, sulfates, carbonates, oxides, or silicates of zinc, copper, iron, manganese, molybdenum, selenium, and cobalt but may not be used as a defoliant, herbicide, or desiccant.
Liquid fish products can be pH adjusted with sulfuric, citric, or phosphoric acid.
such as B1, C, and E
Squid byproducts from food waste processing only
Sulfurous acid for on-farm generation of substance utilizing 99% purity elemental sulfur (4)
USDA-certified organic regulations allow ethylene gas to regulate pineapple flowering as plant growth regulators and odium silicate for the tree fruit and fiber processing as floating agents in post-harvest handling. USDA-certified organic rules allow hydrogen chloride for delinting cotton seeds for planting during seed preparations. As production aids, the USDA-certified regulations allow microcrystalline cheese wax for use in log-grown mushroom production. Still, it must be made without either ethylene-propylene co-polymer or synthetic colors (4).
Synthetic Substances Prohibited In USDA-Certified Organic Produce
Despite this very long list of things they allow in our organic produce, the list of non-synthetic substances that are prohibited is much shorter and includes the following:
Ash from manure burning
Calcium chloride, brine process is natural and prohibited for use except as a foliar spray to treat a physiological disorder associated with calcium uptake
Potassium chloride, unless derived from a mined source and applied in a manner that minimizes chloride accumulation in the soil
Mined sodium fluoaluminate
Sodium nitrate, unless the use is restricted to no more than 20% of the crop's total nitrogen requirement
Tobacco dust (nicotine sulfate) (4)
The Dirty Dozen
According to USA Today, nearly 70 percent of non-organic produce sold in the United States contains pesticide residues. More than 90 percent of samples, including strawberries, apples, and leafy greens, tested positive for residues of two or more pesticides (5). In 2004, the Environmental Working Group (EWG) released its first annual list of fruits and vegetables said to contain the most pesticides; the group calls this list the Dirty Dozen (6). Many health and nutrition enthusiasts believe the dirty dozen is the holy grail of organic produce.
Over 90 Percent of Non-Organic Citrus Fruits Contain Fungicides Linked to Cancer and Hormone Disruption (7).
The Environmental Working Group (EWG) released a complete list of Shopper's Guide to Pesticides in Produce, which you can look over here. The Environmental Working Group (EWG) Dirty Dozen List for 2021 included the following produce:
Kale, collards, mustard greens
Bell and hot peppers
NOTE: A small amount of sweet corn, papaya and summer squash sold in the United States is produced from genetically modified seeds. Buy organic varieties of these crops if you want to avoid genetically modified produce (8).
Fresh produce, such as fruits and vegetables, are integral to a healthful and nourishing diet. Nonetheless, many crops retain potentially contaminated with pesticides that are detrimental to your overall health and wellbeing, even after washing, peeling, or scrubbing, which the USDA does before sampling each item. Since pesticide contamination differs by crop, it is paramount to understand which items are most or least contaminated, especially if you cannot afford to purchase strictly organic produce. Furthermore, fresh produce that is most contaminated, such as spinach, strawberries, and other Dirty Dozen fruits and vegetables, still have heightened levels of pesticides in their frozen forms (9).
It is also important to mention that the USDA does not sample and test for all pesticides used in produce production. Due to pre-harvest drying agents, high levels of glyphosate have been discovered in several grains and beans, such as oats and chickpeas. In 2019, the USDA collected hundreds of samples of oats and chickpeas. Roundup, also known as glyphosate, is the most heavily used pesticide in the United States. and is used on these crops, yet the USDA has not analyzed them for glyphosate (9).
If this is allowed with organic produce, just imagine what is allowed in non-organic produce.