Allowed and Prohibited Substances in Organic Farming

Organic farming and production has strict guidelines on what substances can and cannot be used. This ensures that organic products are produced sustainably and healthily.

Understanding USDA Organic Standards and the National List

The USDA organic standards ensure that farming remains natural by mostly allowing natural substances and restricting synthetic (man-made) ones. Exceptions to these rules are clearly laid out in the National List of Allowed and Prohibited Substances.

The National Organic Standards Board (NOSB), which includes farmers, scientists, and other experts, plays a crucial role in deciding what makes it onto this list. They assess each substance's safety, environmental impact, and compatibility with organic principles.

Quick Guide to the National List:

Synthetic Substances: These are generally not allowed unless specifically listed as permitted. Only those that are proven safe and necessary for organic farming are included.
Natural Substances: Typically allowed unless they are explicitly restricted or banned due to safety reasons.

Key Takeaway for Farmers: Always check the National List to see which synthetic substances are approved and which natural ones are restricted. This ensures you stay compliant with organic standards and maintain your organic certification.

Below is a simplified list of substances currently allowed and prohibited in organic farming and production. We've done our best to make this information easy to understand, but for a more detailed look, please refer to the official National List of Allowed and Prohibited Substances.

CROPS

LIVESTOCK

PROCESSED GOODS

Allowed

Synthetic Substances Allowed in Organic Crop Production

7 CFR 205.601

Disinfectants, Algicides, and Sanitizers

Alcohols:
- Ethanol
- Isopropanol
Chlorine Materials (for pre-harvest use, cleaning irrigation systems, and edible sprout production under EPA label directions):
- Calcium Hypochlorite
- Chlorine Dioxide
- Hypochlorous Acid (generated from electrolyzed water)
- Potassium Hypochlorite (for irrigation)
- Sodium Hypochlorite
Copper Sulfate:
- Limited to one application per field every 24 months in aquatic rice systems, with application rates that do not increase soil copper levels beyond baseline over an agreed timeframe.
Hydrogen Peroxide
Ozone Gas:
- Used only as an irrigation system cleaner.
Peracetic Acid:
- For disinfecting equipment, seeds, and asexually propagated planting materials, permissible in hydrogen peroxide formulations up to 6% concentration.
Soap-based Algicides/Demossers
Sodium Carbonate Peroxyhydrate:
- Restricted to approved food uses as per the product label.

Herbicides and Weed Barriers

Soap-Based Herbicides:
- For farmstead maintenance (e.g., roadways, ditches, building perimeters) and ornamental crops.
Mulches:
- Newspaper/Recycled Paper: Without glossy or colored inks.
- Plastic Mulch and Covers: Petroleum-based, excluding polyvinyl chloride (PVC).
- Biodegradable Biobased Mulch Film: Must be produced without organisms or feedstock derived from excluded methods.

Compost Feedstocks

Newspapers or other recycled paper, without glossy or colored inks.

Animal Repellents

Soaps, ammonium (for use as a large animal repellent, no soil or edible crop contact).

Insecticides and Mite Control

Ammonium Carbonate:
- Used only as bait in insect traps, no direct crop or soil contact.
Aqueous Potassium Silicate:
- Silica sourced from naturally occurring sand, used as a foliar spray to suppress fungi and must not be used as a soil amendment.
Boric Acid:
- For structural pest control, not in direct contact with organic food or crops.
Copper Sulfate:
- Used for tadpole shrimp control in aquatic rice production, limited to one application per field every 24 months without increasing soil copper levels.
Elemental Sulfur
Lime Sulfur (including calcium polysulfide)
Horticultural Oils:
- Narrow range oils used as dormant, suffocating, and summer oils.
Insecticidal Soaps
Sticky Traps/Barriers
Sucrose Octanoate Esters:
- Used in accordance with approved labeling.

Insect Management

Pheromones

Rodenticide and Bait

Vitamin D3
Ferric Phosphate:
- Used as slug or snail bait.
Elemental Sulfur

Plant Disease Control

Aqueous Potassium Silicate:
- Same restrictions as listed under insecticides.
Fixed Coppers (e.g., copper hydroxide, copper oxide, copper oxychloride):
- Used in a way that minimizes soil accumulation, not as herbicides.
Hydrated Lime
Lime Sulfur
Horticultural Oils:
- Same as listed under insecticides.
Peracetic Acid:
- For controlling fire blight bacteria, permissible in hydrogen peroxide formulations up to 6%.
Potassium Bicarbonate
Elemental Sulfur
Polyoxin D Zinc Salt

Plant or Soil Amendments

Aquatic Plant Extracts:
- Limited to potassium hydroxide or sodium hydroxide extraction.
Elemental Sulfur
Humic Acids:
- Must be from natural deposits, water and alkali extracts only.
Lignin Sulfonate:
- As a chelating agent and dust suppressant.
Magnesium Oxide,
Magnesium Sulfate (with documented deficiency)
Micronutrients (excluding nitrates or chlorides)
Liquid Fish Products
Vitamin C
Vitamin E
Squid Byproducts
Sulfurous Acid.

Plant Growth Regulators

Ethylene Gas:
- For pineapple flowering.
Fatty Alcohols:
- For sucker control in organic tobacco.

Floating Agents in Postharvest Handling

Sodium Silicate:
- For tree fruit and fiber processing.

Seed Preparations

Hydrogen Chloride
- For delinting cotton seeds.

Production Aids

Microcrystalline Cheesewax:
- For use in log-grown mushroom production, without synthetic colors or ethylene-propylene copolymers.
Paper-based Crop Planting Aids:
- Must use virgin or recycled paper without glossy or colored inks.

Synthetic Substances Allowed in Organic Livestock Production

7 CFR 205.603

Disinfectants and Sanitizers

Alcohols:
- Ethanol: Used as a disinfectant and sanitizer, prohibited as a feed additive.
- Isopropanol: Used solely as a disinfectant.
Chlorine Materials (used for disinfecting and sanitizing facilities and equipment):
- Calcium hypochlorite
- Chlorine dioxide
- Hypochlorous acid (generated from electrolyzed water)
- Sodium hypochlorite
  - Note: Residual chlorine levels must not exceed limits under the Safe Drinking Water Act.
Peroxyacetic/Peracetic Acid (CAS #79-21-0):
- For sanitizing facilities and equipment.
Phosphoric Acid:
- Allowed as an equipment cleaner with no direct contact with organically managed livestock or land.
Activated Charcoal (CAS #7440-44-0):
- Must be from vegetative sources.

Medical Treatments

Aspirin:
- Approved for reducing inflammation in health care use.
Atropine (CAS #51-55-8):
- Restricted to veterinary use with specific withdrawal times for meat (56 days) and milk (12 days).
Biologics:
- Vaccines.
Butorphanol (CAS #42408-82-2): Restricted to veterinary use with specified withdrawal times.
Calcium Borogluconate and Calcium Propionate
- For treatment of milk fever only.
Chlorhexidine (CAS #55-56-1):
- For medical procedures and as a teat dip under veterinary supervision.
Flunixin (CAS #38677-85-9):
- Follows doubled FDA withdrawal periods under NOP standards.
Glycerin:
- Approved as a livestock teat dip, produced through the hydrolysis of fats or oils.
Iodine, Magnesium Hydroxide, and Magnesium Sulfate:
- Various uses under veterinary direction.
Mineral Oil:
- For treatment of intestinal compaction, not as a dust suppressant.
Nutritive Supplements:
- Injectable supplements of trace minerals, vitamins, and electrolytes, under veterinary order.
Oxytocin:
- For postparturition therapeutic applications.
Parasiticides:
- Fenbendazole and Moxidectin: Specific restrictions on use in dairy and slaughter stock.
Sodium Chlorite, Acidified:
- As a teat dip treatment for organic livestock.
Tolazoline (CAS #59-98-3) and Xylazine (CAS #7361-61-7):
- Restricted to veterinary use with specific withdrawal periods.

External Treatments and Local Anesthetics

Copper Sulfate and Elemental Sulfur:
- For treatment of livestock and housing.
Formic Acid (CAS #64-18-6):
- Used as a pesticide in honeybee hives.
Lidocaine:
- As a local anesthetic with specific withdrawal times.
Lime, Hydrated:
- For external pest control.
Oxalic Acid Dihydrate:
- For apicultural use as a pesticide.
Zinc Sulfate:
- For hoof and foot treatments only.

Feed Additives and Supplements

Methionine Variants:
- Allowed in organic poultry production with specified limits per ton of feed.
Trace Minerals and Vitamins:
- Approved for enrichment or fortification when FDA approved.

Synthetic Non-Organic Substances Allowed as Ingredients in Organic Processed Goods Production

7 CFR 205.605

Antimicrobial Agents and pH Regulators

Acidified Sodium Chlorite:
- Used for antimicrobial food treatment; must be acidified with citric acid only.
Potassium Lactate & Sodium Lactate:
- Used only as antimicrobial agents and pH regulators.

Leavening Agents

Ammonium Bicarbonate:
- For use as a leavening agent only.
Ammonium Carbonate:
- For use as a leavening agent only.
Sodium Acid Pyrophosphate (CAS # 7758-16-9):
- For use only as a leavening agent.

Vitamins, Mineral, and Nutritional Enhancements

Ascorbic Acid
Calcium Citrate
Ferrous Sulfate:
- For iron enrichment or fortification when required by regulation.
Nutrient Vitamins and Minerals:
- In accordance with 21 CFR 104.20, Nutritional Quality Guidelines for Foods.

Sanitizers and Disinfectants

Chlorine Materials:
- For disinfecting and sanitizing food contact surfaces and equipment up to maximum labeled rates.
Calcium Hypochlorite
Chlorine Dioxide
Hypochlorous Acid (generated from electrolyzed water)
Sodium Hypochlorite
Hydrogen Peroxide
Ozone
Peracetic Acid/Peroxyacetic Acid (CAS # 79-21-0):
- For use in wash and/or rinse water as per FDA limitations and as a sanitizer on food contact surfaces.
Phosphoric Acid:
- For cleaning of food-contact surfaces and equipment only.

Food Processing Aids

Alginates
Calcium Hydroxide
Calcium Phosphates (monobasic, dibasic, and tribasic)
Carbon Dioxide
Collagen Gel:
- As casing, may be used only when organic collagen gel is not commercially available.
Ethylene:
- Allowed for postharvest ripening of tropical fruit and degreening of citrus.
Glycerides (mono and di):
- For use only in drum drying of food.
Low-Acyl Gellan Gum
Magnesium Stearate:
- For use only in products labeled “made with organic (specified ingredients or food group(s)),” prohibited in products labeled “organic.”
Potassium Carbonate
Potassium Citrate
Potassium Hydroxide:
- Prohibited for use in lye peeling of fruits and vegetables except for peeling peaches.
Potassium Phosphate:
- For use only in products labeled “made with organic (specified ingredients or food group(s)),” prohibited in products labeled “organic.”
Silicon Dioxide:
- Permitted as a defoamer; allowed for other uses when organic rice hulls are not commercially available.
Sodium Citrate
Sodium Hydroxide:
- Prohibited for use in lye peeling of fruits and vegetables.
Sodium Phosphates:
- For use only in dairy foods.
Sulfur Dioxide:
- For use only in wine labeled “made with organic grapes,” provided that total sulfite concentration does not exceed 100 ppm.
Tocopherols:
- Derived from vegetable oil when rosemary extracts are not a suitable alternative.
Xanthan Gum

Filtering Aids

Activated Charcoal (CAS #s 7440-44-0; 64365-11-3):
- Only from vegetative sources; for use only as a filtering aid.
Cellulose (CAS #9004-34-6):
- For use in regenerative casings, powdered cellulose as an anti-caking agent (non-chlorine bleached) and filtering aid. Microcrystalline cellulose is prohibited.

Natural Non-Organic Substances Allowed as ingredients in Organic Processed Goods Production

7 CFR 205.605. & 205.606

Acids

Citric Acid:
- Produced by microbial fermentation of carbohydrate substances.
Lactic Acid
L-Malic Acid (CAS # 97-67-6)
Tartaric Acid:
- Must be made from grape wine.
Glucono delta-lactone:
- Note: the production of d-glucose with bromine is not allowed.

Gelling Agents and Stabilizers

Agar-agar
Carrageenan
Gellan Gum (CAS # 71010-52-1):
- Only high-acyl form is permitted.
Pullulan:
- For use only in tablets and capsules for dietary supplements labeled “made with organic (specified ingredients or food group(s))”.

Enzymes and Microorganisims

Animal Enzymes:
- Rennet (animal-derived)
- Catalase (from bovine liver)
- Animal lipase
- Pancreatin
- Pepsin
- Trypsin
Enzymes:
- Must be derived from edible, nontoxic plants, nonpathogenic fungi, or nonpathogenic bacteria.
Microorganisms:
- Any food-grade bacteria, fungi, and other microorganisms are allowed.

Minerals and Salts

Calcium Carbonate
Calcium Chloride
Calcium Sulfate:
- Must be mined.
Magnesium Chloride
Magnesium Sulfate:
- Must be from nonsynthetic sources.
Potassium Chloride
Potassium Iodide
Sodium Bicarbonate
Sodium Carbonate

Processing Aids and Filtration Materials

Attapulgite: Used as a processing aid in the handling of plant and animal oils.
Bentonite
Diatomaceous Earth: Allowed only as a food filtering aid.
Kaolin
Perlite: For use only as a filter aid in food processing.

Flavors and Preservatives

Flavors:
- Nonsynthetic flavors may be used when organic flavors are not commercially available, must not be produced using synthetic solvents, carrier systems, or artificial preservatives.

Gases

Nitrogen:
- Must be oil-free grade.
Oxygen:
- Must be oil-free grade.

Waxes and Other Compounds

Waxes:
- Nonsynthetic, such as wood rosin.
Carnauba Wax
Yeast:
- Must be organic if used in products labeled as “organic” for human consumption.
- Nonorganic yeast permissible when organic yeast is not commercially available.
- Growth on petrochemical substrates and sulfite waste liquor prohibited.
- Smoked yeast must use a documented nonsynthetic smoke flavoring process.

Food Coloring from Agricultural Sources

Must not be produced using synthetic solvents, carrier systems, or any artificial preservatives.

Beet Juice Extract Color: Derived from Beta vulgaris L., excluding sugar beets.
Beta-Carotene Extract Color: Derived from carrots (Daucus carota L.) or algae (Dunaliella salina).
Black/Purple Carrot Juice Color: Derived from Daucus carota L.
Chokeberry, Aronia Juice Color: Derived from Aronia arbutifolia (L.) Pers. or Aronia melanocarpa (Michx.) Elliott.
Elderberry Juice Color: Derived from Sambucus nigra L.
Grape Skin Extract Color: Derived from Vitis vinifera L.
Purple Sweet Potato Juice Color: Derived from Ipomoea batatas L. or Solanum tuberosum L.
Red Cabbage Extract Color: Derived from Brassica oleracea L.
Red Radish Extract Color: Derived from Raphanus sativus L.
Saffron Extract Color: Derived from Crocus sativus L.

Food Ingredients and Additives

Casings:
- From processed intestines.
Celery Powder
Cornstarch (Native)
Fish Oil (Fatty acid CAS #'s: 10417-94-4, and 25167-62-8):
- Stabilized with organic ingredients or ingredients on the National List, §§ 205.605 and 205.606.
Fructooligosaccharides (CAS # 308066-66-2)
Gelatin (CAS # 9000-70-8)
Glycerin (CAS # 56-81-5):
- Must be produced from agricultural source materials and processed using biological or mechanical/physical methods as outlined in § 205.270(a).
Gums (Water-extracted only):
- Arabic, Guar, Locust bean, Carob bean.
Inulin—oligofructose enriched (CAS # 9005-80-5)
Lecithin—de-oiled
Orange Pulp, Dried
Orange Shellac—unbleached (CAS # 9000-59-3)
Pectin (non-amidated forms only)
Potassium Acid Tartrate

Natural Products

Seaweed, Pacific Kombu
Tamarind Seed Gum
Tragacanth Gum (CAS # 9000-65-1)
Wakame Seaweed (Undaria pinnatifida)

Prohibited

Natural Substances Prohibited in Organic Crop Production

7 CFR 205.602

What to Avoid

Ash from Manure Burning:
- Prohibited due to potential contamination.
Arsenic:
- Toxic substance that is not allowed.
Lead Salts:
- Toxic substance that is not allowed.
Potassium Chloride:
- Unless derived from a mined source and applied in a way that minimizes chloride accumulation in the soil.
Rotenone
Calcium Chloride:
- Only allowed as a foliar spray for calcium deficiencies.
Sodium Fluoaluminate:
- Limited use due to environmental and health concerns.
Sodium Nitrate
Strychnine:
- Toxic and completely banned.
Tobacco Dust (Nicotine Sulfate):
- Contains nicotine sulfate, which is prohibited.