Allowed & Prohibited Inputs

The following are lists containing some of commonly used substances that are allowedrestricted and prohibited in the CNG Program. This list is not exhaustive, but is meant to address some common questions.

Because certain substances are allowed for particular uses, but not others, this list is organized by use: Fertility and Soil Amendments, Plant Pests and Diseases, Weed Control, Livestock External Parasiticides, Livestock Feed Additives, and Livestock Health. (Download content as PDF.)

NOTE: Check the OMRI List for materials or products that are not listed below.
NOTE: While there are substances not listed under OMRI that would qualify for CNG use, any material listed by OMRI is allowed, with the exception of Rotenone and synthetic hydroponic nutrient solutions, which are prohibited.
NOTE: CNG allows the use of Paper Pot Transplanters.
NOTE: CNG allows the use of some biodegradable mulch products.
NOTE: If you are a flower grower, please review our Considerations For Flower Farmers page.

Jump to
Allowed Substances for Produce
   Fertility, Soil Amendments and Potting Mixes
   Plant Pests and Disease
   Weed Management and Miscellaneous
Allowed Substances for Livestock
   Livestock External Parasiticides
   Livestock Feed Additives
   Livestock Health
Restricted Substances for Produce
   Fertility, Soil Amendments and Potting Mixes
   Plant Pests and Disease
   Weed Management and Miscellaneous
Restricted Substances for Livestock
Prohibited Substances for Produce
   Fertility, Soil Amendments and Potting Mixes
   Plant Pests and Disease
   Weed Management and Miscellaneous
Prohibited Substances for Livestock
Additional Useful Resources


Allowed Substances for Produce

Fertility, Soil Amendments and Potting Mixes – Allowed

  • Animal and plant products such as:
    • bone meal
    • blood meal
    • feather meal
    • fish emulsion
    • alfalfa meal
    • soybean meal
    • molasses
    • neem
    • yucca
  • Compost – NOTE: for plant materials, must be heated to at least 131°F (55°C) for at least 3 days. For compost containing animal and plant materials, must be heated to 131°-170°F for at least 15 days and must be turned 5 times.
  • Compost tea – If the tea is made with finished compost and/or vermicompost with no additives, it can be applied without restriction. The addition of fish emulsion (or other additives like molasses, kelp, etc.) increases the risk of e. coli, listeria, and other harmful bacteria. Therefore, for applications of compost tea made with unfinished compost or raw manure and/or with additives* mixed in, CNG requires the same restrictions as raw manure – “It may only be (i) applied to land used for a crop not intended for human consumption; (ii) incorporated into the soil not less than 120 days prior to the harvest of a product whose edible portion has direct contact with the soil surface or soil particles; or (iii) incorporated into the soil not less than 90 days prior to the harvest of a product whose edible portion does not have direct contact with the soil surface or soil particles.”

    *If additives are mixed into finished compost tea and applied within an hour of mixing, the tea can be applied without restriction. Common additives include molasses, fish emulsion, kelp meal, etc.
  • Cover crops (must comply with the seed sourcing rule)
  • Rock minerals such as
    • High-calcium aglime
    • Dolomitic limestone
    • Rock phosphates
    • Gypsum
    • Sulfate of potash-magnesia
    • Mined potassium sulfate
    • Greensand or glauconite
    • Glacial gravel dust
    • Lava sand
    • Granite meal

Plant Pests and Diseases – Allowed 

  • Biological and microbial products such as
    • Bacilus thuringiensis(Able©, Bt©, Dipel©, Deliver©, Foray©)
    • Bacillus subtilis(Serenade©)
    • Beauveria bassiana (Mycotrol©)
    • Coniothyrium minitans(Contans©)
    • Myrothecium verrucaria(DiTera©)
  • Diatomaceous earth
  • Hydrogen Peroxide – for sanitizing or disinfecting
  • Insect Netting
  • Minerals such as
    • Elemental sulfur
    • Bicarbonate, potassium or sodium
    • Kaolin clay (Surround WP©)
  • Oils – narrow range petroleum, vegetable and fish oils are allowed for insect and pest control during the dormant and growing seasons
  • Pheromones and pheromone traps
  • Plant-derived substances such as
    • Neem
    • Pyrethrum
    • Caraway oil
    • Seed fennel
    • Corn gluten
    • Garlic
    • Quassia
    • Equisetum
    • Ryania
  • Row cover
  • Soaps (non-detergent) – Approved only for use on food crops (or equipment that come into contact with food crops) as a pesticide, fungicide, or algaecide. If used as herbicide, must be used only on non-food plants or around buildings, roadways, etc.
  • Streptomycin Sulfate and Tetracycline- only for fire blight in apples and pears
  • Sticky traps
  • Sulfur dioxide—underground rodent control only (smoke bombs)
  • Vitamin D3 (Cholecalciferol) – for rodent control

Weed Management and Miscellaneous – Allowed 

  • Mulch such as
    • Biodegradable plastic
    • Paper that is not glossy and does not have colored ink
    • Plastic mulch, so long as it is removed at the end of season
    • Straw, pine bark, wood chips and other plant based mulches that do not contain dyes or synthetic compounds
  • Paper pot transplanters
  • Plastic tarps, so long as they are removed at the end of season
  • Vinegar
  • Row cover and frost cloth
  • Weed barrier, so long as it is removed before it begins to deteriorate. Black plastic film must be removed at end of growing season.

NOTE for perennial growers: In perennial cropping systems, plastic mulch, weed barriers or row covers may be left in the field beyond the harvest season; however, these inputs must be removed before the plastic decomposes or breaks into pieces so that it is not possible to effectively remove all pieces from the soil.

Allowed Substances for Livestock

Livestock External Parasiticides – Allowed

  • Biologicals such as
    • Spinosad (NatularTM)
  • Botanicals such as
    • Pyrethrum (EquisectTM)
  • Essential oils such as
    • Citronella
    • Grapeseed
    • Jojoba
    • Lemongrass
    • Soybean oil

Livestock Feed Additives – Allowed

NOTE: these “may not be used in amounts above those needed for adequate nutrition and health maintenance at its specific stage in life. May not be used to stimulate growth or production.”

  • Diatomaceous earth
  • Fish meal
  • Kelp and seaweed meal
  • Minerals such as
    • Calcium
    • Carbon
    • Cobalt
    • Copper
    • Iron
    • Magnesium
    • Manganese
    • Phosphate
    • Potassium
    • Sodium
    • Sulfur
    • Zinc
  • Probiotics -some products can be fed routinely, while others can only be administered in case of illness
  • Salt
  • Synthetic Phosphorous
  • Synthenic Selenium
  • Yeast
  • Yucca

Livestock Health – Allowed

  • Aspirin – to reduce inflammation
  • Colostrum/Whey Antibodies
  • Essential oils such as
    • Eucalyptus
    • Lemon
    • Oregano
    • Thymol
  • Glycerin – “must be produced through the hydrolysis of fats or oils.”
  • Iodine – topical
  • Mineral oil – topical
  • Oxytocin
  • Probiotics – NOTE: some products can be fed routinely, while others can only be administered in case of illness
  • Vaccines

Restricted Substances for Produce

Fertility and Soil Amendments – Restricted

  • High salt content fertilizers such as sodium nitrate (Chilean nitrate), potassium sulfate, potassium chloride: must have a plan to limit salt accumulation and prevent excessive runoff. 
  • Raw manure – Raw, aged, or uncomposted manure, must be applied to the soil with adequate time before harvest of crops to make sure it breaks down entirely. This time period is 90 days where the edible portion of the crop does not come into contact with the soil (i.e. tree fruit, trellised tomatoes) and 120 days where the edible portion of the crop does come into contact with the soil (i.e. lettuce, carrots).
  • Synthetic micronutrients – use is permitted if there is a documented deficiency
    NOTE: Micronutrients— may only be used for fertility, and there must be a documented deficiency in the form of a soil or tissue test. Micronutrients made from nitrates or chlorides are prohibited.

    This applies to the following nutrients:
    • Soluble Boron products
    • Sulfates of zinc, copper, iron, manganese, molybdenum, selenium, and cobalt.
    • Carbonates of zinc, copper, iron, manganese, molybdenum, selenium, and cobalt.
    • Oxides of zinc, copper, iron, manganese, molybdenum, selenium, and cobalt.
    • Silicates of zinc, copper, iron, manganese, molybdenum, selenium, and cobalt.
  • NOTES:
    • Micronutrients— may only be used for fertility, and there must be a documented deficiency in the form of a soil or tissue test. 
    • Micronutrients made from nitrates or chlorides are prohibited.
    • If a grower does not have a documented deficiency, but still wants to add micronutrients to their soil, they can look into a CNG approved product, such as azomite.

Plant Pests and Diseases – Restricted Substances

General use of Plant Pest Products 

Approved plant pest products are allowed in conjunction with the use of preventive, mechanical, physical, and other pest management practices, so that spraying is not the first and only line of defense. Some examples of pest management practices include: crop rotation, cultivating beneficial insect habitat, releasing beneficial insects, trap cropping, pest monitoring, manual removal, and selecting pest resistant varieties.

General use of Plant Disease Products

Approved plant disease products are allowed in conjunction with the use of preventive, mechanical, physical, and other disease management practices, so that spraying is not the first and only line of defense. Some examples of disease management practices include: crop rotation, selecting disease resistant varieties, precision irrigation, pruning and trellising, manual removal, and crop diversification.

  • Boric acid—Must not come into direct contact with food or crops
  • Copper – must be used in a manner that prevents accumulation in the soil
  • Soaps ‐non‐detergent only (such as a castille or insecticidal soap); for food crops only; as a pesticide, fungicide, or algaecide.
    • NOTE: If used as herbicide, must be used only on non‐food plants or around buildings, roadways, etc. Cannot be used for disease control.

Weed Management and Miscellaneous – Restricted Substances

General use of Herbicide Products

Approved herbicide products are allowed in conjunction with the use of preventive, mechanical, physical, and other weed management practices, so that spraying is not the first and only line of defense. Some examples of weed management practices include: cultivation, hand pulling, mowing, timely weeding, mulching, tarp occultation, and flame weeding.

Herbicidal soaps – must not come into contact with crops, only for controlling weeds around buildings and roadways

Restricted Substances for Livestock

  • Atrophine – only by lawful written order of veterinarian and with a meat withdrawal period of 56 days for slaughter stock, and milk discard of 12 days for dairy.
  • BioWorma – may be used as part of a holistic parasite prevention and management plan, providing the producer can justify its use. 
  • Butrophanol – only by lawful written order of veterinarian and with a meat withdrawal period of 56 days for slaughter stock and milk discard of 12 days for dairy.
  • Dewormers – Moxidectin (Cydectin) and fenbenzadole (Safeguard) (for dairy stock and breeder stock) – only for emergency treatment, milk products from a treated animal may not be marketed as CNG for 90 days. For breeder stock, must not be used during the third trimester. These are prohibited for use on slaughter stock.
  • Poloxalene – only for emergency treatment of bloat.

Prohibited Substances for Produce

Fertility, Soil Amendments, and Potting Mixes – Prohibited Substances

  • Ash from manure burning
  • Chemically processed minerals, including quick lime and sugar lime
  • Compost with sewage sludge, or “biosolids”
  • Glossy paper or paper with colored ink
  • Rockwool
  • Synthetic compost starter
  • Synthetic fertilizers such as
    • Ammoniacal nitrogen
    • Potassium chloride
    • Synthetic nitrates
    • Synthetic phosphates
    • Urea and uric acid
  • Hydroponic nutrient solutions, even if OMRI-listed
  • Synthetic wetting agents

Plant Pests and Diseases – Prohibited Substances

  • Detergent-based soap products
  • Heavy metal or petroleum based pesticides
  • Nicotine sulfate and other tobacco products
  • Rotenone
  • Synthetic insecticides, fungicides, miticides such as
    • Allethrins
    • Metam Sodium
    • Neonicotinoids
    • Synthetic Pyrethoids
  • Synthetic wetting agents

Weed Management and Miscellaneous- Prohibited Substances

  • Heavy metal or petroleum based herbicides
  • Micronutrient-based herbicides
  • Paper mulch with glossy paper or paper with colored ink
  • Soap-based herbicides
  • Synthetic and DNA herbicides such as
    • 2,4-D
    • Atrazine
    • Dicamba
    • Glyphosate

Prohibited Substances for Livestock

Livestock External Parasiticides – Prohibited Substances

  • Parasiticides are prohibited 

Livestock Feed Additives – Prohibited Substances

  • Feed grown or treated with synthetic fertilizers or pesticides
  • Genetically modified feed or probiotics
  • Slaughter bi-products, urea and manure re-feeding

Livestock Health – Prohibited Substances

  • Antibiotics
  • Genetically modified probiotics
  • Ivermectin
  • Most conventional veterinary medications 

Additional useful resources

Published Oct 31, 2018