Skip to main content

Organic 101: Allowed and Prohibited Substances

Posted by Miles McEvoy, National Organic Program Director in Food and Nutrition Research and Science
Jul 28, 2022

The basic rule for organic agriculture is to allow natural substances and prohibit synthetic. For livestock like these healthy cows, however, vaccines play an important part in animal health—especially since antibiotic therapy is prohibited.
The basic rule for organic agriculture is to allow natural substances and prohibit synthetic. For livestock like these healthy cows, however, vaccines play an important part in animal health—especially since antibiotic therapy is prohibited. (Photo courtesy Pleasantview Farm, an Ohio certified organic dairy farm)

This is the second  installment of the Organic 101 series that explores different aspects of the USDA organic regulations.

Organic standards are designed to allow natural substances in organic farming while prohibiting synthetic substances. The National List of Allowed and Prohibited Substances—a component of the organic standards—lists the exceptions to this basic rule.

NOTE: Reshared from the archives, still true today.

The National Organic Standards Board (NOSB) is designed by law to advise the National Organic Program (NOP) on which substances should be allowed or prohibited.  Made up of dedicated public volunteers appointed by the Secretary of Agriculture, board members include organic growers, handlers, retailers, environmentalists, scientists, USDA-accredited certifying agents and consumer advocates.

NOSB members must use specific criteria when voting, including the need for the substance and its impacts on human health and the environment.  In specific cases, the NOSB also votes to allow non-organic versions of a substance if it isn’t available in organic form on a scale large enough to support organic agriculture.

Some synthetic substances are listed as exceptions to the basic rule and are allowed for use in organic agriculture.  For instance, pheromones have long been used as an effective, non-toxic way to “confuse” insects that may otherwise infest organic crops, especially fruit. Likewise, vaccines for animals are important disease prevention tools against many infectious diseases, especially since antibiotic therapy is prohibited in organic livestock.

The National List also allows certain processing aids, such as baking soda. This substance lightens (or leavens) the dough for organic pancakes, baked goods, and other products.

Conversely, some substances like strychnine and arsenic are examples of natural toxic substances that are prohibited in organic production.

The process for adding or removing allowed substances is an open process, allowing for direct input from the organic community.  The process typically follows these steps:

  1. An individual or organization submits a formal petition to add, remove, or change the listing for a specific substance.
  2. NOSB sub-committee reviews the petition. A third-party technical report is often used to gather scientific information about the substance and to identify any negative impacts to human health or the environment.
  3. The NOSB sub-committee publishes a proposed recommendation for the substance with request for public comments before a public meeting, typically held twice per year.
  4. During the meeting, the NOSB discusses the public comments related to the petition and then votes in a public forum. All NOSB meetings are free and open to the public.
  5. The NOP reviews the NOSB’s recommendation. The NOP can reject the NOSB’s recommendation to add a substance to the National List, but can’t add a substance that hasn’t been recommended by the NOSB.
  6. If the NOP agrees with the NOSB’s recommendation, it initiates rulemaking to amend the National List for that substance.

Through this process the NOSB devotes countless hours to discussing the range of perspectives on each substance under their review. The public comment process plays an important role in ensuring that all perspectives are considered thoroughly.

Since this citizen advisory board represents all key sectors of the organic community, the NOSB’s recommendations provides the NOP with invaluable insight into which substances should be allowed or prohibited in organic agriculture. The NOP invites the public to participate in this process as we shape the future of organic agriculture.

Write a Response

CAPTCHA This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.


Pete Mack
Mar 11, 2013

Hi there
I would like to know if Fluoride is an accepted substance under the organic certification umbrella?
Thank you.

Susan Snow
Jul 08, 2013

Fluoride is a synthetic poison and unless regulations have changed during this administration,it is not allowed under organic certification.

Jul 22, 2013

Does USDA Organic mean NON-GMO? Pls. confirm!
Thank you!

Jul 22, 2013

Is it posible to get agrant to do organic farmingand enough to get abuilding and some land?

Feb 21, 2014

Does USDA Organic mean it was grown in the USA or does "China Organic" (which is not really organic) also qualify under USDA?

Ben Kleschinsky
Apr 27, 2014

In your response to fluoride. The synthetic form of fluoride is not allowed but fluoride is naturally found in soil some places higher amounts than others. For instance USDA Organic Tea contains a decent amount of flouride in it because the tea plant attracts fluoride and sucks it up and its dispersed throughout the plant. That is why White Tea has become more popular. It's picked at a younger age so it doesn't have as much time to accumulate as much fluoride.

It goes by this, white tea youngest green tea middle aged, black tea is oldest and therefore contains the most fluoride. There are many different other types of tea some picked younger some picked older

Don't know if any other plant attracts fluoride but I'm sure. Of coarse buying tea that specifically says not from concentrate on the bottle or actually buying the real thing leave will reduce the amount of fluoride. One because then you can make it at home and you can be sured its brewed not with fluoride tap water but spring water. The other reason is if its from concentration they use a lot more liquid to make it and it probably made with fluoridated tap water.

Not to alarm anyone but the amount of fluoride that white tea picks up is perfectly safe for you body and actually makes your teeth strong. Not the same artificial fluoride found in toothpaste. Trace amounts of fluoride are also found in all fruits and vegetables from the soil. So is trace amounts of Mercury and Lead. Fluoride is not dangerous, the synthetic form is. Hope that answered your questions. Nothing to worry about at all but I do drink White Tea now just to be safe.

Jun 19, 2014

Where is a link to the National List?

Regenia Rothlauf
Jun 10, 2015

is the use of chlorinated water permitted in organic cookie baking?

Ben Weaver
Jun 10, 2015

@Regenia Rothlauf - that's a great question. For organic food handling facilities and equipment, chlorine materials may be used for disinfecting and sanitizing food contact surfaces. Water used as an ingredient in organic food handling should not exceed the maximum residual disinfectant limit for the chlorine material under the Safe Drinking Water Act. The maximum residual disinfectant level is a term defined by the Environmental Protection Agency (EPA) as the highest level of a disinfectant allowed in drinking water. This level is currently established by EPA at 4 mg/L for chlorine (as Cl2) and 0.8 mg/L for chlorine dioxide.

Aug 29, 2015

is chicken feather meal allowed as an organic input for crop production?

Julie Swensgard
Oct 21, 2015

The question about whether organic allows GMO products was not answered. I would like that answered.

Dec 08, 2015

How often do you actually visit this page to answer questions? Once every 3 or 4 months? That is not very useful. Are you hoping that people will forget that they asked something important to them? A better effort here would be appreciated.

robert l. zimdahl
Jan 24, 2016

My search has not revealed if pelargonic acid (scythe) is approved for use as a herbicide in organic agriculture. Is it?

Erick Trujillo
Mar 08, 2016

Hello there is the iron Stock is allowed in NOP?

Marlene Placido
Mar 26, 2016

My question is about second generation herbicides, as in compost made from glysophate laden spent grains from the brewing of beer? Can crops grown in this compost be organically certified ?

Richard Dyer
May 11, 2016

Since no0ne else is addressing the Non-GMO question, I'll give it a shot.
Any crop that is Certified Organic is by definition Non-GMO. But all NON-GMO labeled products are not organic. Non-GMO have not used GMO seed but could have used all kinds of synthetic chemicals as pesticides, fertilizers and possibly herbicides. It just means the plant has not been manipulated in the lab to have modified DNA.

pablo intriago
Jun 15, 2016

good day

I would like to know if there is any regulation in the use of essential oils, and or herbal or botanical extracts??.



Aug 05, 2016

Thank you for the laughs. "Synthetic fluoride" is now on my list of favourite phrases. All fluorine/fluoride is about as raw/organic/natural as possible, seeing as how it's an element.

Morten B Larsen
Aug 14, 2016

When using hypochlorous acid as a disinfectant (natural part of our immune system) is that considered approved for organic farming and for preparing produce, meats and poultry?

We produce HOCL(Hypochlorous acid) using 99.9% Natural salt (NaCl with no additives), water and electricity, all natural ingredients!

Sep 15, 2016

I would like to know if "Tiovit jet" by Syngenta is an accepted substance under NOP USDA certification?
Thank you.

Oct 17, 2016


Does USDA allow non-toxic pesticides on fruit and vegetables? If so, which chemicals are used and how much is used in grams per fruit?


Ben Weaver
Oct 18, 2016

@Mar - thanks for the comment. In general, synthetic substances are prohibited for organic production unless specifically allowed and non-synthetic substances are allowed for organic production unless specifically prohibited. The National List of Allowed and Prohibited Substances identifies both synthetic substances that may be used and the nonsynthetic substances that may not be used in organic production. It also identifies non-organic substances that may be used in or on processed organic products. Some substances on the National List may only be used in specific situations (only for certain crops or up to a maximum amount). You can <a href="…; rel="nofollow">view the National List online</a>.

Oct 19, 2016

I would like to known if acidulant citric acid is allowed as processing aid under NPOP and USDA NOP standard.
Thank you,

Ben Weaver
Oct 24, 2016

@Patil - thanks for the comment. Citric acid is allowed if it is produced by microbial fermentation of carbohydrate substances (<a href="…; rel="nofollow">7 CFR 205.605(a)</a>). Any substance used in the production or handling of organic products must be reviewed and approved by your certifying agent.

Dec 01, 2016

Where can i find how many ppm of arsenic are allowed on an OIM

William Heritage
Dec 06, 2016

We are producing Fulvates and Biochar for agricultural use. Can organic farmers use our product if it is made from barn silage containing urine and manure. The temperature reached is over 350°F

Mike Baker
Apr 20, 2017

I use coca cola on my garden; less than 5% for the phosphorus content. Am I an inorganic gardener?

Alan Glasser
May 15, 2017

Can anyone please tell me what is in the 5% of approved food additives allowed for "organic foods" ? I'm writing a short column for our 55 and older community newsletter and I can't seem to find this information anywhere. Thanks.

Ben Weaver
May 16, 2017

@Alan Glasser - Product labeled as “organic” must contain a minimum of 95% organic ingredients. The other 5% may include a limited number of non-organic materials that are essential to organic processing and not available in an organic form. These non-organic materials are listed on the National List (…). Examples include sodium bicarbonate (baking soda), citric acid, and fish oil.

For more information, you may wish to review the following fact sheet: Allowed and Prohibited Substances in Organic Production and Handling ( Substances.pdf)

Jun 13, 2017

Is there a list of "active substances "that are allowed or prohibited in organic farming,other than the Natioanl List of Allowed and prohibited Substances. ?

Ben Weaver
Jun 16, 2017

@joash - No, only the National List of Allowed and Prohibited Substances identifies the synthetic substances that may be used and the nonsynthetic (natural) substances that may not be used in organic crop and livestock production. It also identifies a limited number of non-organic substances that may be used in or on processed organic products.

Here's the link:

Jul 09, 2017

Are concrete blocks containing Fly Ash prohibited for use in raised beds under Organic Guidelines? I've real through some things but haven't seen anything specifically referencing Fly Ash.

Dr. Rene Soto
Jul 14, 2017

Do you have a list of companies that produce organic product?

Ben Weaver
Jul 18, 2017

@Dr. Rene Soto - thank you for your comment. The National Organic Program’s Integrity Database lists USDA organic certified operations, including farms and other businesses.

Artelias Aikens
Sep 01, 2017

I like this article!

hue fussell
Sep 06, 2017

i need a list of all organic products that can be used in and organic insect repellent

hue fussell
Sep 06, 2017

i would like to know if
sodium lauryl sulfate
polyceryl oleate
sodium choride
ethyl lactate
sodium citrate
vitamin e
could be used in an organic product??

Diane Noonan
Oct 03, 2017

Has there ever been a need for waiting 72 hours after an organic production run of applying a pesticide for ants or other pests in a facility where one works with organic and non organic products

Oct 05, 2017

I was wondering if we are allowed to use organic acids such as formic and lactic acid in broiler diets.

Looking forward to hearing from you,



Jan 19, 2018

I'm extremely confused by the NOP's article on Cosmetics, Body Care products and personal care products. It states that It can be certified by the NOP but in the last two paragraphs it all states that USDA/NOP has no authority to regulate it.

Zack Lantz
Apr 08, 2018

Hi, I am curious as to if we can have Butane or Propane certified organic for our clients who require such certifications? The only other option is to use a poor choice solvent such as ethanol for our processes should we not be capable of using butane or propane under the umbrella.1

Ben Weaver
May 04, 2018
@Zack Lantz - Volatile solvents are not allowed in organic processing.
Apr 13, 2018

Hi, i cant help but respond to someones post saying that all forms of flouride are natural and not synthetic. No, not all forms are natural. The flouride that is put in the publics drinking water is a by product of the aluminum industry and actually has a different name, but i cant remember what that is right now.

Indrani kanungo
Apr 18, 2018

I want to know that is Sodium and calcium hypochlorite are chlorinated inorganic disinfectants banned by USDA?

Ben Weaver
May 04, 2018

@Indrani kanungo - Sodium hypochlorite and calcium hypochlorite are included on the National List of Allowed and Prohibited Substances. They are allowed for use in organic crop and livestock production. For more information, please see Sections 205.601 and 205.603 of the organic regulations.

Lovely Cabulanan
Apr 18, 2018

Is it allowed to use a non-organic honey for Banana Chips honey dipped?

Ben Weaver
May 04, 2018

@Lovely Cabulanan - Non-organic honey is not currently included on the National List of Allowed Substances and would not be allowed in organic production.

Berenice Muñoz
Apr 26, 2018


I want to know if the citric acid (that is a allowed additive) has a limit of use in a food organic

Thank you

Ben Weaver
May 04, 2018

@Berenice Muñoz - The National List allows citric acid, a nonagricultural, nonorganic substance, to be used as an ingredient in or on processed products labeled as “organic” or “made with organic.” For information on the limits of use, view the “Organic” and “Made with Organic” sections of the fact sheet on Allowed and Prohibited Substances.