National Organic Program | Agricultural Marketing Service | U.S. Department of Agriculture

Formal Recommendation 

From: The National Organic Standards Board (NOSB)

To: The National Organic Program (NOP)

Date: October 26, 2023

Subject: 2025 Crops Sunset Reviews

NOSB Chair: Nate Powell-Palm

The NOSB hereby recommends to the NOP the following: 

Rulemaking Action: X

Statement of the Recommendation: 

The NOSB recommends the following sunset substances be renewed:

§205.601 Sunsets: Synthetic substances allowed for use in organic crop production: 

• Alcohols: Ethanol

• Alcohols: Isopropanol

• Sodium carbonate peroxyhydrate

• Newspaper or other recycled paper, without glossy or colored inks (§205.601(b) - mulch)

• Newspaper or other recycled paper, without glossy or colored inks (§205.601(c) - compost 

feedstock)

• Plastic mulch and covers

• Aqueous potassium silicate (§205.601(e) - insecticide)

• Aqueous potassium silicate (§205.601(i) - plant disease control)

• Elemental sulfur (§205.601(e) - insecticide; §205.601(i) - plant disease control; §205.601(j) - 

plant or soil amendment

• Lime sulfur (§205.601(e) - insecticide)

• Lime sulfur (§205.601(i) - plant disease control)

• Hydrated lime

• Liquid fish products

• Sulfurous acid

• Ethylene gas

• Microcrystalline cheesewax

§205.602 Sunsets: Nonsynthetic substances prohibited for use in organic crop production:

• Potassium chloride

NOSB Votes: Please see individual substances below for justifications, votes, and outcomes
Alcohols: Ethanol

Reference: 205.601(a) As algicide, disinfectants, and sanitizer, including irrigation system cleaning 

systems. 

(1) Alcohols. (i) Ethanol.

Technical Report(s): 1995 TAP; 2014 TR

Petition(s): N/A

Past NOSB Actions: 11/1995 NOSB minutes and vote (pg. 17-18); 11/2005 NOSB sunset 

recommendation; 04/2011 NOSB sunset recommendation; 10/2015 NOSB sunset recommendation; 

10/2018 NOSB sunset recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Sunset renewal 

notice published 10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); 

Sunset renewal notice published 03/15/2017 (82 FR 14420); Sunset renewal notice published 

05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

Ethanol is used in organic crop production as an algicide, disinfectant, and sanitizer, including irrigation 

system cleaning.

Manufacture:

Ethanol can be produced by fermentation and chemical synthesis through direct or indirect hydration of 

ethylene. Fermentation to produce ethanol can use starch, sugar, or cellulose using either natural or 

genetically engineered strains of bacteria or yeast.

International Acceptance:

Canadian General Standards Board Permitted Substances List

Ethanol is listed as a synthetic for organic crop and livestock production.

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Ethanol is listed as a synthetic for organic crop and livestock production.

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

Ethanol is listed as a synthetic for organic crop and livestock production.

International Federation of Organic Agriculture Movements (IFOAM)

Ethanol is listed as a synthetic for organic crop and livestock production.

Japan Agricultural Standard (JAS) for Organic Production

Ethanol is listed as a synthetic for organic crop and livestock production.

Environmental Issues:

According to the United States Environmental Protection Agency (EPA), the agency that regulates all 

non-food applications of ethanol, ethanol is practically non-toxic based on acute oral and inhalation 
toxicity tests. Ethanol is biodegradable in air, soil, and water. Ethanol can contribute to smog but would 

be minimal in the quantities used.

Discussion:

During the Spring 2023 NOSB meeting, the Board reviewed both ethanol and isopropanol, noting that 

there is little to no environmental or human health impacts associated with the use of ethanol. 

Members were supportive of relisting. The NOSB also reviewed public comments. Farmers indicated 

that ethanol and isopropanol could be used for cleaning tools and pruning shears, cleaning drip lines 

that become clogged, and during post-harvest handling to sanitize and disinfect equipment. Ethanol 

and Isopropanol are readily available in rural areas. 

One question was posed to the community about requiring organically-produced ethanol if sufficient 

quantities are available for organic production and there was agreement that this conversation points to 

a larger discussion about whether all crop inputs, including manures, should be sourced organically. 

During the Fall 2023 meeting, NOSB members agreed that this material was necessary, useful, and 

should remain on the list.

Justification for Vote: 

The NOSB finds alcohols: ethanol compliant with the Organic Foods Production Act (OFPA) and/or 7 CFR 

205.600 and is not proposing removal.

NOSB Vote: 

Motion to remove alcohols: ethanol from the National List

Motion by: Logan Petrey 

Seconded by: Brian Caldwell

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed

Alcohols: Isopropanol

Reference: 205.601(a) As algicide, disinfectants, and sanitizer, including irrigation system cleaning 

systems. 

(1) Alcohols. (ii) Isopropanol.

Technical Report(s): 1995 TAP; 2014 TR

Petition(s): N/A

Past NOSB Actions: 11/1995 NOSB minutes and vote (pg. 17-18); 11/2005 NOSB sunset 

recommendation; 04/2011 NOSB sunset recommendation; 10/2015 NOSB sunset recommendation; 

10/2018 NOSB sunset recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Sunset renewal 

notice published 10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); 

Sunset renewal notice published 03/15/2017 (82 FR 14420); Sunset renewal notice published 05/07/20 

(85 FR 27105)

Sunset Date: 6/22/2025
NOSB Review:

Use:

Isopropanol is used for a variety of industrial and consumer uses. In organic crop production, 

isopropanol can be used as an algicide, disinfectant, and sanitizer, including irrigation system cleaning. 

Isopropanol has broad-spectrum antimicrobial activity against vegetative bacteria, viruses, and fungi.

Manufacture:

Isopropanol is a synthetic compound that is manufactured by hydration of petroleum-derived 

propylene. Acetone can also be used as a hydrated base chemical over a metal catalyst.

International Acceptance:

Canadian General Standards Board Permitted Substances List 

Canadian organic production standards permit the use of isopropanol for a number of agricultural 

applications.

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Alcohols, presumably including isopropanol, may be used for cleaning and disinfecting livestock building 

installations and utensils.

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

“Need recognized by certification body or authority”

International Federation of Organic Agriculture Movements (IFOAM)

No information found 

Japan Agricultural Standard (JAS) for Organic Production

No information found

Environmental Issues:

The United States Environmental Protection Agency (EPA) considers isopropanol slightly toxic to 

practically non-toxic on acute oral and inhalation toxicity tests. The alcohol can contribute to smog and 

ozone formation, but large-scale releases are unlikely based on prescribed use in organic agriculture.

Discussion:

The NOSB reviewed the use, manufacturing, and environmental concerns of isopropanol, and previous 

NOSB reviews, and supports relisting. The NOSB discussed comments from the Spring 2023 meeting. 

Farmers indicated that ethanol and isopropanol could be used for cleaning tools and pruning shears, 

cleaning drip lines that become clogged, and during post-harvest handling to sanitize and disinfect 

equipment. Ethanol and isopropanol are readily available in rural areas. 

During the Fall 2023 meeting, NOSB members agreed that this material was necessary, useful, and 

should remain on the list.

Justification for Vote: 

The NOSB finds alcohols: isopropanol compliant with the Organic Foods Production Act (OFPA) and/or 7 

CFR 205.600 and is not proposing removal.
NOSB Vote: 

Motion to remove alcohols: isopropanol from the National List

Motion by: Logan Petrey

Seconded by: Amy Bruch

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed

Sodium carbonate peroxyhydrate

Reference: 205.601(a) As algaecide, disinfectants, and sanitizer, including irrigation system cleaning 

systems. 

(8) Sodium carbonate peroxyhydrate (CAS #-15630-89-4)—Federal law restricts the use of this substance 

in food crop production to approved food uses identified on the product label.

Technical Report: 2006 TR; 2014 TR

Petition(s): 2005

Past NOSB Actions: 11/2007 NOSB recommendation; 10/2014 NOSB sunset recommendation; 10/2018 

NOSB sunset recommendation

Regulatory Background: Added to National List 12/13/2010 (75 FR 77521); Sunset renewal notice 

published 06/19/2015 (80 FR 35177); Sunset renewal notice published 05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

According to the 2014 TR and previous reviews by the Board, sodium carbonate peroxyhydrate (SCP) has 

been used in organic production as an algaecide in rice fields, ponds, ditches, and irrigation lines. It was 

added to the National List in 2007 as an alternative to materials such as copper and chlorine; it has been 

registered for use in rice since 2010. In wider legal uses of the substance, “In its primary registration by 

the US Environmental Protection Agency (EPA) as a biopesticide, use sites for sodium carbonate 

peroxyhydrate include ornamental plants, turf grasses, terrestrial landscapes, commercial greenhouses, 

garden centers, nurseries and storage areas. Target pests included algae, moss, liverworts, slime molds 

and their spores. There was no food use authorized. (TR 104-107)

Manufacture:

According to the 2014 TR, “Sodium carbonate peroxyhydrate is the chemical name for an addition 

product produced by drying hydrogen peroxide in the presence of sodium carbonate (CAS No. 497-19-

8). The pure substance contains 32.5 % hydrogen peroxide and 67.5 % sodium carbonate (based on 

weight)” (TR 51-53). 

The TR lists three common manufacturing processes via drying, crystallization and a spray granulation 

process. “The dry process involves spraying an aqueous stabilized hydrogen peroxide solution on solid 

sodium carbonate with continuous agitation. A solid-liquid reaction yields sodium carbonate 

peroxyhydrate” (TR 232-33). “In the spray granulation process, solutions of sodium carbonate and 

aqueous stabilized hydrogen peroxide are sprayed onto a bed of sodium carbonate peroxyhydrate nuclei 
in a fluid-bed granulator. The product bed is kept in movement by a stream of heated air. Product is 

continuously withdrawn from the dryer and the desired grain-size fraction is obtained by classification” 

(TR 235-238). “The crystallization process takes advantage of the high solubility of sodium carbonate 

peroxyhydrate. In this method, sodium carbonate peroxyhydrate is salted out of aqueous solutions with 

sodium chloride. A sodium carbonate/NaCl suspension is reacted with stabilized hydrogen peroxide 

under stirring and cooling. The crystallized sodium carbonate peroxyhydrate is separated from the 

mother liquor by centrifugation, and drying in a fluid-bed dryer” (TR 240-244).

International Acceptance:

Canadian General Standards Board Permitted Substances List

(As of 2014 TR) “Hydrogen peroxide is on the Canadian Organic Production Systems Permitted 

Substances Lists (CAN/CGSB-32.311-2006). It is listed for use as a fungicide. Sodium carbonate (soda 

ash) is considered a natural substance in the Canadian system. Sodium carbonate peroxyhydrate is not 

included in any of the Canadian permitted substance lists” (TR 168-171).

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008 (As of 2014 

TR) “Sodium carbonate peroxyhydrate is not listed as a permitted substance for organic production”(TR 

187)

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (CXG 32-1999)

(As of 2014 TR) “Although Codex Alimentarius permits the use of sodium carbonate peroxyhydrate as an 

anti-bactericide in raw milk, it is not included in any list for organic use” (TR 176-77).

International Federation of Organic Agriculture Movements (IFOAM) Norms

(As of 2014 TR) “Sodium carbonate peroxyhydrate is not listed or discussed for use in the IFOAM norms” 

(TR 201).

Japan Agricultural Standard (JAS) for Organic Production 

(As of 2014 TR) “Sodium carbonate peroxyhydrate, hydrogen peroxide and sodium carbonate are not 

specifically listed in the Japanese Agricultural Standard for Organic Plants” (TR 195-196).

Environmental Issues:

An emission of sodium carbonate peroxyhydrate to the environment could occur during production, 

formulation, and use of the substance (TR lines 323-24). Sodium, carbonate, and hydrogen peroxide do 

not adsorb to sediment (TR line 333). No new concerns were raised about human health or 

environmental effects since the earlier review in 2006; however, the substance can have negative 

impacts on fish, birds and bees. “Aquatically, toxic effects of sodium carbonate peroxyhydrate on fish 

have been reported, but the sensitivity of different fish species depends on final hydrogen peroxide 

concentration, water temperature, and life stage” (TR 395-397). “Undissolved sodium carbonate 

peroxyhydrate is toxic to birds when ingested. However, once applied and dissolve in water sodium 

carbonate peroxyhydrate is not expected to be toxic to birds. Sodium carbonate peroxyhydrate is also 

highly toxic to bees and it should not be allowed to drift to flowering plants or used when contact with 

bees might occur” (TR 404-407).

Discussion:

The Crops Subcommittee took note of previous reviews of this substance. In the last review, the 

Subcommittee sought input comparing this material with copper sulfate for control of algal scum in rice 
production and asked if it could replace copper sulfate for that use. Limited and conflicting comments 

were received. Points raised in favor of renewing the substance stated that it provides better control of 

algae, and its breakdown components of water and oxygen are more favorable than the accumulation of 

elemental copper associated with copper sulfate. Additionally, when utilized in irrigation ponds sodium 

carbonate peroxyhydrate has fewer corrosion issues with irrigation equipment than copper sulfate. 

The Subcommittee expressed value in the continued presence of the substance on the National List, 

even if it is not a commonly used material. Additionally, the potential for inadvertent use as a fungicide 

in branded products marketed for both uses was discussed by the Subcommittee.

Public comments from the Spring meeting were supportive of relisting with a couple of notable details. 

A couple of stakeholders reminded the community that SCP was originally considered for use as a 

replacement for copper sulfate in rice production, does not fall under an OPFA category for crops use 

and the NOSB should consider whether the intended use is happening in practice and whether the 

listing should be more narrowly annotated. Consulting the transcripts for previous decision making, the 

NOSB recommendation at the time reflects that the Crops Subcommittee was originally unconvinced of 

the need and compatibility of the substance but that “(R)esulting public comment at the full NOSB 

meeting presented additional information that convinced most board members that the material’s 

environmental impacts were minimal and much more environmentally friendly than the copper sulfate 

now used as the principal farm pond and rice production algaecide”.

A farmer group described SCP as functioning better than copper sulfate for algae control; specifically 

noting that copper sulfate only reduces bloom whereas SCP prevents the growth of algae. Another 

farmer noted that the loss of this material could negatively impact farm economies and organic 

agricultural production. Certifiers listed low levels of use in OSPs in most regions of the country, except 

in rice growing regions, where a certifier listed 127 users, specifically reflecting support for SCP as an 

alternative to copper use.

Other public comments support this listing as a variety of options are needed for each application in 

order to prevent the buildup of microbial resistance; noted that this material breaks down into 

hydrogen peroxide and sodium carbonate, which further qualifies SCP as a material compatible with 

National List evaluation and criteria. Another commenter noted that their organization has observed 

efficacy and utility of the substance in practice.

The Subcommittee had a question about the EPA designation of SCP as a biopesticide and may seek 

information from EPA on its definitions. This is not an NOSB/OFPA concern, but the Subcommittee is 

interested in receiving clarity from the EPA.

Justification for Vote:

The NOSB finds sodium carbonate peroxyhydrate (SCP) compliant with the Organic Foods Production 

Act (OFPA) and/or 7 CFR 205.600 and is not proposing removal.

NOSB Vote:

Motion to remove sodium carbonate peroxyhydrate from the National List at 205.601(a)(8)

Motion by: Mindee Jeffery

Seconded by: Brian Caldwell

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed
Newspaper or other recycled paper, without glossy or colored inks

Reference: 205.601(b) As herbicides, weed barriers, as applicable. 

(2) Mulches. (i) Newspaper or other recycled paper, without glossy or colored inks.

Technical Report: 1995 TAP; 2006 TR; 2017 TR

Petition(s): N/A

Past NOSB Actions: 11/1995 NOSB minutes and vote (pg. 19); 11/2005 NOSB sunset recommendation; 

04/2011 NOSB sunset recommendation; 10/2015 NOSB sunset recommendation; 10/2018 NOSB sunset 

recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Sunset renewal 

notice published 10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); 

Sunset renewal notice published 03/15/2017 (82 FR 14420); Sunset renewal notice published 05/07/20 

(85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

Newspaper and other recycled paper is commonly used in organic agriculture as a non-chemical means 

of weed management and soil moisture retention, soil temperature moderation, and boosts to soil 

organic matter. It is also used to shade out plant growth; it then degrades into the soil.

Manufacture:

A 2017 Technical Report (TR, line 82) on this material reports that one-third to one-half of all paper in 

the United States is recycled into other paper products, and reports EPA figures from 2013 data that 

paper is recycled at a rate of 63% in the United States (line 87).

Recycled paper comes from a number of different sources that affect the grade of the recycled paper 

product; old corrugated containers, mixed paper, old newspapers, high grade de-inked paper, and pulp 

substitutes. These larger categories are further segmented into as many as 50 different sub-grades of 

recycled paper. Paper recovered for recycling is ultimately shredded and pulped to produce new paper 

products.

Some recycled paper cannot be made into other paper products but can become a feedstock for 

compost products, while some recycled paper carries too many contaminants – some of it toxic --

including plastics, motor oil, paint, glass, and other non-paper materials.

An important consideration of newspaper and recycled paper in organic production relates to the inks 

that are printed onto the paper. Black ink has historically been derived from vegetable- or petroleumbased sources that involve the use of solvents that can damage the environment in a variety of ways. 

Increasingly, black inks have become water-based, though not 100% solvent-free. The use of various 

heavy metal compounds in colored ink has been an important consideration in excluding colored inks 

from use in organic production. Similarly, while glossy inks can gain their functional components from 

nonsynthetics like bentonite or kaolinite, those functions can also come from petrochemical synthetic 

polymers like acrylonitrile, polyethylene (LDPE), styrene, butadiene, vinyl acetate, and polyvinyl chloride, 

excluding them from any use in organic production.
Adhesives, glues, waxes, and resins are also among the materials that could be found in newspaper and 

recycled paper products and raise similar questions to those posed during prior reviews of the separate 

National List substance, biodegradable biobased mulch film.

Paper mulches are not regulated as an herbicide by the EPA and are considered inert.

It is worth noting that virgin, or non-recycled paper, comes from a variety of plant materials, including 

wood, trees, straw, hemp, sugarcane bagasse, bamboo, reeds, and kenaf, with the majority coming from 

wood fibers. As noted in the 2017 TR (line 68), most of the wood fibers derived from trees used for 

paper production do not incorporate methods considered to be excluded from organic production. 

However, some genetically modified trees are being produced that could potentially be used in paper 

production in the future. Some sources have reported that as many as 200 different chemicals can be 

used to make it possible to use tree fiber as a feedstock for paper production (Discover Magazine, April 

4, 2014).

International Acceptance:

Canadian General Standards Board Permitted Substances List

Permitted for use but only “without glossy paper and coloured ink.”

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Not specified as permitted for use.

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (CXG 32-1999)

Not specified as permitted for use.

International Federation of Organic Agriculture Movements (IFOAM) Norms

Not specified as permitted for use.

Japan Agricultural Standard (JAS) for Organic Production

Not specified as permitted for use.

Environmental Issues:

While recycled paper production is assumed to have fewer environmental impacts than virgin paper 

production, it still presents issues. Sodium hydroxide and other chemical additives and surfactants may 

be introduced into the process. The de-inking sludge – or wastewater byproduct – that is produced from 

paper recycling can contain a number of synthetic materials and is typically landfilled, burned, or cocomposted with sewage and poultry litter.

That said, the use of recycled paper ensures that trees are not harvested for the production of paper, a 

process that has much more far-reaching impacts including the loss of habitat, disturbance or 

destruction of soils, and the destabilization of carbon sinks.

Discussion:

At the 2015 NOSB sunset review, it came to the attention of both the NOSB and the public that there are 

new, less toxic materials used in production of newspaper and other recycled paper products which 

could stimulate the NOSB to consider a change to the annotation for this material. A technical report 
(TR) was requested and subsequently completed in summer 2017. The TR revisited the ingredients and 

colored inks in newspaper as well as their effect on the environment.

While there has been progress towards less toxic materials used in inks, and more recycling of paper 

products since the original listings and annotation of newspaper and recycled paper, it is difficult-toimpossible to determine if the inks present in the newspaper are ones that are less problematic. There is 

no methodology to distinguish between color inks that might be more acceptable for direct application 

to organic land and those that are not. When reviewing the 2017 TR, the Crops Subcommittee decided 

the current annotation for newspaper and recycled paper, which prohibits glossy or colored inks, should 

remain. This conclusion was presented as an update to the full NOSB at the Fall 2017 NOSB meeting. The 

NOSB unanimously voted to continue this listing at § 205.601(b) in 2018.

There was continued support for this material to remain on the National List with the current 

annotation. Certifiers, grower groups, and individual growers all submitted comments in favor of 

retaining this material in both locations on the National List (§§ 205.601(b) and 205.601(c)). While some 

stated there was currently not much use of this material in organic crop production, they also stated it 

should continue to be allowed for those who wish to continue using it. One certifier noted that 

newspaper could be included in manure that is cleaned out of livestock barns, supporting the relisting as 

a compost feedstock.

At the Spring 2023 NOSB meeting, the full Board discussed this material at some length. Discussion 

focused on whether it is reasonable to assume that all/most newspaper and other recycled paper would 

be produced with the inks required by the annotation and, if not, how that would create issues for 

certifiers. This discussion continued in subcommittee after the Spring 2023 meeting, noting that the 

assumption that all recycled paper is using less-problematic inks may not be correct. The Board 

considered whether the listing also included cardboard and confirmed its understanding that it did. The 

Board also discussed the separate Spring 2021 vote to approve paper pots and paper-based planting 

aids and the findings during that process that some of the materials of potential concern found in paper 

pots are also the components of newspaper and other recycled paper.

Questions to our Stakeholders:

1. Should there be an annotation for this listing that attempts to further clarify what uses are 

acceptable within organic production? Can certifiers appropriately oversee the ink requirement in 

this annotation?

2. How widely used are these materials in organic production?

3. What is the scale of use of this material for this purpose in organic production (specifically number 

of users, farms, acres, geographical reach)?

Public comments on this material have been clear: this is an important material for many growers, 

particularly small producers, but there is concern that materials of concern (for example, PFAS) may be 

present in newspaper and other recycled paper and that certifiers have difficulty inspecting this material 

despite seeing it on many OSPs. Several commenters have called for caution in using this material, or to 

elevate it on the NOSB’s work agenda (it will be part of the NOSB’s compost work agenda item for 2024, 

which could have implications for this listing as well). Discussion at the Fall 2023 NOSB meeting reflected 

these challenges noted by the stakeholder community, but support for relisting was clear.
Justification for Vote:

The NOSB finds newspaper or other recycled paper, without glossy or colored inks compliant with the 

Organic Foods Production Act (OFPA) and/or 7 CFR205.601(b) and is not proposing removal.

NOSB Vote::

Motion to remove newspaper or other recycled paper, without glossy or colored inks from the National 

List at 7 CFR 205.601(b)

Motion by: Wood Turner

Seconded by: Mindee Jeffery

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed

Newspaper or other recycled paper, without glossy or colored inks

Reference: 205.601(c) As compost feedstocks—Newspapers or other recycled paper, without glossy or 

colored inks.

Technical Report: 1995 TAP; 2006 TR; 2017 TR

Petition(s): N/A

Past NOSB Actions: 11/1995 NOSB minutes and vote (pg. 19); 11/2005 NOSB sunset recommendation; 

04/2011 NOSB sunset recommendation; 10/2015 NOSB sunset recommendation; 10/2018 NOSB sunset 

recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Sunset renewal 

notice published 10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); 

Sunset renewal notice published 03/15/2017 (82 FR 14420); Sunset renewal notice published 

05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

Newspaper and other recycled paper is commonly used in organic agriculture as a compost feedstock. 

Effectively, the newspaper or recycled paper is a carbon source – or food -- for active compost 

processing.

Manufacture:

A 2017 Technical Report (TR, line 82) on this material reports that one-third to one-half of all paper in 

the United States is recycled into other paper products, and reports EPA figures from 2013 data that 

paper is recycled at a rate of 63% in the United States (line 87).

Recycled paper comes from a number of different sources that affect the grade of the recycled paper 

product: old corrugated containers, mixed paper, old newspapers, high grade de-inked paper, and pulp 

substitutes. These larger categories are further segmented into as many as 50 different sub-grades of 

recycled paper.
Some recycled paper cannot be made into other paper products but can become a feedstock for 

compost products, while some recycled paper carries too many contaminants – some of it toxic --

including plastics, motor oil, paint, glass, and other non-paper materials.

An important consideration of newspaper and recycled paper in organic production relates to the inks 

that are printed onto the paper. Black ink has historically been derived from vegetable- or petroleumbased sources that involve the use of solvents that can damage the environment in a variety of ways. 

Increasingly, black inks have become water-based, though not 100% solvent-free. The use of various 

heavy metal compounds in colored ink has been an important consideration in excluding colored inks 

from use in organic production. Similarly, while glossy inks can gain their functional components from 

nonsynthetics like bentonite or kaolinite, those functions can also come from petrochemical synthetic 

polymers like acrylonitrile, polyethylene (LDPE), styrene, butadiene, vinyl acetate, and polyvinyl chloride, 

excluding them from any use in organic production.

Adhesives, glues, waxes, and resins are also among the materials that could be found in newspaper and 

recycled paper products and raise similar questions to those posed during prior reviews of the separate 

National List substance, biodegradable biobased mulch film.

Composting is not federally regulated; therefore, neither is the use of paper as a compost feedstock. 

However, components of paper feedstock, such as heavy metals, could be regulated at the state level.

It is worth noting that virgin, or non-recycled paper, comes from a variety of plant materials, including 

wood, trees, straw, hemp, sugarcane bagasse, bamboo, reeds, and kenaf, with the majority coming from 

wood fibers. As noted in a 2017 TR (line 68), most of the wood fibers derived from trees used for paper 

production do not incorporate methods considered to be excluded from organic production. However, 

some genetically modified trees are being produced that could potentially be used in paper production 

in the future. Some sources have reported that as many as 200 different chemicals can be used to make 

it possible to use tree fiber as a feedstock for paper production (Discover Magazine, April 4, 2014).

International Acceptance:

Canadian General Standards Board Permitted Substances List

Permitted for use but only “without glossy paper and coloured ink.”

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Not specified as permitted for use.

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (CXG 32-1999)

Not specified as permitted for use.

International Federation of Organic Agriculture Movements (IFOAM) Norms

Not specified as permitted for use.

Japan Agricultural Standard (JAS) for Organic Production

Not specified as permitted for use.
Environmental Issues:

While recycled paper production is assumed to have fewer environmental impacts than virgin paper 

production, it still presents issues. Sodium hydroxide and other chemical additives and surfactants may 

be introduced into the process. The de-inking sludge – or wastewater byproduct – that is produced from 

paper recycling can contain a number of synthetic materials and is typically landfilled, burned, or cocomposted with sewage and poultry litter.

That said, the use of recycled paper ensures that trees are not harvested for the production of paper, a 

process that has much more far-reaching impacts including the loss of habitat, disturbance or 

destruction of soils, and the destabilization of carbon sinks.

Discussion:

At the 2015 NOSB sunset review, it came to the attention of both the NOSB and the public that there are 

new, less toxic materials used in production of newspaper and other recycled paper products which 

could stimulate the NOSB to consider a change to the annotation for this material. A technical report 

(TR) was requested and subsequently completed in summer 2017. The TR revisited the ingredients and 

colored inks in newspaper as well as their effect on the environment.

While there has been progress towards less toxic materials used in inks, and more recycling of paper 

products since the original listings and annotation of newspaper and recycled paper, it is difficult to 

impossible to determine if the inks present in the newspaper are ones that are less problematic. There is 

no methodology to distinguish between color inks that might be more acceptable for direct application 

to organic land and those that are not. When reviewing the 2017 TR, the Crops Subcommittee decided 

the current annotation for newspaper and recycled paper, which prohibits glossy or colored inks, should 

remain. This conclusion was presented as an update to the full NOSB at the Fall 2017 NOSB meeting. The 

NOSB unanimously voted to reinstate continue this listing at § 205.601© in 2018.

There was continued support for this material to remain on the National List with the current 

annotation. Certifiers, grower groups, and individual growers all submitted comments in favor of 

retaining this material in both locations on the National List (§§ 205.601(b) and 205.601(c)). While some 

stated there was currently not much use of this material in organic crop production, they also stated it 

should continue to be allowed for those who wish to continue using it. One certifier noted that 

newspaper could be included in manure that is cleaned out of livestock barns, supporting the relisting as 

a compost feedstock.

At the Spring 2023 NOSB meeting, the full Board discussed this material at some length. Discussion 

focused on whether it is reasonable to assume that all/most newspaper and other recycled paper would 

be produced with the inks required by the annotation and, if not, how that would create issues for 

certifiers. This discussion continued in subcommittee after the Spring 2023 meeting, noting that the 

assumption that all recycled paper is using less-problematic inks may not be correct. The Board 

considered whether the listing also included cardboard and confirmed its understanding that it did. The 

Board also discussed the separate Spring 2021 vote to approve paper pots and paper-based planting 

aids and the findings during that process that some of the materials of potential concern found in paper 

pots are also the components of newspaper and other recycled paper. Finally, the board noted that 

municipal compost is allowed within organic production and could, thus, include some of the elements 

of potential concern by virtue of newspaper being a municipal compost feedstock in certain contexts. 

The Board acknowledged that it would be extremely helpful to understand this issue in terms of what 
substances are present at the end of the compost process as a means of understanding whether and 

what adverse impact may result.

Questions to our Stakeholders:

1. Should there be an annotation for this listing that attempts to further clarify what uses are 

acceptable within organic production? Can certifiers appropriately oversee the ink requirement in 

this annotation?

2. How widely used are these materials in organic production?

3. What is the scale of use of this material for this purpose in organic production (specifically number 

of users, farms, acres, geographical reach)?

Public comments on this material have been clear: this is an important material for many growers, 

particularly small producers, but there is concern that materials of concern (for example, PFAS) may be 

present in newspaper and other recycled paper and that certifiers have difficulty inspecting this material 

despite seeing it on many OSPs. Several commenters have called for caution in using this material, or to 

elevate it on the NOSB’s work agenda (it will be part of the NOSB’s compost work agenda item for 2024, 

which could have implications for this listing as well). Discussion at the Fall 2023 NOSB meeting reflected 

these challenges noted by the stakeholder community, but support for relisting was clear.

Justification for Vote:

The NOSB finds newspaper or other recycled paper, without glossy or colored inks compliant with the 

Organic Foods Production Act (OFPA) and/or 7 CFR205.601(c) and is not proposing removal.

NOSB Vote:

Motion to remove newspaper or other recycled paper, without glossy or colored inks from the National 

List 7 CFR 205.601(c)

Motion by: Wood Turner

Seconded by: Jerry D’Amore

Yes: 0 No: 12 Abstain: 1 Recuse: 0 Absent: 2

Motion failed

Plastic mulch and covers

Reference: 205.601(b) As herbicides, weed barriers, as applicable. 

(2) Mulches. (ii) Plastic mulch and covers (petroleum-based other than polyvinyl chloride (PVC)).

Technical Report: 1995 TAP

Petition(s): N/A

Past NOSB Actions: 11/1995 NOSB minutes and vote (pg. 20); 11/2005 NOSB sunset recommendation; 

04/2011 NOSB sunset recommendation; 10/2015 NOSB sunset recommendation; 10/2018 NOSB sunset 

recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Sunset renewal 

notice published 10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); 

Sunset renewal notice published 03/15/2017 (82 FR 14420); Sunset renewal notice published 

05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025
NOSB Review:

Use:

Plastic mulches and covers provide multiple functions in organic production including, but not limited to, 

weed barrier, soil, nutrient and water retention, soil warming, soil solarizing, high and low tunnels, and 

reflective barriers for insect pests. 

Manufacture:

Plastic mulches and covers are thermoplastic resins of high melt viscosity, usually polyethylene. Resin 

pellets are melted into an extruder and pumped or blown through a die or tube to form the plastic in 

the desired shape.

International Acceptance:

Canadian General Standards Board Permitted Substances List

Plastic mulches: non-biodegradable and semi-biodegradable materials shall not be incorporated into the 

soil or left in the field to decompose. Use of polyvinyl chloride as plastic mulch or row cover is 

prohibited.

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

No reference

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (CXG 32-1999)

No reference

International Federation of Organic Agriculture Movements (IFOAM) Norms

No reference

Japan Agricultural Standard (JAS) for Organic Production

Plastic mulch (limited to those to be removed after use)

Environmental Issues:

Although there is significant support for its relisting, plastic mulch has many environmental concerns, 

most of which are related to disposal after each season. The recycling of plastic mulch seems to be a 

diminishing option. The product is easily damaged and contaminated, which makes recycling a less 

viable option. Other concerns include the breakdown of microplastics and litter from damaged product 

remaining in the field. These pieces are considered foreign materials and contaminate organic soils. The 

labor cost to remove plastic is very expensive and often is a challenge for growers. Because of this, many 

growers are excited for the development of biodegradable mulches.

Discussion:

The Crops Subcommittee discussed the use, manufacturing, and environmental issues with plastic 

mulches. The expansiveness of the listing and annotations were reviewed, and it was noted that the 

term, “covers,” can refer to high and low tunnels as well as ground coverings. Members of the 

Subcommittee discussed the significance of recycling as a diminishing option and reviewed the social 

concerns about recycling of plastic mulches not being a viable option. Many members of the 

Subcommittee have expressed concern in the lack of progress in reducing the dependency of plastic 

mulch and covers in certain areas of organic production.
Plastic mulch is discussed directly in the Organic Foods Production Act (OFPA). OFPA 6508(c)(2) prohibits 

the use plastic mulches unless such mulches are removed at the end of each growing or harvest season. 

Because of this listing, plastic mulch is also found in the crop, pest, weed and disease management 

practice standard under §205.206(c)(6):

Plastic or other synthetic mulches: Provided, That, they are removed from the field at the end of 

the growing or harvest season.

Under this Practice Standard listing, all synthetic mulches are permitted. The listing for Plastic Mulch and 

Covers in the National List (§205.601(b)(2)(ii)) broadens the allowance of “plastic or other synthetic 

mulches” to include “covers” and prohibits polyvinyl chloride (PVC).

Questions to our Stakeholders:

1. Which crops depend most on plastic mulch, and why?

2. What alternatives are there for weed management?

Justification for Vote:

After much discussion, the Subcommittee concluded that removing plastic mulch and covers from the 

National List would not prohibit the use of plastic mulch in organic production. If plastic mulch and 

covers were removed from the National List, all plastic mulches would be allowed, due to the allowance 

of plastic mulch in OFPA and the organic regulation practice standard at §205.206. Additionally, 

removing plastic mulch and covers from the National List would remove the prohibition of PVC-based 

mulch., therefore allowing PVC mulch to be used. While there is strong support in the Subcommittee to 

encourage organic producers to reduce their dependency on plastic mulch and covers, the 

Subcommittee does not intend to remove a restrictive annotation that keeps PVC mulch out of organic 

production.

The Subcommittee vote was ambiguous, however, at this time, it finds plastic mulches and covers 

compliant with the Organic Foods Production Act (OFPA) and/or 7 CFR 205.600 and is not proposing 

removal.

The Board discussion at the Fall 2023 meeting raised similar discussions and questions. One Board 

member suggested the idea of working on plastic as a weed management agenda item, to initiate 

research to reduce dependency on this material. In totality, plastic mulch is a small percentage of the 

total plastic use in the organic industry. There is heavy use in livestock and handling (packaging) but 

these materials are not listed. Restricting growers from using a material currently understood as 

necessary to help reduce plastic use is not equitable. Plastic reduction needs to be approached 

holistically. 

NOSB Vote:

Motion to remove plastic mulch and covers from the National List

Motion by: Logan Petrey

Seconded by: Mindee Jeffery

Yes: 1 No: 12 Abstain: 0 Recuse: 0 Absent: 2

Motion failed
Aqueous potassium silicate

Reference: 205.601(e) As insecticides (including acaricides or mite control). 

(2) Aqueous potassium silicate (CAS #-1312-76-1)—the silica, used in the manufacture of potassium 

silicate, must be sourced from naturally occurring sand.

Technical Report: 2003 TAP; 2014 TR; 2023 Limited Scope TR

Petition(s): 2002; 2006 (Addendum #1)

Past NOSB Actions: 11/2007 NOSB recommendation; 10/2014 NOSB sunset recommendation; 10/2018 

NOSB sunset recommendation

Regulatory Background: Added to National List 12/13/2010 (75 FR 77521); Sunset renewal notice 

published 06/19/2015 (80 FR 35177); Sunset renewal notice published 05/07/2020 (85 FR 27105). 

Sunset Date: 6/22/2025

NOSB Review:

Use:

Aqueous potassium silicate is used as an insecticide for insects and mites. Formulations of aqueous 

potassium silicate are either sprayed on the foliage of plants or incorporated in the soil with the goal of 

plant uptake across root and leaf boundaries. The silica tetrahedra are purported to be incorporated in 

boundary cells (in roots and leaves) inhibiting insect feeding and the onset of plant disease infection. 

The action of applying potassium silicate in a foliar spray serves to induce production of phytoalexins, 

chitinases and that in turn strengthen stroma and cell walls.

Manufacture:

Aqueous potassium silicate is manufactured by combining high purity silica sand and potassium 

carbonate (both mined materials) and heating to a high temperature (2000 degrees F). The potassium 

carbonate and silicon dioxide fuse to form a molten potassium silicate glass with the evolution of carbon 

dioxide gas. This glass can either be 1) cooled and ground into a powder or 2) dissolved in water to form 

a potassium silicate solution. The solution may subsequently be spray dried to form hydrous powder 

granules of potassium silicate.

International Acceptance:

Canadian General Standards Board Permitted Substances List

Potassium silicate is listed as approved for crop protection.

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

No silicates were listed at this website.

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

Silicates allowed only as ground powders.

International Federation of Organic Agriculture Movements (IFOAM)

Silicates are allowed as plant protectants. 

Japan Agricultural Standard (JAS) for Organic Production

No information found.
Environmental and Health Issues:

The 2014 Technical Report (TR) states that:

● “Potassium silicate will not adversely affect birds.”

● It is “practically non-toxic to fish.”

● “Potassium silicate is not toxic to honeybees at the concentration administered for the foliar 

spray.”

● “The overall toxicological risk from human exposure to potassium silicate is negligible.”

● “Risks from aggregate exposure via oral, dermal and inhalation exposure are ... considered 

negligible.”

Discussion:

Written comments submitted to the NOSB prior to the April 2023 NOSB meeting were mostly in favor of 

relisting, with 4 in favor, 1 opposed, and 1 unclear.

Based on information in the 2014 TR, concerns were raised by NOSB members in 2018, during the 2020 

sunset review. Concerns raised by the NOSB included:

1. Skin irritation from handling aqueous potassium silicate.

2. Effects on farmworkers making the foliar application.

3. Effects on human or animal consumers because of its reported effect of making forage plants 

less digestible.

4. Its reported effect of elongation and thickening of stems.

5. Delayed antithesis and flower deformation in some plant species.

6. Whether it is essential to and compatible with organic production.

Following up on these concerns (please refer to the 2014 TR for references):

● Investigation of the effect of aqueous potassium silicate on flowers showed that the articles 

cited (TR pp. 487-490) were greenhouse studies in soilless media. One study showed that 

applications of potassium silicate “either increased or decreased height, diameter, fresh weight, 

dry weight, flower diameter, and leaf thickness.” The other study found that drenches with 

higher rates of potassium silicate resulted in stunted plants with deformed flowers. However, 

substrate pH was not carefully controlled with the addition of such high-pH drenches. These 

studies have little to do with use of aqueous potassium silicate as a foliar spray in organic 

agriculture.

● Similarly, the study (TR pp. 477-481) showing that aqueous potassium silicate could make 

forages “more difficult to chew and digest” was unrelated to the use pattern of aqueous 

potassium silicate in organic agriculture. The study looked at forages harvested at different 

growth stages and showed that overmature grass forages contained high levels of silicon and 

were less digestible.

● A new, 2023 limited scope TR says that aqueous potassium silicate does not present an 

inhalation hazard to farmworkers.

● Aqueous potassium silicate products are used by some organic fruit and vegetable growers. 

Public comments that these organic producers submitted to the NOSB prior to the April 2023 

NOSB Meeting did not report adverse effects on their produce, in contrast to the suggestion (TR 

pp. 479-481) that produce might become less palatable. On the contrary, they advocated for its 

relisting. One grower reported that two early sprays of aqueous potassium silicate eliminated 

several late sprays of sulfur.
The Subcommittee requested a limited scope technical report (TR) in 2022 to address the following 

questions:

1. What is the fate of potassium silicate on the plant leaf surface? When sprayed, potassium 

silicate dries on the leaves. What happens to it there? Does it stay in that form for several days 

and act as a barrier? Does it transform and become absorbed into the plant as silicic acid? Does 

it re-dissolve and run off to the ground in rains?

2. What is its effect on the plant leaf microbial community?

3. When sprayed under low humidity conditions, can aqueous potassium silicate crystallize in the 

air and present an inhalation hazard?

The 2023 limited scope TR indicated that aqueous potassium silicate was very unlikely to be hazardous 

to the applicator. Its presence on leaves tends to favor bacterial over fungal organisms, which may 

account for some of its fungicidal effects. Its fate on the leaf surface is highly dependent on the pH of 

the spray mixture. At lower pH values, close to 5, aqueous potassium silicate may be deposited just 

below the leaf cuticle layer and present a barrier to fungus infection. At higher pH values, surface 

deposits (quickly washed off by rain or irrigation) may perform the same function. The 2023 limited 

scope TR mentioned that aqueous potassium silicate in spray solution can form nanoparticles, but these 

are common in nature. The TR did not mention any adverse effects from nanoparticles.

The 2023 limited scope TR clarified important points and did not report any negative information 

regarding the safety of the product. Reviewing its environmental and health effects, the Crops NOSB 

finds that aqueous potassium silicate is compatible with organic agriculture.

Written comments for the October 2023 NOSB meeting included 3 in favor of relisting aqueous 

potassium silicate for this use, and one opposed. There were over 230 listings noted on organic system 

plans for both uses. The key points in the discussion above were reviewed, including clarification of the 

research article on digestibility of forages.

Justification for Vote:

The NOSB finds aqueous potassium silicate compliant with the Organic Foods Production Act (OFPA) 

and/or 7 CFR 205.600 and is not proposing removal.

 

NOSB Vote:

Motion to remove aqueous potassium silicate from the National List at § 205.601(e)(2)

Motion by: Brian Caldwell

Seconded by: Wood Turner

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed
Aqueous potassium silicate

Reference: 205.601(i) As plant disease control. 

(1) Aqueous potassium silicate (CAS #-1312-76-1)—the silica, used in the manufacture of potassium 

silicate, must be sourced from naturally occurring sand.

Technical Report: 2003 TAP; 2014 TR; 2023 Limited Scope TR

Petition(s): 2002; 2006 (Addendum #1)

Past NOSB Actions: 11/2007 NOSB recommendation; 10/2014 NOSB sunset recommendation; 10/2018 

NOSB sunset recommendation

Regulatory Background: Added to National List 12/13/2010 (75 FR 77521); Sunset renewal notice 

published 06/19/2015 (80 FR 35177); Sunset renewal notice published 05/07/2020 (85 FR 27105). 

Sunset Date: 6/22/2025

NOSB Review:

Use:

Aqueous potassium silicate is used as a crop protectant for disease control and suppression. 

Formulations of aqueous potassium silicate are either sprayed on the foliage of plants or incorporated in 

the soil with the goal of plant uptake across root and leaf boundaries. The silica tetrahedra are 

purported to be incorporated in boundary cells (in roots and leaves) inhibiting insect feeding and the 

onset of plant disease infection. The action of applying potassium silicate in a foliar spray serves to 

induce production of phytoalexins, chitinases and that in turn strengthen stroma and cell walls.

Manufacture:

Aqueous potassium silicate is manufactured by combining high purity silica sand and potassium 

carbonate (both mined materials) and heating to a high temperature (2000 degrees F). The potassium 

carbonate and silicon dioxide fuse to form a molten potassium silicate glass with the evolution of carbon 

dioxide gas. This glass can either be 1) cooled and ground into a powder or 2) dissolved in water to form 

a potassium silicate solution. The solution may subsequently be spray dried to form hydrous powder 

granules of potassium silicate.

International Acceptance:

Canadian General Standards Board Permitted Substances List

Potassium silicate is listed as approved for crop protection.

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

No silicates were listed at this website.

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

Silicates allowed only as ground powders.

International Federation of Organic Agriculture Movements (IFOAM)

Silicates are allowed as plant protectants.

Japan Agricultural Standard (JAS) for Organic Production

No information found.
Environmental and Health Issues

The 2014 Technical Report (TR) states that:

● “Potassium silicate will not adversely affect birds.”

● It is “practically non-toxic to fish.”

● “Potassium silicate is not toxic to honeybees at the concentration administered for the foliar 

spray.”

● “The overall toxicological risk from human exposure to potassium silicate is negligible.”

● “Risks from aggregate exposure via oral, dermal and inhalation exposure are ... considered 

negligible.”

Discussion:

Written comments submitted to the NOSB prior to the April 2023 NOSB meeting were mostly in favor of 

relisting, with 4 in favor, 1 opposed, and 1 unclear.

Based on information in the 2014 TR, concerns were raised by NOSB members in 2018, during the 2020 

sunset review. Concerns raised by the NOSB included:

1. Skin irritation from handling aqueous potassium silicate.

2. Effects on farmworkers making the foliar application.

3. Effects on human or animal consumers because of its reported effect of making forage plants 

less digestible.

4. Its reported effect of elongation and thickening of stems.

5. Delayed antithesis and flower deformation in some plant species.

6. Whether it is essential to and compatible with organic production.

Following up on these concerns (please refer to the 2014 TR for references):

● Investigation of the effect of aqueous potassium silicate on flowers showed that the articles 

cited (TR pp. 487-490) were greenhouse studies in soilless media. One study showed that 

applications of potassium silicate “either increased or decreased height, diameter, fresh weight, 

dry weight, flower diameter, and leaf thickness.” The other study found that drenches with 

higher rates of potassium silicate resulted in stunted plants with deformed flowers. However, 

substrate pH was not carefully controlled with the addition of such high-pH drenches. These 

studies have little to do with use of aqueous potassium silicate as a foliar spray in organic 

agriculture.

● Similarly, the study (TR pp. 477-481) showing that aqueous potassium silicate could make 

forages “more difficult to chew and digest” was unrelated to the use pattern of aqueous 

potassium silicate in organic agriculture. The study looked at forages harvested at different 

growth stages and showed that overmature grass forages contained high levels of silicon and 

were less digestible.

● A new, 2023 limited scope TR says that aqueous potassium silicate does not present an 

inhalation hazard to farmworkers.

● Aqueous potassium silicate products are used by some organic fruit and vegetable growers. 

Public comments that these organic producers submitted to the NOSB prior to the April 2023 

NOSB Meeting did not report adverse effects on their produce, in contrast to the suggestion (TR 

pp. 479-481) that produce might become less palatable. On the contrary, they advocated for its 

relisting. One grower reported that two early sprays of aqueous potassium silicate eliminated 

several late sprays of sulfur.
The Subcommittee requested a limited scope technical report (TR) in 2022 to address the following 

questions:

1. What is the fate of potassium silicate on the plant leaf surface? When sprayed, potassium 

silicate dries on the leaves. What happens to it there? Does it stay in that form for several days 

and act as a barrier? Does it transform and become absorbed into the plant as silicic acid? Does 

it re-dissolve and run off to the ground in rains?

2. What is its effect on the plant leaf microbial community?

3. When sprayed under low humidity conditions, can aqueous potassium silicate crystallize in the 

air and present an inhalation hazard?

The 2023 limited scope TR indicated that aqueous potassium silicate was very unlikely to be hazardous 

to the applicator. Its presence on leaves tends to favor bacterial over fungal organisms, which may 

account for some of its fungicidal effects. Its fate on the leaf surface is highly dependent on the pH of 

the spray mixture. At lower pH values close to 5, aqueous potassium silicate may be deposited just 

below the leaf cuticle layer and present a barrier to fungus infection. At higher pH values, surface 

deposits (quickly washed off by rain or irrigation) may perform the same function. The 2023 limited 

scope TR mentioned that aqueous potassium silicate in spray solution can form nanoparticles, but these 

are common in nature. The TR did not mention any adverse effects from nanoparticles.

The 2023 limited scope TR clarified important points and did not report any negative information 

regarding the safety of the product. Reviewing its environmental and health effects, the Crops NOSB 

finds that aqueous potassium silicate is compatible with organic agriculture.

Written comments for the October 2023 NOSB meeting included 4 in favor of relisting aqueous 

potassium silicate for this use, and one opposed. There were over 230 listings noted on organic system 

plans for both uses. The key points in the discussion above were reviewed, including clarification of the 

research article on digestibility of forages. 

Justification for Vote:

The NOSB finds aqueous potassium silicate compliant with the Organic Foods Production Act (OFPA) 

and/or 7 CFR 205.600 and is not proposing removal.

NOSB Vote::

Motion to remove aqueous potassium silicate from the National List at § 205.601(i)(1)

Motion by: Brian Caldwell

Seconded by: Jerry D’Amore

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed
Elemental sulfur

Reference: 205.601(e) As insecticides (including acaricides or mite control). (5) Elemental sulfur.

Reference: 205.601(i) As plant disease control. (10) Elemental sulfur.

Reference: 205.601(j) As plant or soil amendments. (2) Elemental sulfur.

Technical Report: 1995 TAP; 2018 TR

Petition(s): 2017 (slug or snail bait, separate sunset review)

Past NOSB Actions: 04/1995 NOSB minutes and vote (pg. 345); 11/2005 NOSB sunset recommendation; 

04/2010 NOSB sunset recommendation; 10/2010 NOSB sunset recommendation; 10/2015 NOSB sunset 

recommendation; 10/2018 NOSB sunset recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Sunset renewal 

notice published 10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); 

Sunset renewal notice published 03/15/2017 (82 FR 14420); Sunset renewal notice published 

05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

Approved legal uses of the substance (TR 67-75): Elemental sulfur is currently on the National List of 

Allowed and Prohibited Substances as a synthetic substance allowed for use in organic crop production 

for the following categories: 

1. For uses as an insecticide, including acaricides or mite control (7 CFR 205.601 (e)(5). 

2. For plant disease control (7 CFR 205.601(i)(10)). 

3. As plant or soil amendments (7 CFR 205.601(j)(2)). 

The current sunset review includes all three listings of sulfur, used as an insecticide, plant disease 

control, and as a plant or soil amendment. 

Sulfur is an essential plant nutrient, naturally present in our food and soil, and is part of normal human 

biochemistry. When sulfur is used as a soil amendment it can have a strong acidifying effect by 

replacing sodium with calcium in high pH alkali soils. Sulfur is considered the fourth major plant 

nutrient after nitrogen, phosphorus, and potassium-. Sulfur can also be used to control insects and/or 

diseases. It is approved for use on conventional and organic crops to help control fungi and other pests 

and is commonly used on farms domestically and internationally.

Manufacture:

Sulfur is one of few elements found in its elemental form in nature, typically in limestone/gypsum 

formations, limestone/anhydrite formations associated with salt domes, or volcanic rock (d'Aquin 2007). 

Currently, elemental sulfur is produced as a by-product from natural gas or petroleum operations and 

refinery processes. The latter is the primary source of most elemental sulfur currently being used.

International Acceptance:

Canadian General Standards Board Permitted Substances List
Sulfur is allowed by the Canadian Organic Standards. The Canadian General Standards Board (CGSB) 

includes non-synthetic elemental sulfur as a permitted substance for organic production systems 

(CAN/CGSB-32.311-2015) for use as a soil amendment and as a foliar application. The CGSB also permits 

using sulfur to control external parasites and sulfur smoke bombs in conjunction with other methods 

used for rodent control when a pest control program is temporarily overwhelmed. 

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

European Economic Community (EEC) Council Regulation (EEC No 2092/91), carried over by Article 

16(3)(c) of Regulation No 834/2007, permits the use of sulfur as a fungicide, acaricide, and repellent in 

organic food production. 

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

Codex Alimentarius Commission (CAC GL 32-1999) permits the use of sulfur for pest and disease control 

when the certification body or authority recognizes the need for plant protection (Codex, 2013). 

International Federation of Organic Agriculture Movements (IFOAM)

The International Federation of Organic Agriculture Movements (IFOAM) lists sulfur as an approved 

substance for use as pest and disease control, fertilizer/soil conditioner, and crop protectant and growth 

regulator. 

Japan Agricultural Standard (JAS) for Organic Production

The Japan Agricultural Standard (JAS) for Organic Production (Notification No. 1605 of 2005) permits the 

use of sulfur as a fertilizer or soil improvement substance and as a substance for plant pest and disease 

control. 

Environmental Issues:

Elemental sulfur is relatively innocuous in the environment when used according to the product label. It 

is also low in toxicity. It should not be used within one month of any horticultural oil product, as 

currently stated on most sulfur labels. 

An updated Technical Report (TR) was completed on April 19, 2018. There was no new information 

contradicting historical information that characterizes sulfur as an important and relatively safe material 

for organic agriculture. 

Although low in acute toxicity, sulfur is a respiratory, ocular, and dermal irritant that can significantly 

impact farmworker health. Farmworker exposures can be mitigated if label recommendations and 

proper PPE recommendations are followed. 

Discussion:

2018 NOSB Review: Historically, there has been strong support for the continued listing of sulfur, 

particularly for use against various bacterial and fungal diseases, insects, and as a plant and soil 

amendment. It was noted that several agricultural commissioners in California had encouraged a shift 

to wettable formulations in vineyard applications, and anecdotal information suggests fewer drift and 

regulatory problems. 

Based on the extensive public comment and discussions, new technical reviews, previous committee 

votes & discussions, and historical public comment, the 2018 NOSB review concluded that elemental 
sulfur still appears to be necessary in organic crop production. The NOSB should continue to monitor 

sulfur use in organic agriculture and respond to any new information raising environmental or, in 

particular, public health concerns.

2023 NOSB Review: The NOSB reviewed all three listings for elemental sulfur. In the public comments, 

farmer advocacy groups and consultants spoke about the importance of this substance, that elemental 

sulfur has been included on the original national list since 1995, and that alternatives are not as 

effective. 

There were a few comments from advocacy groups that wanted further annotations for worker 

protection due to respiratory concerns, and potential limits to control heavy contamination since 

synthetic elemental sulfur comes from scrubbers from fossil fuel plants. The Board reviewed in further 

detail respiratory concerns and the potential increased risk that children have, and discussed both a 

journal article, and a study completed at Oregon State University about the effects on children’s 

respiratory health. 

The Board also reviewed the insight gained from the question regarding the use of wettable sulfur 

products. Some in the community favored a potential annotation, however it was learned that it is 

common for produce growers to use both dusting sulfur and wettable sulfur in rotation with each other 

due to different efficacies. When fruit is present, wettable formulations increase the risk of residue on 

the fruit, and specialized application equipment for dusting sulfur can be used to reduce dusting sulfur 

drift. 

NOTE: in the listing at 205.601(e), the Board recommends consistency with definitions -As acaricides 

need not be insecticides and insecticides need not be acaricides. During the review, the NOP suggested 

that this could be a technical correction as part of the inerts rulemaking. 

At the Fall 2023 NOSB meeting, the Board reviewed elemental sulfur. Many farmer commenters and 

groups that represent farmer stakeholders expressed the support for elemental sulfur, highlighting that

its performance is superior compared to alternatives for pest and disease mitigation, and also that it is 

an essential plant nutrient. The NOSB also reviewed community suggestions for annotations including 

increased worker protections due to respiratory concerns and contamination. 

Justification for Vote: 

The NOSB finds all listings of elemental sulfur compliant with the Organic Foods Production Act (OFPA) 

and/or 7 CFR 205.600 and is not proposing removal.

NOSB Vote:: 

Motion to remove elemental sulfur from the National List at 205.601(e)

Motion by: Amy Bruch

Seconded by: Mindee Jeffery

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

NOSB Vote:: 

Motion to remove elemental sulfur from the National List at 205.601(i)

Motion by: Amy Bruch

Seconded by: Wood Turner

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2
NOSB Vote:: 

Motion to remove elemental sulfur from the National List at 205.601(j)

Motion by: Amy Bruch

Seconded by: Mindee Jeffery

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motions failed

Lime sulfur

Reference: 205.601(e) As insecticides (including acaricides or mite control). (6) Lime sulfur—including 

calcium polysulfide.

Technical Report: 2014 TR

Petition(s): N/A

Past NOSB Actions: Actions: 04/1995 NOSB minutes and vote (pg. 341); 11/2005 NOSB sunset 

recommendation; 10/2010 NOSB sunset recommendation; 10/2015 NOSB sunset recommendation; 

10/2018 NOSB sunset recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Sunset renewal 

notice published 10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); 

Sunset renewal notice published 03/15/2017 (82 FR 14420); Sunset renewal notice published 

05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

Lime sulfur is on the National List at §205.601(e)(6) as an insecticide (including acaricide or mite control) 

and at §205.601 (j)(6) for plant disease control. As an insecticide, lime sulfur is used to control mites 

(spider mites and rust mites), aphid, and San Jose scale in tree fruit and other organic crops.

Manufacture:

Lime sulfur is often referred to by its chemical name, calcium polysulfide. It is considered to be synthetic 

and is produced by reacting boiling calcium hydroxide [CaOH22] and ground sulfur (2014 TR).

International Acceptance:

Canadian General Standards Board Permitted Substances List 

Allowed as a production aid

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Permits the use of lime sulphur (calcium polysulfide) as a fungicide, insecticide, acaricide. 

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

Does not appear on this listing
International Federation of Organic Agriculture Movements (IFOAM)

Allowed as a crop protectant

Japan Agricultural Standard (JAS) for Organic Production

Lime sulfur powder allowed as Substances for Plant Pest and Disease Control

Environmental Issues:

Residues of lime sulfur are exempt from the requirement of a tolerance under 40 CFR 180.1232 as 

determined by the U.S. EPA because the calcium polysulfides found in lime sulfur products rapidly 

degrade to calcium hydroxide and sulfur in the environment and human body.

Discussion:

All public commenters were in favor of relisting lime sulfur for control of fungal and bacterial diseases as 

well as its uses for various insects. One commenter requested specifying only essential uses. Use is 

widespread across many crops and regions, and many comments note that there are not viable 

alternatives for its various uses. 

Lime sulfur can cause phytotoxicity in some crops, however, rate and timing of application can be used 

to avoid this problem. In fact, lime sulfur pesticide applications during and shortly after bloom can have 

a desirable crop-thinning effect on apples. The TR notes that lime sulfur may impair some beneficial 

insects and mites, but timing of use can minimize the negative effects. It also noted potential human 

health concerns from lime sulfur primarily due to the highly caustic nature of the undiluted product or 

the release of hydrogen sulfide. This concern can be mitigated if proper safety procedures are followed 

during mixing and label directions including personal protective equipment (PPE) are followed. The TR 

also provided an extensive list of alternative materials and practices, however, if an outbreak of mites or 

scale occurs, lime sulfur is an effective option.

The Crops Subcommittee (CS) discussion noted that some label-allowed uses of lime sulfur could 

negatively affect beneficial arthropods. To avoid this, the CS requested a separate work agenda item for 

an annotation change regarding timing and rates of lime sulfur use. 

Written comments for the October 2023 NOSB meeting included 10 in favor of relisting lime sulfur for 

this use, and none opposed. One commenter requested an annotation to use proper timing to prevent 

damage to beneficial insect populations. There were over 280 listings noted on organic system plans for 

both uses. 

Justification for Vote: 

The NOSB finds lime sulfur compliant with the Organic Foods Production Act (OFPA) and/or 7 

CFR205.600 and is not proposing removal.

 

NOSB Vote:

Motion to remove lime sulfur from the National List at 205.601(e)(6)

Motion by: Brian Caldwell

Seconded by: Jerry D’Amore

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed
Lime sulfur

Reference: 205.601(i) As plant disease control. (6) Lime sulfur.

Technical Report: 2014 TR

Petition(s): N/A

Past NOSB Actions: Actions: 04/1995 NOSB minutes and vote (pg. 341); 11/2005 NOSB sunset 

recommendation; 10/2010 NOSB sunset recommendation; 10/2015 NOSB sunset recommendation; 

10/2018 NOSB sunset recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Sunset renewal 

notice published 10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); 

Sunset renewal notice published 03/15/2017 (82 FR 14420); Sunset renewal notice published 

05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

Lime sulfur is on the National List at §205.601(e)(6) as an insecticide (including acaricide or mite control) 

and at §205.601 (j)(6) for plant disease control. As a fungicide, it is used to control powdery mildew, 

anthracnose, scab, peach leaf curl, fire blight, and several other plant diseases in tree fruit and berry 

crops. 

Manufacture:

Lime sulfur is often referred to by its chemical name, calcium polysulfide. It is considered to be synthetic 

and is produced by reacting boiling calcium hydroxide [CaOH22] and ground sulfur (2014 TR).

International Acceptance:

Canadian General Standards Board Permitted Substances List 

Allowed as a production aid

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Permits the use of lime sulphur (calcium polysulfide) as a fungicide, insecticide, acaricide. 

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

Does not appear on this listing

International Federation of Organic Agriculture Movements (IFOAM)

Allowed as a crop protectant

Japan Agricultural Standard (JAS) for Organic Production

Lime sulfur powder allowed as Substances for Plant Pest and Disease Control
Environmental Issues:

Residues of lime sulfur are exempt from the requirement of a tolerance under 40 CFR 180.1232 as 

determined by the U.S. EPA because the calcium polysulfides found in lime sulfur products rapidly 

degrade to calcium hydroxide and sulfur in the environment and human body.

Discussion:

All public commenters were in favor of relisting lime sulfur for control of fungal and bacterial diseases as 

well as its uses for various insects. One commenter requested specifying only essential uses. Use is 

widespread across many crops and regions, and many comments note that there are not viable 

alternatives for its various uses. 

Lime sulfur can cause phytotoxicity in some crops, however, rate and timing of application can be used 

to avoid this problem. In fact, lime sulfur pesticide applications during and shortly after bloom can have 

a desirable crop-thinning effect on apples. The TR notes that lime sulfur may impair some beneficial 

insects and mites, but timing of use can minimize the negative effects. It also noted potential human 

health concerns from lime sulfur primarily due to the highly caustic nature of the undiluted product or 

the release of hydrogen sulfide. This concern can be mitigated if proper safety procedures are followed 

during mixing and label directions including personal protective equipment (PPE) are followed. The TR 

also provided an extensive list of alternative materials and practices; however, an important benefit of 

lime sulfur is that it can be effective even after a fungus infection has taken place. Almost all other 

organic alternatives have only preventative action. 

The Crops Subcommittee (CS) discussion noted that some label-allowed uses of lime sulfur could 

negatively affect beneficial arthropods. To avoid this, the CS requested a separate work agenda item for 

an annotation change regarding timing and rates of lime sulfur use. 

Written comments for the October 2023 NOSB meeting included 9 in favor of relisting lime sulfur for this 

use and none opposed. One commenter requested an annotation to use proper timing to prevent 

damage to beneficial insect populations. There were over 280 listings noted on organic system plans for 

both uses. 

Justification for Vote: 

The NOSB finds lime sulfur compliant with the Organic Foods Production Act (OFPA) and/or 7 CFR 

205.600 and is not proposing removal.

 

NOSB Vote:

Motion to remove lime sulfur from the National List at 205.601(i)(6)

Motion by: Brian Caldwell

Seconded by: Jerry D’Amore

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed

Hydrated lime

Reference: 205.601(i) As plant disease control. 

(4) Hydrated lime.

Technical Report: 1995 TAP; 2001 TAP; 2002 TR (calcium hydroxide); 2015 TR (Livestock)

Petition(s): N/A
Past NOSB Actions: 04/1995 NOSB minutes and vote (pg. 345); 04/2006 sunset recommendation; 

10/2010 NOSB sunset recommendation; 10/2015 NOSB sunset recommendation; 10/2018 NOSB sunset 

recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Technical 

correction annotation change published 10/31/2003 (68 FR 61987); Sunset renewal notice published 

10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); Sunset renewal 

notice published 03/15/2017 (82 FR 14420); Sunset renewal notice published 05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

Hydrated lime is a synthetic substance limited for use in organic crop production for plant disease 

control (7 CFR 205.601(i)(4). It is also allowed as an external pest control in livestock production 21 (7 

CFR 205.603(b)(5)). Regarding livestock applications, the final rule states that hydrated lime may not be 

used to cauterize physical alterations (medical treatment) or deodorize animal wastes. Hydrated Lime, 

also known as calcium hydroxide, is listed for handling as an allowed synthetic, nonagricultural 

substance which may be used as an ingredient in or on processed products (7 CFR 205.605(b)(8).

Manufacture:

According to the technical review (TR), the “industrial production of hydrated/slaked lime involves two 

elementary reactions beginning with naturally occurring limestone deposits. In the first step, ground 

limestone—which contains predominantly calcium carbonate (CaCO3) with smaller amounts of 

magnesium, silicon, aluminum and iron oxide compounds—is thermally transformed into quicklime 

(Oates, 2010). Specifically, heating raw or minimally processed limestone to temperatures in excess of 

900 oC results in conversion of the calcium carbonate content of limestone to calcium oxide (CaO) in a 

material known as quicklime (equation 1). This thermal transformation occurs with liberation of carbon 

dioxide (CO2) gas. In the slaking process, quicklime reacts exothermically (releases heat) with two 

equivalents of water to produce hydrated/slaked lime consisting primarily of calcium hydroxide 

[Ca(OH)2] (equation 2). The normal hydration process is carried out at atmospheric pressure and 

temperatures of approximately 100 oC (Kenny & Oates, 2007). A variation of the normal hydration 

process involves reaction of quicklime and water under a high steam pressure of up to 1 MPa and at 

temperatures approaching 180 oC to form hydrates. After hydration, the hydrated lime product is dried, 

milled, and air classified” (TR 231-243).

International Acceptance:

Canadian General Standards Board Permitted Substances List

Hydrated lime is also listed in Section 4.3—Crop Production Aids and Materials—for use as a plant 

disease control agent only (CAN, 2011). Canadian organic regulations also permit the use of hydrated 

lime as a health care product and/or production aid in organic livestock production under Section 5.3 of 

the Permitted Substances Lists. According to this rule, hydrated lime is not allowed for use to cauterize 

physical alterations (medical treatment) or deodorize animal wastes. (2015 TR 177-181)

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Annex I of the European regulations allow “industrial lime from sugar production”—a byproduct of sugar 

production from sugar beet—as a fertilizer or soil conditioner. Calcium hydroxide may be used as a 
fungicide on fruit trees to control Nectria galligena in organic crop production under Annex II and as a 

processing aid in the production of processed organic foods of plant origin under Annex VIII (EC, 2008).

European Union Organic regulations from the European Union do not permit the use of hydrated 

lime/calcium hydroxide 189 as an external parasiticide in livestock production. (TR 188-93)

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (CXG 32-1999)

The Codex Guidelines for the Production, Processing, Labeling and Marketing of Organically Produced 

Foods (CAC/GL 32-1999) do not list hydrated lime/calcium hydroxide for use in organic livestock or crop 

production. However, calcium hydroxide is included in the list of “processing aids which may be used for 

the preparation of products of agricultural origin referred to in Section 3 of these guidelines” (Codex, 

2013). (TR 183-86)

International Federation of Organic Agriculture Movements (IFOAM) Norms

IFOAM Norms permit the use of “milk of lime” (i.e., hydrated/slaked lime, calcium hydroxide) for pest 

and disease control and disinfection in livestock housing and equipment (Appendix 5). Likewise, calcium 

hydroxide (slaked lime) is included in the “Indicative List of Equipment Cleansers and Equipment 

Disinfectants” (Appendix 4 – Table 2) for organic handling/processing. Calcium hydroxide is also listed as 

an approved food additive for maize tortilla flour and processing aid for sugar (Appendix 4 – Table 1). 

Lastly, application of calcium hydroxide (hydrated lime) is allowed on aerial plant parts only for plant 

disease control according to Appendix 3 of the IFOAM Norms (IFOAM, 2014). Hydrated lime is not 

explicitly listed as an approved miticide according to IFOAM. (TR 201- 208).

Japan Agricultural Standard (JAS) for Organic Production

Calcium hydroxide derived from calcium oxide (slaked lime) is listed in Table 1 of the standard as an 

approved fertilizer and soil improvement substance (JMAFF, 2012). Hydrated lime is not explicitly 

approved as a miticide according to Japanese organic regulations. (TR 195-199)

Environmental Issues:

Hydrated lime is released to the environment through various industrial waste streams and according to

its use in agricultural production. Both calcium and hydroxide—the principal atomic/molecular subunits

of hydrated lime—are abundantly present in natural waters; therefore, it is unlikely that small to

moderate releases will adversely affect the aquatic or terrestrial environment. Large-volume accidental

releases, however, could significantly raise pH of receiving waters and soils, resulting in toxic effects

to non-target organisms. Hydrated lime is considered practically non-toxic to slightly toxic to freshwater

fish and invertebrates when added in quantities that do not lead to significant changes in water pH.

While certain strains of soil bacteria can tolerate extreme pH levels (e.g., pH 1.0 or 11.0), larger softbodied soil organisms are significantly more sensitive to changes in soil pH. Earthworms, for example,

can only survive in the physiological pH range of 4.0 to 8.0. Changes in soil pH due to application of

alkaline hydrated lime can also affect the bioavailability of toxic heavy metal contaminants as well as

essential micronutrients. It is highly unlikely that hydrated lime from livestock treatments will be

released to nearby soils in sufficient quantities to adversely impact the environment. Industrial

production of the chemical precursor, quicklime (CaO), uses considerable amounts of energy and may

release dust into the atmosphere. The use of more efficient modern kilns and bag filters can minimize

the environmental impact of this process.

Discussion:

The Crops Subcommittee (CS) discussed this substance and the way it is listed and used across all areas 

of the National List, including Crops, Livestock, and Handling, on which it is listed as calcium hydroxide. 
Two Technical Advisory Panels (TAPs) and a Technical Report (TR) were compiled in 1995, 2001 and 

2015, respectively. The use of hydrated lime (as has been practiced in organic production) is known to 

be an effective disease suppression practice. A previous sunset review noted that the use of hydrated 

lime in Bordeaux mix to make copper available for disease suppression is highly effective and widely 

used by fruit and vegetable growers. The Subcommittee discussed the history of the substance and 

expressed a desire to receive further information on the current extent of the use of the substance.

Public comments from the Spring 2023 NOSB meeting were supportive of relisting hydrated lime. 

Growers illuminated the importance of this substance in organic tree fruit production to control 

diseases. A producer group emphasized that allowed alternatives such as horticultural oils and 

elemental sulfur may have limited efficacy. Use of the material is important as an ingredient in Bordeaux 

mixes, especially for treating bacterial gummosis in organic cherries. Growers were clear in the 

importance of hydrated lime as a tool for integrated pest management. An association expressed 

support for relisting, reporting a wide range of applications including in Bordeaux mix, fire blight, leaf 

curl, downy mildew, powdery mildew, peacock spot, walnut blight, etc. Certifiers listed low levels of 

users in Organic System Plans (OSPs) in some regions of the country, but listed numerous uses in regions 

with a higher density of orchards and vineyards. A stakeholder also noted that hydrated lime does not 

demonstrate phytotoxicity on either leaves or fruit.

The Crops Subcommittee discussed the potential for environmental issues especially in regard to aquatic 

environments. The TR notes that there is very little chance of contamination and the CS expressed 

comfort with continuing to list this material.

Justification for Vote:

The NOSB finds hydrated lime compliant with the Organic Foods Production Act (OFPA) and/or 7 

CFR205.600 and is not proposing removal.

NOSB Vote::

Motion to remove hydrated lime from the National List

Motion by: Mindee Jeffery

Seconded by: Amy Bruch

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2 

Motion failed

Liquid fish products

Reference: 205.601(j) As plant or soil amendments. 

(8) Liquid fish products - can be pH adjusted with sulfuric, citric or phosphoric acid. The amount of acid 

used shall not exceed the minimum needed to lower the pH to 3.5.

Technical Report: 1995 TAP; 2006 TR (fish-based fertilizers); 2019 TR (liquid fish products)

Petition(s): N/A
Past NOSB Actions: 04/1995 NOSB minutes and vote (pg. 346); 11/2005 NOSB sunset recommendation; 

10/2010 NOSB sunset recommendation; 10/2015 NOSB sunset recommendation; 10/2018 NOSB sunset 

recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Sunset renewal 

notice published 10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); 

Sunset renewal notice published 03/15/2017 (82 FR 14420); Sunset renewal notice published 

05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

Liquid fish products are used as fertilizers in the production of organic crops. Liquid fish products contain 

fundamental nutrients and many trace minerals critical for use in organic farming. Liquid fish foliar 

application can deliver important nutrients that can reduce certain nutrient stresses which can, in turn, 

improve crop yields.

Manufacture:

Liquid fish products are fish hydrolysates that are made from chopped fish byproducts that are (1) 

enzymatically digested and heated, or (2) enzymatically processed without heat (cold processing). Liquid 

fish products are then stabilized with an acid, such as phosphoric, sulfuric, or citric acid, to prevent 

microbial growth. The use of formic acid is prohibited due to phytotoxicity. A third method of liquid fish 

product manufacture utilizes fermentation by bacteria that produce lactic acid, which preserves the fish. 

All three methods of liquid fish product manufacture cannot result in a pH below 3.5.

International Acceptance:

Canadian General Standards Board Permitted Substances List

The Canadian Organic Standard allows for the use of liquid fish products. Acids are permitted to lower 

the pH to 3.5, but no prohibited preservatives can be used. 

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Liquid fish is not on the EU Annex I list of approved fertilizers, but the EU does allow fish meals.

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

Contingent upon recognition from a certification body or authority. 

International Federation of Organic Agriculture Movements (IFOAM)

The International Federation of Organic Agriculture Movements (IFOAM) permits using fish and shell 

products and food processing of animal origin. 

Japan Agricultural Standard (JAS) for Organic Production

The Japanese Organic Standard permits the use of food industry byproducts of fish origin if they are 

derived from natural sources.
Environmental Issues:

Nutrient runoff from excessively or improperly applied fertilizers can cause eutrophication of surface 

waters, potentially harming fish, and other aquatic animals.

Global impacts of commercial fisheries on marine ecosystems include documented fish population 

decline (and in some cases, ecosystem collapse) due to overharvesting. Liquid fish products are derived 

from several sources, including fish waste and bycatch/mortalities. To a lesser extent, fish are harvested 

for meal, oil, and solubles (also known as the wet reduction process). Large-scale population declines 

have occurred, with at least three fish species harvested for meal, oil, and soluble production. 

Considering this information, during the previous sunset review, conducted in 2018, the Crops 

Subcommittee added a work agenda item regarding liquid fish products. At the October 2020 meeting, 

the Board proposed, approved, and recommended to the NOP to add an annotation to liquid fish 

products at § 205.601(j)(8) to limit the use to fish sourced from waste left over aftermarket food fish are 

processed for human consumption, bycatch, and invasive species.

Discussion:

Previous NOSB sunset review summary: Historically, there has been strong support for keeping liquid 

fish products on the National List, and public comment at the October 2018 NOSB meeting reiterated 

the strength of that support. Farmers consider liquid fish products essential for many crops, including 

foliar and other applications. Concerns about the sustainability of source fish, including the possible use 

of wild fish harvested for the sole purpose of producing liquid fertilizers, were raised by the Crops

Subcommittee, and extensive discussion during the October 2018 NOSB meeting focused on production 

methods and sources of raw fish material for the production of fish-based fertilizers. These discussions 

resulted in a work-agenda request to assess the environmental impact of harvesting wild, native fish for 

all fertilizer purposes, to protect natural fish populations, and to ensure that liquid fish and other fishbased fertilizer products used in organic production are not harmful to the environment. Information 

from this review could inform future policy recommendations regarding the use of wild fish for organic 

fertilizers but is beyond the scope of review for this sunset review.

The current Crops Subcommittee discussed the uses of liquid fish products as a plant or soil 

amendment, the manufacturing process, and environmental issues. The Subcommittee also reviewed 

the October 2020 NOSB recommendation on Wild, Native Fish for Liquid Fish Products, which the NOP 

has not implemented; it is currently listed as “Closed” in the NOSB Recommendations Library.

Spring 2023 Sunset Review: The NOSB reviewed liquid fish products, and Board members and 

commenters supported relisting, as liquid fish products deliver needed nutrients to a wide variety of 

crops and growing environments. Two commenters requested more rigor with the annotations to 

reduce environmental impact. The community also expressed support for the 2020 NOSB 

Recommendation on Wild Native Fish and called for its implementation. The 2020 recommendation 

limits liquid fish products to be made with fish “sourced only from fish waste, bycatch, or invasive 

species.” The NOP stated at the Spring 2023 meeting that the recommendation regarding the 

annotation was currently on hold. 

The Subcommittee continued discussing the importance of the annotation and reviewed the history of 

previous marine material votes, including the fish oil annotation (handling) from the Fall 2021 NOSB 

meeting, which included the reliance on a third-party certification until organic aquaculture standards 

are approved. The Subcommittee also reviewed the 2016 NOSB recommendation to add squid 

byproducts to the National List with the rationale that “the addition of squid byproducts is consistent 

with the National List listing for liquid fish products that are pH adjusted with synthetic sulfuric, citric or 
phosphoric acid (7 CFR 205.601(j)(7)). Only squid byproducts originating from the food processing waste 

stream are acceptable for use in organic agriculture. Whole squid caught for fertilizer purposes would 

not be included in this listing”. Since there seems to be a precedent for the term byproducts (similar to 

bycatch) being accepted, the Subcommittee was hopeful that the liquid fish annotation from 2020 could 

eventually be completed. 

The NOSB Recommendations Library lists the recommendation for Wild, Native Fish for Liquid Fish 

Products, as closed, and the reason stated is “technical complexity of marine environments makes 

rulemaking on these topics problematic. NOP does not currently plan to move this item forward”.

Commenters also expressed concerns that even if fish do not have commercial value they may have 

ecological value. Commenters also noted that use of discarded fish parts for fertilizer may remove food 

from marine ecosystems; there’ a potential for contamination with PFAS, and more restrictive 

annotations could be added to reduce environmental impact. The Board also considered that farming 

practices need to be leveraged when applying liquid fish products. 

Lastly, one commenter noted concerns about the potential of fortification with phosphorus. The Board 

will review further information regarding the essentiality of phosphorus versus the other acids allowed 

for use to adjust pH listed in the annotation. 

At the Fall 2023 NOSB meeting, the Board reviewed the history of the previous NOSB recommendation 

to annotate liquid fish products. The information is detailed in this proposal as well. There were strong 

feelings from the Board and the community to find a pathway forward for the annotation, however, the 

NOP noted that it would not proceed with rulemaking on the annotation request, leaving the material 

listed as is. Since the product was determined to be essential by many farmers and groups representing 

farmers, the Board voted to maintain the listing. 

Justification for Vote: 

The NOSB finds liquid fish products compliant with the Organic Foods Production Act (OFPA) and/or 7 

CFR 205.600 and is not proposing removal.

NOSB Vote: 

Motion to remove liquid fish products from the National List

Motion by: Amy Bruch

Seconded by: Mindee Jeffery

Yes: 1 No: 11 Abstain: 1 Recuse: 0 Absent: 2

Motion failed

Sulfurous acid

Reference: 205.601(j) As plant or soil amendments. 

(11) Sulfurous acid (CAS # 7782-99-2) for on-farm generation of substance utilizing 99% purity elemental 

sulfur per paragraph (j)(2) of this section.

Technical Report: 2010 TR; 2014 TR; 2023 Limited Scope TR

Petition(s): 2008
Past NOSB Actions: 05/2009 NOSB recommendation; 10/2014 NOSB sunset recommendation; 10/2018 

NOSB sunset recommendation

Regulatory Background: Added to National List 07/07/2010 (75 FR 38693); Sunset renewal notice 

published 06/19/2015 (80 FR 35177); Sunset renewal notice published 05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

The primary use of sulfurous acid is as an acidifying agent to neutralize and reduce excessive alkalinity in 

soil and/or water. The resulting acidic irrigation water can be helpful with nutrient deficiencies that arise 

when saline or alkaline conditions tie up essential micronutrients. This use supports improved crop 

yields and can help to reduce soil degradation from salinity build up.

Manufacture:

The primary ingredients used in the preparation of sulfurous acid are water and elemental sulfur. 

Almost all elemental sulfur is produced as a byproduct of coal, natural gas, and petroleum refinement. 

Sulfurous acid is manufactured by spraying water through smoke and fumes created by burning 

elemental sulfur. Several substances are created in this process, including sulfur dioxide, hydrogen 

sulfide, and hydrogen sulfite.

International Acceptance:

Canadian General Standards Board Permitted Substances List

Sulfurous acid can be used in the production of Canadian Organic Products as a preservative in alcoholic 

beverages made from grapes or other fruit, although minimum use is recommended. No mention is 

made of sulfurous acid as a soil amendment (CGSB, 2011a,b).

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Sulfurous acid is allowed in wine production only.

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

Sulfurous acid is allowed in wine production only.

International Federation of Organic Agriculture Movements (IFOAM)

Sulfurous acid is allowed by IFOAM in wine production, as a pH adjuster in sugar production, and is a 

permitted soil amendment.

Japan Agricultural Standard (JAS) for Organic Production

JAS does not mention sulfurous acid but allows sulfuric acid as a pH adjuster in sugar production.

Environmental Issues:

Sulfurous acid appears on the EPA non-food inert list and does not require a tolerance or an exemption 

from tolerance. According to a sulfurous acid manufacturer (and noted in the 2014 TR, lines 229-232) 

sulfur dioxide released into the atmosphere by a sulfurous acid generator is minimal. The EPA does not 

regulate this emission. Sulfurous acid contains no persistent substances of record. Hydrogen sulfite 

present in the solution is metabolized by sulfite-reducing bacteria and plants that recycle sulfurous acid 
into bioavailable sulfur compounds. Water and other dissolved compounds leach into the soils. 

Functionally sulfurous acid serves to condition soils by adjusting pH.

Regarding human health concerns and per the 2014 TR, sulfurous acid is not expected to be carcinogenic 

(2014 TR, lines 370-371). Sulfur dioxide is approved by the US Food and Drug administration for use as a 

food preservative and food colorant (2014 TR, lines 371-372).

Discussion:

During the Fall 2018 meeting, the NOSB voted unanimously to keep sulfurous acid on the National List. 

Most of the written comments at the Fall 2018 meeting supported the relisting, several indicated “no 

reported use” and one commented that no synthetic fertilizers should be permitted.

The NOSB discussed this listing at its Spring 2023 meeting with some members referencing stakeholder 

comments, which declared sulfurous acid highly essential in the Pacific Northwest. The Board also noted 

that sulfurous acid has broader base applications as it removes contaminants as well as adjusts pH.

A limited scope TR was received by the Crops Subcommittee in early February 2023 and was declared 

sufficient during the Subcommittee meeting held on February 9th, 2023. The TR authors did a seemingly 

complete job of listing potential alternatives and then evaluating these alternatives as being less 

effective than sulfurous acid. 

For the 2023 Fall session the NOSB received about 14 stakeholder comments, mostly all in written form. 

Nearly all were supportive of continued use of sulfurous acid. One stakeholder group expressed concern 

that the use of sulfurous acid could potentially mask poor soil conditions and/or practices.

Justification for Vote:

The NOSB finds sulfurous acid compliant with the Organic Foods Production Act (OFPA) and/or 7 CFR 

205.600 and is not proposing removal.

NOSB Vote:

Motion to remove sulfurous acid from the National List

Motion by: Jerry D’Amore

Seconded by: Brian Caldwell

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed

Ethylene gas

Reference: 205.601(k) As plant growth regulators. 

(1) Ethylene gas—for regulation of pineapple flowering.

Technical Report: 1999 TAP; 1999 TAP (handling) (pg. 14-54); 2000 TAP (supplemental information); 

2007 TAP; 2011 Limited Scope TR; 2023 TR (crops, handling)

Petition(s): N/A
Past NOSB Actions: 10/1999 NOSB recommendation (handling) (pg. 443); 10/2001 recommendation 

(handling) (pg. 2); 11/2005 NOSB sunset recommendation; 04/2011 NOSB sunset recommendation; 

10/2015 NOSB sunset recommendation; 10/2018 NOSB sunset recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Technical 

correction annotation change published 10/31/2003 (68 FR 61987); Sunset renewal notice published 

10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); Sunset renewal 

notice published and was effective 03/15/2017 (82 FR 14420); Sunset renewal notice published 

05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

Ethylene gas is on the National List for use as a plant growth regulator, for organic pineapple production 

only. Ethylene gas is used to induce uniform flowering in pineapples and is applied 7-15 months after 

planting. Application can be repeated two to three times after the initial application (2011 TR 53-56). 

Ethylene gas is made from hydrocarbon feedstocks, such as natural gas liquids or crude oil. Operators 

should be well trained and prepared. However, the safety concern to workers is limited when correctly 

used and monitored (2007 TAP, pg. 4).

Manufacture:

The principal source of commercial ethylene is from thermal or catalytic cracking of hydrocarbon 

feedstocks such as natural gas or crude oil. During this process chemical bonds within the hydrocarbon 

molecules are broken, and a different chemical substance is produced.

Ethylene is the petrochemical produced in the largest quantities worldwide (IARC, 1994). In 2014, world 

ethylene production was 134 million (metric) tonnes (Lazonby, 2017). As of 1994, over 95% of 

worldwide annual production is based on thermal “cracking” of petroleum hydrocarbons with steam 

(IARC, 1994). These fractions are obtained from drilling (or hydrofracturing) of oil or natural gas. 

Thermal cracking (sometimes referred to as pyrolysis) is a chemical process by which long chain 

hydrocarbons with higher molecular masses are converted to short chain hydrocarbons of lower 

molecular mass [2023 TR 304-309].

All of these methods involve reactions that produce a chemically changed substance (ethylene) from 

either petroleum feedstocks, or from dehydration of ethanol mediated by catalysts. Thus, all these 

forms should be considered synthetic (NOP, 2016a) and from nonagricultural sources (NOP, 2016b). 

[2023 TR 369-371]

Various feedstocks, including ethane, propane, butanes, naphthas, and gas oils are used to produce 

ethylene, depending on availability, price, and products desired (Lazonby, 2017). Naphthas are the 

principal raw material used in western Europe and Japan, accounting for over 80% of the ethylene 

produced. Ethane is the primary feedstock in the U.S., followed by propane, naphthas, gas oils, and 

butane (Zimmerman & Waltz, 2011) [2022 TR 311-315]. 

 

In thermal cracking, the feedstock gases (ethane, propane or butane) or the liquids (naphtha or gas-oil) 

are preheated and vaporized, and are mixed with steam and heated to 1050-1150 K (777-877 °C) in a 
tubular reactor. The high temperature and pressure cause the long chain hydrocarbon to be converted 

to low relative molecular mass alkenes plus by-products (Lazonby, 2014). [2022 TR 317-320]

Catalytic cracking

Catalytic cracking uses a catalyst, typically a zeolite, which adsorbs the long-chain hydrocarbon 

feedstocks and removes hydrogen atoms. [1] This causes the long chains to split into shorter chain 

molecules with double bonds, which are useful to the petrochemical industry. The feedstock is gas oil, 

which is vaporized, passed through a fine zeolite powder, and heated to 700-800 K (427 - 527 °C) in a 

reactor. The products behave like a fluid and continuously flow out of the furnace with the cracking 

products. The temperature, residence time, and the catalyst determine the product proportions 

(Lazonby, 2014) [2022 TR 332-338].

 

Dehydration of ethanol

Dehydration of ethanol is another commercial route to ethylene (IARC, 1994; Zimmerman & Waltz, 

2011; Fan 2013). In the catalytic dehydration of ethanol to form ethylene, an acid catalyst first 

protonates the hydroxyl group, which leaves as a water molecule. The conjugate base of the catalyst 

then deprotonates the methyl group, and the hydrocarbon rearranges into ethylene (Fan, 2013). This 

method is not commonly used to produce large volumes of ethylene, as it is endothermic with a high 

optimal reaction temperature (180-500 °C), which makes the ethylene expensive to produce. 

Dehydration of bioethanol is occurring in Brazil and India and holds promise for producing ethylene from 

non-fossil fuel sources (bioethanol from sugar cane or cellulose). At present, the output is relatively 

limited and used for further production of polyethylene (Fan, 2013; Lazonby, 2017; Schill, 2010) [2022 

TR 340-349].

 

Catalytic generators

Small catalytic generators are used in sealed ripening rooms to dehydrate ethanol into ethylene, and can 

deliver controlled levels of ethylene gas to ripen fruit, e.g., 100-150 ppm for bananas. (NWHort 2008, 

Catalytic Generators 2022). This process uses dehydration of ethanol by passing it over a bed of solid 

catalyst held at high temperatures. The catalysts are typically activated alumina and phosphoric acid or 

zinc oxide with alumina (Kays & Beaudry, 1987) [TR 351-356].

International Acceptance:

Canadian General Standards Board Permitted Substances List

Allowed for use in Canadian organic production for post-harvest ripening of tropical fruit and degreening of citrus and to control sprouting of potatoes post-harvest in holding bins.

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Allowed for use in Europe organic production in the degreening of bananas, kiwis, and kakis; Degreening 

of citrus fruit only as part of a strategy for preventing fruit fly damage in citrus; Flower induction of 

pineapple; sprouting inhibition in potatoes and onions.

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

CODEX indicates:

“For degreening of citrus for fruit fly prevention and as a flowering agent for pineapples. As sprouting 

inhibitor for potatoes and onions: Need recognized by the certification body or authority for sprout 

inhibition of stored potatoes and onions where varieties that have long dormancy characteristics are not 
available, or these varieties are not suited to local growing conditions. Must be used in a manner that 

minimizes exposure to operators and workers.” 

International Federation of Organic Agriculture Movements (IFOAM)

Ethylene gas is allowed in organic production by IFOAM for the de-greening and ripening of citrus.

Japan Agricultural Standard (JAS) for Organic Production

JAS limits the allowed use of ethylene gas to the ripening of bananas, kiwifruits, and avocados after 

harvest.

Environmental Issues:

According to the 2023 TR, the manufacturing process through cracking is highly energy intensive. 

Extraction and transport contribute significantly to increasing greenhouse gas emissions, acidification 

and eco-toxicity (air and water). [TR 479-482] 

Petroleum refineries are a major source of hazardous and toxic air pollutants. In the TR, manufacture of 

ethylene does produce “significant” amounts of carbon dioxide, and notes that this may be a factor in 

development of alternative technologies for production of ethylene. Ethylene, one of the most 

important chemicals in use, consumes 30% of the total energy of the chemical industry. This study found 

that China reduced CO2 emissions by 29.4% per ton of ethylene produced from 2000-2016 due to 

improvements in technology and evaluated various methods for future increased reductions (2022 TR 

488-495). 

As for ethylene’s impact on the environment during postharvest handling, the 2023 TR states that since 

the ethylene is a gas at environmental temperatures, this is the primary route of exposure to the 

environment. Health Canada considered environmental modelling studies and found that ethylene 

released to the air will remain in the air, and that only negligible amounts will partition to soil, water and 

sediment [TR 507-511]. The same study concluded that there is little risk of harm to the environment or 

to organisms since the substance is not present in quantities or concentrations that could cause long 

term harmful effects on the environment or biodiversity. [2023 TR 531-536]

If every acre in pineapple production (organic and conventional) was treated with high application rates, 

it would be 5% of the total ethylene emissions (2023 TR lines 513-521). No new issues of human health 

or environmental concerns were raised that had not been addressed in previous NOSB Sunset review 

cycles. The main safety concern in relation to ethylene use has been the explosive nature of the gas in 

the air. Operators should be well trained and prepared, though the safety concern to workers is low 

when correctly used and monitored (2007 TAP, pg. 4). Ethylene is not considered a food ingredient, and 

is not regulated by FDA. It is exempt from residue tolerances established by EPA when used as a 

postharvest plant growth regulator on food crops (2023 TR lines 455-457).

Discussion:

The Crops Subcommittee discussed the use, manufacturing, and environmental issues, and previous 

NOSB reviews of ethylene gas. 

As part of the Spring 2018 public meeting, the Crops Subcommittee requested additional information 

regarding the issue of scale and the use of ethylene and alternative technologies. Written and oral 

commenters expressed continued support for this material.

 
At the Spring 2023 public meeting, the Crops Subcommittee requested additional information on the 

need for expanding the use of this material and if there were any alternatives. Again, written and oral 

commenters expressed continued support for this material, stating that it is an essential tool for the 

commercial production of pineapples for the export market and no viable alternatives exist. Without 

ethylene, commenters said, it would be impossible to achieve the uniform ripening necessary for timing 

the harvest for fruit shipment. There were 13 commenters that supported the relisting of this material 

with only one in opposition, stating that the material does not fit any OPFA criteria, and it is not 

essential to produce the crop but rather is employed for economic reasons. One member of the 

Subcommittee expressed concern about the use of this material to produce the crop during unfavorable 

growing times, which results in poor quality fruit. 

 

Fall 2023 public comments predominantly supported the relisting of this material, stating that it was 

necessary for small-and-large-scale pineapple growers. The NOSB discussion questioned the use and if it 

affected the quality of fruits, implying that the use of this material induced maturity when it was not 

environmentally conducive. One written commenter explained that the material was not used to affect 

maturity, only the timing of the onset of flowering. 

Justification for Vote: 

The NOSB finds ethylene gas compliant with the Organic Foods Production Act (OFPA) and/or 7 CFR 

205.600 and is not proposing removal.

 

NOSB Vote: 

Motion to remove ethylene gas from the National List

Motion by: Logan Petrey

Seconded by: Jerry D’Amore

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed

Microcrystalline cheesewax

Reference: 205.601(o) As production aids. 

(1) Microcrystalline cheesewax (CAS #'s 64742-42-3, 8009-03-08, and 8002-74-2)-for use in log grown 

mushroom production. Must be made without either ethylene-propylene co-polymer or synthetic 

colors.

Technical Report: 2018 TR

Petition(s): 2007; 2008 (Addendum #1)

Past NOSB Actions: 05/2008 NOSB recommendation; 10/2015 NOSB sunset recommendation; 10/2018 

NOSB sunset recommendation

Regulatory Background: Added to National List 03/15/2012 (77 FR 8089); Sunset renewal notice 

published 03/15/2017 (82 FR 14420); Sunset renewal notice published 05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025
NOSB Review:

Use:

Microcrystalline cheesewax has been used in agriculture as a production aid in log-grown shiitake 

mushrooms since the 1980s, and has been allowed in organic agriculture since 2012. Microcrystalline 

cheesewax is used to seal holes in hardwood logs (commonly oak) after the shiitake spawn is inserted.

Manufacture:

Microcrystalline cheesewax is a food-grade product made up of a mixture of microcrystalline wax, 

paraffin wax, and petroleum. All three of these materials come from refining crude oil, where these 

petroleum waxes are separated by fractional distillation followed by fractional crystallization.

International Acceptance:

Canadian General Standards Board Permitted Substances List 

CAN/CGSB-32.311 “Table 6.5 Processing aids” prohibits microcrystalline wax “either alone or in 

formulation with paraffin wax.”

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Neither microcrystalline cheesewax, nor its components, are listed in EC No. 834-2007 nor EC 

No.889/2008.

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

Neither microcrystalline cheesewax, nor its components, are listed in the CODEX (GL 32-1999).

International Federation of Organic Agriculture Movements (IFOAM)

Neither microcrystalline cheesewax, nor its components are listed in IFOAM.

Japan Agricultural Standard (JAS) for Organic Production

Neither microcrystalline cheesewax, nor its components, are listed in the JAS for organic food 

production.

Environmental Issues (and human health concerns):

Per the 2018 TR and referenced studies: “There have been no reports that indicate the likelihood of the 

bioaccumulation of either microcrystalline cheesewax or its breakdown products, nor any reports of 

associated ecotoxicity.” Microcrystalline cheesewax is widely regarded as “readily biodegradable” [232-

239]. 

Also, per the 2018 TR, “...microcrystalline cheesewax, its components, and its breakdown products are 

chemically stable and are not known to be health risks.” [308-309]. Microcrystalline cheesewax is 

sometimes heated just before being used as a sealant, at which time caution should be used to avoid 

inhaling the vapor as this could cause respiratory irritation [317].

Discussion:

At the Fall 2018 meeting, the NOSB voted unanimously to keep microcrystalline cheesewax on the 

National List. Some of the written comments reviewed during the Fall 2018 meeting focused on the 

current need for microcrystalline cheesewax, saying that the production method (inoculated logs) was 

no longer used. This notion was countered by the assertion that there was still wide use by small 

growers. 
During the April 2023 NOSB meeting this same question of continued use was discussed and reaffirmed 

as essential for small growers. 

The Fall 2023 stakeholder comments mirrored the Spring comments almost exactly giving further 

support to this material’s essentiality within the community of small growers.

Justification for Vote:

The NOSB finds microcrystalline cheesewax compliant with the Organic Foods Production Act (OFPA) 

and/or 7 CFR205.601(o) and is not proposing removal.

NOSB Vote: 

Motion to remove microcrystalline cheesewax from the National List

Motion by: Jerry D’Amore

Seconded by: Brian Caldwell

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed

Potassium chloride

Reference: 205.602(e) Potassium chloride—unless derived from a mined source and applied in a 

manner that minimizes chloride accumulation in the soil.

Technical Report: 1995 TAP; 2023 TR

Petition(s): N/A

Past NOSB Actions: 11/1995 NOSB minutes and vote (pg. 22); 11/2005 NOSB sunset recommendation; 

10/2010 NOSB sunset recommendation; 10/2015 NOSB sunset recommendation; 10/2018 NOSB sunset 

recommendation

Regulatory Background: Added to National List 04/21/2001 (65 FR 80547, 66 FR 15619); Sunset renewal 

notice published 10/16/2007 (72 FR 58469); Sunset renewal notice published 06/06/2012 (77 FR 33290); 

Sunset renewal notice published 03/15/2017 (82 FR 14420); Sunset renewal notice published 

05/07/2020 (85 FR 27105)

Sunset Date: 6/22/2025

NOSB Review:

Use:

Potassium is required for health in humans, plants, and microorganisms (1995 TAP pg. 4, 14). Potassium 

is an essential element for plants as they use it to regulate movement of water and nutrients within the 

plant, photosynthesis regulation, and enzyme activation. While potassium is found in many soils, it may 

not exist naturally in a high enough concentration for optimal plant growth, and/or it may be present 

but in a bound format rendering it unavailable. Potassium is commonly used by growers either alone, as 

a complex in potassium chloride, or as an ingredient in a fertilizer blend for soil supplementation. 

Chloride is also an essential element for plants (TAP pg. 12); however, monitoring of chloride use is 

required to assure soil salinity is managed appropriately. The current annotation in the USDA organic 
regulations stipulates chloride monitoring when potassium chloride is used to prevent chloride 

accumulation in soils.

Manufacture:

Potassium chloride is a mineral that occurs naturally and is a product of potash mining where water is 

forced into the ground to dissolve potassium chloride deposits (1995 TAP, pg. 3). Brine is brought back 

to the surface where the water is evaporated off to isolate the potassium chloride. Potassium chloride 

can similarly be produced from sea water extraction via solar evaporation.

International Acceptance:

Canadian General Standards Board Permitted Substances List

Permitted for use from mined sources such as sylvite, carnalite, and potash.

European Economic Community (EEC) Council Regulation, EC No. 834/2007 and 889/2008

Not specified as permitted for use.

CODEX Alimentarius Commission, Guidelines for the Production, Processing, Labelling and Marketing of 

Organically Produced Foods (GL 32-1999)

Permitted for use.

International Federation of Organic Agriculture Movements (IFOAM)

Permitted for use.

Japan Agricultural Standard (JAS) for Organic Production

Permitted as “fertilizers and soil improvement substances.”

Environmental Issues:

Potassium chloride is derived from energy-intensive mining activities, and there are impacts associated 

with its extraction and the processing wastes that can be generated. While heavy metals have been 

known to concentrate near potassium chloride production, there has not been widespread concern 

about significant impacts.

Discussion:

At the Fall 2018 meeting, the NOSB unanimously voted to relist potassium chloride at 7 CFR 205.602.

During 2018 meetings, public commenters were also unanimously supportive of continued listing with 

the current annotation, and there were no other non-chloride types reported by the public. At the time, 

one certifier recommended that the NOSB request a technical report (TR) on potassium chloride to 

thoroughly consider the use of synthetic dust suppressants or other synthetic additives.

A draft TR was provided to the Crops Subcommittee on December 2, 2022 and was deemed sufficient, 

although the Subcommittee requested additional information on effective organic alternatives to 

potassium chloride. This 2023 TR was pending at the time of deadlines for the Spring 2023 meeting and 

received by the board thereafter. The technical report is helpful in reiterating the importance of 

potassium in crop nutrition and outlines ongoing research for recent years into the complex relationship 

between potassium, plant tissue, and the environment, particularly with respect to plant resilience and 

stress response. Similarly, the report describes ongoing challenges in understanding the relationship 

between potassium and nitrogen in crop growth. It also discusses the tension between chlorine 
deficiency and excess chlorine in plants. Chloride ions are quite soluble and not easily absorbed by 

organic matter or clay in soils, hence the requirement to closely monitor chlorine accumulation that 

could result in the application of the listed substance (the TR offers some critique of the high end of the 

range of rates of application of the substance sometimes recommended by agronomists). The main 

concern with overapplication of potassium chloride is its contribution to soil and groundwater salinity 

(and the highest salt index of any common dry fertilizer), but little data could be present to suggest its 

toxicity to fauna. The TR did allude to the energy intensiveness of the production of potassium chloride 

and the associated contribution that production can have to atmospheric carbon concentrations and 

climate change.

The Crops Subcommittee has had anecdotal discussions about whether or not potassium chloride (per 

this listing) is being used by organic growers. Subcommittee members have acknowledged that 

potassium chloride is an inexpensive means of dealing with potassium deficiencies in the soil and is 

likely very geographically specific in its application (potassium is prevalent in high mineral soils, for 

example, and thus minimal need for supplemental potassium), but also noted that potassium sulfate 

may be another good cost-effective alternative with less adverse effect. Subcommittee members also 

discussed the nature of the annotated listing itself and whether it has been successful in reducing 

chloride leaching – and associated environmental impact -- where it is applied, and also noted that if 

chloride buildup in the soil is an issue that merits monitoring, there are likely other problematic 

accumulations in the soil in such contexts as well. The Crops Subcommittee discussed the wide use of 

potassium chloride in conventional agriculture and the fact that conventional growers are able to 

mitigate salt concerns by virtue of the conventional toolkit.

The full Board discussed this listing at its Spring 2023 meeting in the wake of strong continued support 

from the community for the listing to continue in its current incarnation. Board members noted that 

potassium chloride is used by some organic producers as a less expensive potassium source and without 

creating the chloride accumulation that was the primary concern from the annotation on this listing. 

Members also discussed the use of potassium sulfate as an alternative to potassium chloride and 

acknowledged the lower potassium levels in potassium sulfate and the substance’s potential for soil 

acidification.

The Subcommittee discussed monitoring guidelines for chloride concentration.

Questions to our Stakeholders

1. Is potassium chloride widely used by producers of organic crops?

2. What is the process at certification for monitoring chloride concentration when this substance is 

listed for use on an organic system plan?

In 2023 public comments were unanimous in support of maintaining the restriction on the use of 

potassium chloride in organic crop production, although some certifiers have indicated that the material 

does appear (with this restriction) in numerous OSPs and has grown in use over time. Some commenters

urged caution in the context of this listing to ensure that consistency is applied across crop types and 

certifiers around monitoring for chloride accumulation in soil. The NOSB had limited discussion and was 

supportive of maintaining this restricted listing.

Justification for Vote:

The NOSB finds this listing of potassium chloride compliant with the Organic Foods Production Act 

(OFPA) and/or 7 CFR 205.600 and is not proposing removal.
NOSB Vote:

Motion to remove potassium chloride from the National List at 7 CFR 205.602(e)

Motion by: Wood Turner

Seconded by: Mindee Jeffery

Yes: 0 No: 13 Abstain: 0 Recuse: 0 Absent: 2

Motion failed