Formal Recommendation 

From: National Organic Standards Board (NOSB)

To: the National Organic Program (NOP)

Date: April 27, 2016

Subject: Addition of Hypochlorous Acid generated from electrolyzed water, as petitioned, 

at §205.601(a) of the National List.

NOSB Chair: Tracy Favre

The NOSB hereby recommends to the NOP the following: 

Rulemaking Action: X

Guidance Statement:

Other:

Statement of the Recommendation: 

That hypochlorous acid be classified as synthetic, and that hypochlorous acid be listed as petitioned at

§205.601, Synthetic substances allowed for use in organic crop production, (a) as algicide, disinfectants, 

and sanitizer, including irrigation system cleaning systems. (2)Chlorine materials (iv) Hypochlorous acid 

generated from electrolyzed water. 

There were some concerns raised during public comment regarding the source, so the Board voted to add 

the annotation: “generated from electrolyzed water”. The petition, Subcommittee review, and technical 

review were all for hypochlorous acid generated via electrolyzed water. The annotation clarifies that the 

source is limited to generation from electrolyzed water, as petitioned. 

Rationale Supporting Recommendation:

The substance was found to be consistent with OFPA criteria. Hypochlorous acid is present in solutions of 

two chlorine sanitizers (sodium hypochlorite and calcium hypochlorite) currently allowed at 

§205.601(a)(2)(i, ii). As formulated via electrolyzed water, hypochlorous acid is effective as a sanitizer at a 

much lower chlorine concentration and is safer for health and the environment than the currently listed 

chlorine sanitizers. This material better aligns with the fundamental principles of organic crop production 

than many of the alternative materials currently allowed.

NOSB Vote: 

Classification Motion: Move to classify hypochlorous acid as synthetic.

Motion by: Harold V. Austin IV 

Seconded by: Francis Thicke

Yes: 15 No: 0 Abstain: 0 Absent: 0 Recuse: 0

Listing Motion: Move to list hypochlorous acid generated from electrolyzed water, as petitioned, at 

§205.601(a) As algicide, disinfectants, and sanitizer including irrigation system cleaning systems. (2)

Chlorine materials (iv) Hypochlorous acid generated from electrolyzed water.

Motion by: Harold V. Austin IV 

Seconded by: Emily Oakley

Yes: 15 No: 0 Abstain: 0 Absent: 0 Recuse: 0 

Motion Passed 
National Organic Standards Board

Crop Subcommittee

Petitioned Material Proposal - Hypochlorous Acid

February 16, 2016

Summary of Proposed Action:

On May 29, 2015 the NOP received a petition to add Hypochlorous Acid (CAS #7790-92-3) to the National 

List at §205.601 - Synthetic substances allowed for use in organic crop production. This material is being 

petitioned for use as an antimicrobial/sanitizer for use on equipment and raw agricultural products. The 

petition was forwarded to the Handling Subcommittee on June 3, 2015 and later that summer the Crops 

Subcommittee was asked to review this material as well, since there are multiple listings being requested 

by the petitioner. The Livestock Subcommittee is also reviewing hypochlorous acid.

The petition was submitted by Botanical Food Company Pty Ltd. Hypochlorous acid (electrolyzed water) is 

being petitioned for use in organic crop production for a couple of different uses, including: a) as a postharvest sanitizer for raw herb and spice materials ˂60ppm and b) as an equipment and cold room sanitizer 

˂200ppm. 

This petition has been submitted in response to a policy memo issued by the NOP on June 9, 2014: PM 14-3 

Electrolyzed Water. The memo was issued as a response to requests asking for the National Organic 

Program to clarify whether electrolyzed water (EW) was allowed as a sanitizer and antimicrobial agent for 

use in organic production and handling.

The NOP felt that the allowance of EW by a certifier or a material evaluation program were based on an 

incorrect interpretation of the allowance for chlorine materials on the National List of Allowed and 

Prohibited Substances at 7CFR §205.600-606. The NOP requested that certifiers ensure that the use of EW 

was not allowed in organic handling or production and that any party wishing for further consideration of 

EW for use in organic handling or production, should then submit a petition to get it added to the National 

List. Thus, the rationale for the petition currently before the Crops subcommittee and the full NOSB is in 

response to the NOP policy memo.

Manufacture and Uses of the Substance:

Electrolyzed water (EW) is the product of the electrolysis of a dilute sodium chloride solution in an 

electrolysis cell containing a semi-permeable membrane that physically separates the anode and cathode, 

but permits ions to pass through. In the process, hypochlorous acid, hypochlorite ion, and hydrochlorite 

acid are formed at the anode, and sodium hydroxide is formed at the cathode. The solution formed on the 

anode side is acidic EW (pH 2 to 6), and the solution formed on the cathode side is basic EW (pH 7.5 to 13). 

Neutral EW, with a pH of 6 to 7.5 is produced by mixing the anodic solution with hydroxide, or by using a 

single-cell chamber for electrolysis. (TR lines 48-68).

The effectiveness of hypochlorous acid as an active sanitizing agent is determined in large part by the 

solution pH. Hypochlorous acid exists interchangeably with other chlorine species, including chlorine, 

hydrogen chloride (aqueous and gaseous) and hypochlorite. In a controlled pH environment hypochlorous 

acid will exist as the dominant chlorine species under pH conditions ranging from 2 to 7. (TR lines 84-89).

EW has received recent attention as an alternative to other chlorine disinfectants and sanitizers. A number 

of studies have demonstrated the strong antibacterial activity of EW against foodborne pathogens on raw 

agricultural products. Similar studies and actual in field use (and facility use) has demonstrated similar 

activity when used to sanitize equipment and storage facilities. This material was (prior to the USDA/NOP 

memo PM 14-3 Electrolyzed Water) previously approved by at least one material review organization and 

multiple certifiers for use on crops and allowed for uses other than what is currently being petitioned. Prior 
to the NOP memo it was also beginning to be used for control of powdery mildew in apples and to aid in 

prevention of other pathogens or microbial contamination on fresh fruits and vegetables (leafy lettuce) that 

might pose a risk to human health.

According to the Hypochlorous Acid TR (August 13, 2015) it states that some of the advantages of using EW 

are: 1) EW is as effective as any chlorine treatment, 2) it is not necessary to handle potentially dangerous 

chemicals, e.g. chlorine gas, chlorine dioxide, bleach, etc.,3) the apparatus used to produce EW is relatively 

inexpensive and easy to operate, 4) because only water and sodium chloride (salt) are used in EW 

production, it is environmentally more friendly of a compound compared to some of the alternative 

materials, and 5) the properties of EW are controlled on site during the electrolysis process. It should also 

be mentioned that since the materials from both of the cathodes are actually used during this process and 

final product use, there are no bi-products created during the formulation of Electrolyzed Water and 

therefore nothing to dispose of or that could be considered to be of a negative environmental concern.

Discussion:

From an environmental impact perspective, EW would appear to pose less of a risk for the environment 

than some of the alternatives since it is made from water and salt. There are no by-products to be disposed 

of since all of the materials are formulated and used in the final application process. Also, it would appear 

that EW would pose less of a risk to human health and/or worker health compared to some of the possible 

alternative products as well. According to the August 13, 2015 TR hypochlorous acid at a pH 6.0 to 7.5 is 

safer to use that other disinfectants containing chlorine. The level of chlorine in EW is usually over ten 

thousand times less than that of common household bleach. The on-site production helps to alleviate the 

need to transport other materials that may be more hazardous to handle, thus reducing the risk of 

exposure to the worker and for possible environmental contamination if improperly handled. The optimum 

range for the material that previously was being used in organic farming or currently is being used (in 

conventional farming) is at a pH of 6.0 to 7.5 according to the petitioner. This pH range gives a more 

effective and a more stable product that is safer for the environment and human safety as well than those 

using the lower pH levels. According to the TR it mentions that in forms of hypochlorous acid that are at a 

pH<4.0, dissolved chorine gas can be rapidly lost due to volatilization, decreasing the biocidal effectiveness 

of the solution over time, but also creating possible human health and safety issues (Fisher, 2009). The 

more neutral, the pH of the material, the safer and more stable the substance appears to become.

The primary functions of EW are as an anti-microbial, sporicidal, and bactericidal agent. Some currently 

allowed alternatives to EW are: Sodium and/or calcium hypochlorite (bleach), isopropanol, chlorine dioxide, 

peroxyacetic acid, citric acid, acetic acid, ascorbic acid, vinegar are some of the materials currently used.

The petition seeks to add electrolyzed water/hypochlorous acid to the National List for use in organic crop 

production as an alternative to the other substances currently allowed. The petitioner states that EW will 

be used post-harvest on farm as a sanitizer for use on raw herbs and spices including, but not limited to; 

basil, cilantro, parsley, chili peppers, garlic, and ginger. EW would also be used on farm to sanitize 

equipment and as a cold room sanitizer.

Electrolyzed water, although produced via a different mechanism, has the same mode of action as sodium 

and calcium hypochlorite (both of these materials are currently on the National List). In fact, the main 

active ingredient in their dilute aqueous solution form is hypochlorous acid, the same material produced as 

the Anolyte component of electrolyzed water. The reason hypochlorous acid can be ten thousand times 

less concentrated than sodium and calcium hypochlorous solutions and still be an effective sanitizer is that 

sodium and calcium hypochlorite solutions (bleach) have a high pH. When the pH is high, the hypochlorous 

acid/hypochlorite chemical equilibrium strongly shifts towards the presence of hypochlorite, whereas at 

neutral pH the chemical equilibrium shifts towards the presence of hypochlorous acid, the effective 
sanitizing compound. Therefore, hypochlorous acid (EW) is a safer product, for the environment and for 

human health, than chlorine sanitizer materials currently on the National List.

During the public comment period prior to the fall 2014 NOSB meeting there were several public comments 

submitted in response to the NOP’s decision to halt the allowed use of Hypochlorous acid per their memo 

PM 14-3 sent out on June 9, 2014. One of those organic stakeholders provided written public comment on 

September 28, 2014 that included multiple peer-reviewed scientific journal articles. These articles provided 

support to the claim that electrolyzed water was a safe sanitizer, providing the same degree of antimicrobial control without the toxic risk to employees, the crops, or the harvested products it is applied to. 

These articles also helped to provide support that this material might better support the basic fundamental 

principles of organic crop production compared to many of the alternatives currently being used. These also 

helped to support the petitioners claim as to why this material is needed – because it is safer to use on such 

crops as lettuce, spinach, and other sensitive vegetables and herb crops.

This material does appear like it could help the organic crop producers meet the requirements of 

compliance with the FDA’s Food Safety Modernization Act, while at the same time providing the producer 

with a material more compatible with the fundamental principles of organic crop production. It could 

possibly be looked at to provide a material that is less concerning for its impact on human and 

environmental health, while helping to meet a necessary need of the organic producer for materials that 

they can use in the sanitizer/anti-microbial listing for use in organic crop production.

Evaluation Criteria (see attached checklist for criteria in each category)

Criteria Satisfied? 

1. Impact on Humans and Environment ☒ Yes ☐ No ☐ N/A 

2. Essential & Availability Criteria ☒ Yes ☐ No ☐ N/A

3. Compatibility & Consistency ☒ Yes ☐ No ☐ N/A 

Subcommittee Action & Vote

Classification Motion: Move to classify hypochlorous acid as synthetic.

Motion by: Harold V. Austin IV 

Seconded by: Francis Thicke

Yes: 7 No: 0 Absent: 0 Abstain: 0 Recuse: 0

Listing Motion: Move to list hypochlorous acid at §205.601 of the National List: Synthetic substances 

allowed for use in organic crop production. §205.601(a) As algicide, disinfectants, and sanitizer.

(2)chlorine materials (iv) Hypochlorous acid.

Motion by: Harold V. Austin IV 

Seconded by: Emily Oakley

Yes: 7 No: 0 Absent: 0 Abstain: 0 Recuse: 0

Approved by Zea Sonnabend, Subcommittee Chair, to transmit to NOSB February 16, 2016
NOSB Evaluation Criteria for Substances Added To the National List – Crops

Category 1. Adverse impacts on humans or the environment?Hypochlorous acid

Question Yes No N/A Comments/Documentation (TAP; petition; 

regulatory agency; other)

1. Is there a probability of environmental 

contamination during use or misuse? 

[§6518(m)(3)]

x According to the petition electrolyzed water 

can be made on-site. In this process there 

would not be any residual product to dispose 

of. If produced off-site and sold as a finished 

product then there could be a possibility of 

environmental contamination as the result of 

an accident or a spill. The TR does state that

in forms of hypochlorous acid that are at a 

pH<4.0, dissolved chlorine gas can be rapidly 

lost due to volatilization, decreasing the 

biocidal effectiveness of the solution over 

time, but also creating possible human 

health and safety issues (Fisher, 2009). The 

more neutral, the pH of the material, the 

safer and more stable the substance appears 

to become.

2. Is there a probability of environmental 

contamination during, manufacture or 

disposal? [§6518(m)(3)]

x This substance is formed by the electrolysis 

of a sodium chloride solution. Any 

environmental concerns would be from a 

spill during manufacturing or transport of a 

formulated end product.

3. Are there any adverse impacts on 

biodiversity? (§205.200)

x The TR, (lines 596-612) does state that 

hypochlorous acid in aqueous solutions at 

pH< 7. Was of minimal toxicity to birds, but 

could be very toxic to fish and freshwater 

invertebrates. 

4. Does the substance contain inerts classified 

by EPA as ‘inerts of toxicological concern’? 

[§6517 (c)(1)(B)(ii)]

x Contaminants listed in the US Food and Drug 

Administration’s Guidance for Industry: 

Action Levels for Poisonous or Deleterious 

Substances in Human Food and Animal Feed, 

are unlikely to be found in hypochlorous acid 

since it is the electrolysis product of two 

generally recognized as safe materials, salt 

and water (TR lines 568-571).

5. Is there potential for detrimental chemical 

interaction with other materials used in 

organic farming systems?

[§6518(m)(1)]

x The TR (lines 140-153) mentions that there 

can be a reaction with organic material 

(humic acid) which can lead to some

potential concerns. It does go onto state 

though: It is generally accepted that 

carcinogenic and teratogenic 

trihalomethanes and haloacetic acids are not 

formed by the action of hypochlorous acid in 

neutral or near-neutral solutions (Satyawli et 

al., 2007). 
6. Is there a toxic or other adverse action of the 

material or its breakdown products?

[§6518(m)(2)]

x

7. Is there persistence or concentration of the 

material or breakdown products in the 

environment? [§6518(m)(2)]

x According to the TR (lines 602-612) 

hypochlorous acid solution decomposes very 

slowly in the dark but more rapidly in the 

presence of light, rapidly in full sun light by 

producing hydrogen chloride and oxygen. 

Released into the environment it is 

distributed into water and air, with an 

estimated half-life of 1-4 hours. A potential 

for bioaccumulation or bioconcentration of 

active chlorine species can be disregarded, 

because of their water solubility and their 

high reactivity.

8. Would the use of the substance be harmful 

to human health or the environment? 

[§6517 (c)(1)(A)(i); §6517 (c)(2)(A)(i); 

§6518(m)(4)]

x Information provided in the petition states 

that compared to other types of chlorine, 

electrolyzed water is usually used at an 

active rate that is ten thousand times less 

than that of common household bleach. The 

TR (lines 624-626) mentions that the human 

innate immune system uses hypochlorous 

acid to fight infection but also directs it 

against host tissue in inflammatory diseases 

(Kettle et al.,2013). Chlorine disinfectants 

have been shown to cause occupational 

dermatitis or skin irritation (TR line 662).

9. Are there adverse biological and chemical 

interactions in the agro-ecosystem? 

[§6518(m)(5)]

x See the answer to question #5 above.

10. Are there detrimental physiological effects 

on soil organisms, crops, or livestock? 

[§6518(m)(5)]

x

Category 2. Is the Substance Essential for Organic Production? Hypochlorous acid

Question Yes No N/A Comments/Documentation (TAP; petition; 

regulatory agency; other)

1. Is the substance agricultural? [§6502(1)] x

2. Is the substance formulated or 

manufactured by a chemical process? 

[§6502(21)]

x Electrolyzed water is the product of the 

electrolysis of a dilute sodium chloride 

solution in an electrolysis cell containing a 

semi-permeable membrane. This process 

creates hypochlorous acid, hypochlorite ion, 

and hydrochlorite at the anode and sodium 

hydroxide at the cathode. (TR lines 48-68) 

August 13, 2015 TR.

3. Is the substance formulated or 

manufactured by a process that chemically 

x
changes a substance extracted from 

naturally occurring plant, animal, or mineral 

sources? 

[§6502(21)]

4. Is the substance created by naturally 

occurring biological processes? 

[§6502(21)]

x

5. Is there a natural source of the substance? 

[§ 205.600(b)(1)]

x

6. Is there an organic substitute? 

[§205.600(b)(1)]

x Organic acids such as citric acid, lactic acid, 

malic acid, and vinegar are some alternative 

materials. 

7. Is there a wholly natural substitute product?

[§6517(c)(1)(A)(ii)]

x Hot water can be used in some instances. 

8. Are there any alternative substances? 

[§6518(m)(6)]

x Some alternative substances are: Sodium 

and/or calcium hypochlorite (bleach), 

isopropanol, chlorine dioxide, peroxyacetic 

acid, citric acid, acetic acid, ascorbic acid, and 

vinegar. Copper sulfate is another possible 

alternative depending on the use. 

9. Are there other practices that would make 

the substance unnecessary? [§6518(m)(6)]

x

Category 3. Is the substance compatible with organic production practices? Hypochlorous acid

Question Yes No N/A Comments/Documentation (TAP; petition; 

regulatory agency; other)

1. Is the substance consistent with organic 

farming and handling? 

[§6517(c)(1)(A)(iii); 6517(c)(2)(A)(ii)]

x Compared to many of the alternative 

materials currently being used electrolyzed 

water could provide a safer and effective 

alternative. (especially when produced using 

the on-site electrolysis process)

2. Is the substance compatible with a system of 

sustainable agriculture? [§6518(m)(7)]

x See answer to question #1 of this category.

3. If used in livestock feed or pet food, is the 

nutritional quality of the food maintained 

with the substance? [§205.600(b)(3)]

x

4. If used in livestock feed or pet food, is the 

primary use as a preservative? 

[§205.600(b)(4)]

x

5. If used in livestock feed or pet food, is the 

primary use to recreate or improve flavors, 

colors, textures, or nutritive value lost in 

processing (except when required by law)? 

[§205.600(b)(4)]

x
6. Is the substance used in production, and 

does it contain an active synthetic ingredient 

in the following categories:

[§6517(c)(1)(B)(i);

copper and sulfur compounds

x

toxins derived from bacteria x

pheromones, soaps, horticultural oils, 

fish emulsions, treated seed, vitamins 

and minerals

x

livestock parasiticides and medicines x

production aids including netting, tree 

wraps and seals, insect traps, sticky 

barriers, row covers, and equipment 

cleansers

x May be used to sanitize equipment