This is a proposal by a Subcommittee of the National Organic Standards Board (NOSB). Proposals are posted for public comment and 

then may be voted upon by the full Board. They are not final Board recommendations or NOP policy.

National Organic Standards Board

Crops Subcommittee

Petitioned Material Proposal

Laminarin

+February 26, 2014

Introduction

The NOSB received a petition for Laminarin, a seaweed extract for disease control that is 

allowed by EPA for that purpose.

Background

From the Laminarin petition:

5. The source of the substance and a detailed description of its manufacturing or 

processing procedures from the basic component(s) to the final product.

Stage 1: Fresh Laminaria digitata seaweed, harvested on the North Brittany coast of France, 

undergoes extraction in tap water that has a pH adjusted to 2 by addition of sulfuric acid. At this 

stage sulphuric acid is a processing aid. Laminarin can be extracted at neutral pH or in acidic 

conditions. The described acidic conditions do not modify the chemical structure of laminarin. 

The addition of sulfuric acid avoids the co-extraction of other compounds such as alginates 

(which occurs at neutral pH). When alginates are extracted, the solution has a higher viscosity; 

purification and filtration steps for laminarin then become much more difficult. This is the reason 

why sulphuric acid is used to lower the pH and to facilitate the manufacturing process.

Stage 2: The extract is then filtered using a Seitz filter.

Stage 3: The solution then undergoes tangential filtration (membrane technology – physical 

process) to remove impurities from the solution. The filtrate containing laminarin is kept for the 

next purification step and the retentate is removed.

Stage 4: The filtrate (see above) then undergoes a second tangential filtration to remove any 

remaining impurities (filtrate), thereby resulting in a purified solution of laminarin in water 

(retentate).

Stage 5: The pH is adjusted between 6 and 7 by adding sodium hydroxide to neutralize the 

acidic solution, resulting in a solution of laminarin at neutral pH for formulation purposes (i.e., 

Vacciplant formulation). The addition of dilute sodium hydroxide does not modify the chemical 

structure of laminarin.

From the note from NOP to Crops Subcommittee, 6/3/13:

In NOP’s review of the eligibility of this petitioned substance for the National List, we reviewed 

the manufacturing process against the draft guidance on classification of materials (NOP 5033). 

Based on our preliminary review, this substance may be classified as nonsynthetic. We have 

moved this petition forward for NOSB review and final determination on the classification status 

for the following reasons:

o The classification guidance is currently in draft form

o Other aquatic plant extracts are classified as synthetic for crop production at 

205.601(j)(1)

o At this time, NOP is not aware of any products containing laminarin as an 

active ingredient that are approved by certifying agents or third-party 

material review organizations, such as EPA or OMRI

Discussion
This is a proposal by a Subcommittee of the National Organic Standards Board (NOSB). Proposals are posted for public comment and 

then may be voted upon by the full Board. They are not final Board recommendations or NOP policy.

The Crops subcommittee also reviewed the manufacturing process against the draft guidance 

on classification of materials (NOP 5033, section 4.6):

4.6 Extraction of Nonorganic Materials

Some materials are produced using manufacturing processes that involve separation 

techniques, such as the steam distillation of oil from plant leaves. Separation and 

extraction methods may include, but are not limited to, distillation, solvent extraction, acidbase extraction, and physical or mechanical methods (e.g., filtration, crushing, 

centrifugation, or gravity separation).

For purposes of classification of a material as synthetic or nonsynthetic, a material may be 

classified as nonsynthetic (natural) if the extraction or separation technique results in a 

material that meets the following criteria:

• At the end of the extraction process, the material has not been transformed into a 

different substance via chemical change; 

• The material has not been altered into a form that does not occur in nature; and 

• Any synthetic materials used to separate, isolate, or extract the substance have 

been removed from the final substance (e.g., via evaporation, distillation, 

precipitation, or other means) such that they have no technical or functional effect 

in the final product.

The majority of the subcommittee has determined that Laminarin is extracted by an acid-base 

extraction and meets the criteria in section 4.6 above.

In regards to the third bullet point above the subcommittee majority believes that the acid-base 

reaction itself neutralizes any of the sulfuric acid starting material to the degree that it has no 

technical or functional effect. The minority opinion tries to draw parallels between laminarin 

which is extracted and then used to boost the plant's immune defenses against disease with 

sulfuric acid used to stabilize manure (a petition that was rejected) or acids used to stabilize fish 

products listed on §205.601. The majority feels these comparisons are not relevant because of 

the acid being used in substantially greater quantities in manure and fish, and the fact that they 

are both fertilizers means that the residual sulfates or phosphates would have a functional effect

in the fertilizers. Laminarin is used for disease control at a rate of 0.52 - 1.04 fl. oz. per acre (as 

stated in the petition) which would not provide a functional effect from some parts per million of 

that rate being sulfate.

Because of a determination that it is non-synthetic, the subcommittee has not filled out a 

checklist as it does not need to be added to the National List.

Minority Opinion

A minority of the Subcommittee supported the view that laminarin is synthetic because sulfuric 

acid is added but not removed. Sodium hydroxide is added to neutralize sulfuric acid, but the 

sodium sulfate produced by the neutralization reaction (which does not chemically change 

laminarin) is not removed.

The minority agrees that laminarin does not undergo chemical change in the extraction process. 

Unfortunately, however, the NOP decision tree is incomplete –it does not cover all of the criteria 

in the guidance document NOP 5033. The guidance document states, “Some materials may be 

considered synthetic due to chemical changes which occur during manufacturing, while others 

substances may be classified as synthetic due to addition of small amounts of synthetic 

ingredients.”
This is a proposal by a Subcommittee of the National Organic Standards Board (NOSB). Proposals are posted for public comment and 

then may be voted upon by the full Board. They are not final Board recommendations or NOP policy.

In the case of laminarin, we need to look at the synthetic ingredients that are added. The section 

on extraction in the NOP guidance states that in order for a material to by classified as 

nonsynthetic, “Any synthetic materials used to separate, isolate, or extract the substance have 

been removed from the final substance (e.g., via evaporation, distillation, precipitation, or other 

means) such that they have no technical or functional effect in the final product.”

The extraction of laminarin involves the addition of sulfuric acid, as described in the petition. The 

sulfuric acid is not removed. Sodium hydroxide is added to neutralize the acid, but the sulfate 

remains. While there is no definition of “technical or functional effect” in the NOP regulations or 

the guidance, our calculations suggest that the amount of sulfate and sodium added to laminarin 

in the extraction process is significant.

The minority does not claim that the sulfate in laminarin constitutes a synthetic plant nutrient 

because it is not used in quantities that would be significant nutritionally to plants. Rather, the 

claim is that the sulfate is a significant residue within the laminarin that is not removed.

Some relevant points that we considered:

1. Sulfuric acid is added during the extraction of laminarin to reduce the pH to 2. Later, it is 

neutralized with the addition of the base sodium hydroxide. Although the sulfuric acid is 

neutralized, it is not removed. We calculate that altogether, 624 parts per million (ppm) 

sulfate and 299 ppm of sodium are added.1 Because the kelp provides some (unknown) 

buffering capacity, the quantities are probably somewhat higher than this calculation 

indicates.

2. The NOSB has previously found (in 2006 and 2012, for anaerobic digestion of livestock 

and poultry manure) that the addition of sulfuric acid, even when followed by a step that 

neutralizes the acid, leaves behind a significant synthetic residue that has a functional 

effect in the agricultural system.

3. OMRI regards sulfuric acid and sulfate as prohibited, with limited specific exceptions.

4. The listing of liquid fish products is an instructive precedent indicating that when pH is 

adjusted with a synthetic, the product should be classified as synthetic.

Subcommittee Action & Vote

Classification Motion: 

Motion to classify Laminarin as nonsynthetic

Motion by: Zea Sonnabend 

Seconded by: Harold Austin

Yes: 5 No: 2 Absent: 0 Abstain: 0 Recuse: 0

Because laminarin was classified as non-synthetic, no further action by the Crops 

Subcommittee is necessary.

Approved by Zea Sonnabend, Subcommittee Chair, to transmit to NOSB February 26, 

2014

 1 Compare this concentration to the Secondary Maximum Contaminant Level of sulfate in 

drinking water and the EU standard for drinking water --both 250 ppm.