National Organic Standards Board 

Crops Subcommittee 

Petitioned Material Proposal 

Sodium Carbonate Lignin 

August 4, 2020 

Summary of Petition: 

Sodium carbonate lignin has been petitioned for use in organic crop production through addition to the 

National List at 205.601(j)(4) of "lignins" as a dust suppressant. Lignin sulfonate, another type of lignin, 

is currently listed at 205.601(j)(4) for use as a chelating agent and dust suppressant. The petitioned 

material results from a paper pulping process that uses sodium carbonate and sodium hydroxide to 

extract lignin. Lignins found in plant cell walls are amorphous, complex biopolymers. Lignins make up 

20-30 percent of plant cell walls, 30 percent of the total mass in softwood, 20-25 percent of the total

mass in hardwoods and a smaller percentage of the total mass of herbaceous species. Commercial

lignins are obtained as byproducts of the bioethanol and paper pulping industries.

Sodium carbonate lignin has a variety of potential uses. Lignins are used for binding and are added in 

fertilizer formulations to improve granule formation by binding extrusion granules. They also prevent 

fertilizer caking during storage. Lignins are also used for dust suppression. They are useful as binders in 

fertilizer and feed formulation because improving the quality of the pelletizing or granulation of these 

materials is a well-known measure for dust suppression. Adding binders such as lignin increases 

fertilizer granule strength, thereby reducing the formation of dust . Lignins have also been sprayed on 

roads for dust control. 

Lignins are used to chelate micronutrients in fertilizer formulations to form more stable, yet still soluble, 

complexes that improve plant micronutrient availability. 

Summary of Review: 

At this time there has not been any public comments on sodium carbonate lignin, but lignin sulfonate 

has been reviewed and public comments on this product have been positive for relisting during sunset 

review. A survey of regulations for organic production from a number of countries and international 

organizations indicates that the use of sodium carbonate lignin is not generally permitted while lignin 

sulfonate is approved by many of the international organizations. 

Category 1: Classification 

1. For CROP use: Is the substance Non-synthetic or X Synthetic?

Is the substance formulated or manufactured by a process that chemically changes a substance

extracted from naturally occurring plant, animal, or mineral sources? [OFPA §6502(21)] If so,

describe, using NOP 5033-1 as a guide.

The petition describes the process used to manufacture sodium carbonate lignin both as soda

ash pulping and soda pulping. Wood chips are subjected to a solution of either sodium

carbonate or a combination of sodium carbonate and sodium hydroxide and coked in steam

under pressure for 15 minutes. The cooked wood chips are then mechanically pressed to

separate the spent cooking liquor which is then evaporated to a dry powder. Lignin is a natural

product that is chemically altered to become synthetic.

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2. Reference to appropriate OFPA category:

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; toxins derived from

bacteria; pheromones, soaps, horticultural oils, fish emulsions, treated seed, vitamins and

minerals; livestock parasiticides and medicines and production aids including netting, tree wraps

and seals, insect traps, sticky barriers, row covers, and equipment cleansers; or (ii) is used in

production and contains synthetic inert ingredients that are not classified by the Administrator

of the Environmental Protection Agency as inerts of toxicological concern?

The petitioner is requesting that sodium carbonated lignin to 7 CFR 205.601(j)(4) as a synthetic

substance allowed for use in organic crop production as a plant and soil amendment for dust

suppression in addition to lignin sulfonate.

Category 2: Adverse Impacts 

1. What is the potential for the substance to have detrimental chemical interactions with other

materials used in organic farming systems? [§6518(m)(1)]

Soil stabilization with sulfur-free lignin has been studied and application of the lignin was found

to slightly decrease soil pH, but was still comparable to the pH of natural soil. Different types

of lignin phenols can be inhibitory to some fungal species, but they may also stimulate microbial

activity depending on the amount of lignin applied. The use of the petitioned substance for dust

control has the potential to increase soil aggregate size and water retention, which some

researchers suggest may be ecologically beneficial.

2. What is the toxicity and mode of action of the substance and of its breakdown products or any

contaminants, and their persistence and areas of concentration in the environment?

[§6518(m)(2)]

Environmental studies over the last 30 years have shown lignin sulfonates to be nontoxic at 

concentrations above those used (TR 621). Lignins have been shown to be an important 

precursor in the formation of humic substances (TR 601) and they can increase soil organic 

carbon and total nitrogen. Lignins are toxic in wastewater streams from the paper pulping 

process and can be toxic to aquatic organisms. Using lignin sulfonates in organic farming could 

benefit the environment by removing them from the paper manufacturing process waste 

stream. 

3. Describe the probability of environmental contamination during manufacture, use, misuse or

disposal of such substance? [§6518(m)(3)]

There are four pulping processes that make up the majority of production methods. As one

study reported, the soda process has the lowest potential environmental impact as measured by

a waste reduction algorithm developed by the EPA's National Risk Management Research

Laboratory. None of the literature reviewed by the 2020 Technical Review suggested that the

use of lignins as petitioned would result in environmental contamination of organic systems.

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4. Discuss the effect of the substance on human health. [§6517(c)(1)(A)(i); §6517(c)(2)(A)(i);

§6518(m)(4)].

In the Technical Review performed in 2020 a review of environmental studies of the last 30 

years found that lignin sulfonates are nontoxic at the concentration used. In fact, it was stated 

that worker safety is improved with the use of lignins as dust suppressants in preventing dust 

inhalation when workers dispense fertilizers, and also obviates the need for wearing respirators. 

The U.S. EPA issued an exemption from the requirement of a tolerance for lignin sulfonates 

when they are used as inert ingredients pre- and post-harvest in agricultural product and the 

same would be expected for lignin carbonates. 

5. Discuss any effects the substance may have on biological and chemical interactions in the

agroecosystem, including the physiological effects of the substance on soil organisms (including

the salt index and solubility of the soil), crops and livestock. [§6518(m)(5)]

The use of the petitioned substance is for dust control in the context of a plant or soil

amendment and as such, is applied to the soil at relatively low rates. As the Technical Report

stated, this consideration with the potential effects of lignin to increase soil aggregate size and

water retention and enhance microbial activity, suggest that its use as petitioned is likely to be

benign and may even be ecologically beneficial.

6. Are there any adverse impacts on biodiversity? (§205.200)

At the rates this substance is applied, no adverse impacts on biodiversity are expected.

Category 3: Alternatives/Compatibility 

1. Are there alternatives to using the substance? Evaluate alternative practices as well as nonsynthetic and synthetic available materials. [§6518(m)(6)]

OMRI has 11 products listed in the category of "Dust Suppressants" and another 29 in the

category of "Lignin Sulfonates." Many of these products contain wax emulsions or combinations

of oil and wax emulsions. Also vegetable oils, magnesium or calcium chloride solutions, glycerin

and natural fatty acids are also used. Their effectiveness over time may decrease as oils

volatilize or become adsorbed in fertilizer particles and waxes and oils have limited binding

capacity. Other nonsynthetic fibrous materials have been suggested and include wood flour,

peat moss, compost, manure, cotton, straw and clay. Dust suppression for roads can also

include management practices such as maintaining vegetative cover in non-traffic areas,

mulching, application of stone or gravel to disturbed roads and air current barriers such as trees.

In reviewing the petition, the Crop Subcommittee feels that there is no need to add another

synthetic lignin product for dust suppression since numerous lignin alternatives already are

available for use.

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2. In balancing the responses to the criteria above, is the substance compatible with a system of

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

Yes, sodium carbonate lignin, when used in fertilizer as a dust suppressant, allows finer particles

to be produced. These smaller particles allow faster breakdown and with moisture, more

immediate nutrients are available to plant life. Additionally, removing lignins from the paper

pulping industry and repurposing them to organic farming use prevents a source of lignin

contamination in discharge in wastewater. However, given that there are viable alternatives

already on the National List, the Crops Subcommittee feels that there is no need to add another

synthetic lignin product for dust suppression.

Classification Motion: 

Motion to classify sodium carbonate lignin as synthetic 

Motion by: Rick Greenwood 

Seconded by: Dave Mortensen 

Yes: 6 No: 0 Abstain: 0 Absent: 2 Recuse: 0 

National List Motion: 

Motion to add sodium carbonate lignin at 205.601 (j)(4) 

Motion by: Rick Greenwood 

Seconded by: Steve Ela 

Yes: 0 No: 6 Abstain: 0 Absent: 2 Recuse: 0 

Approved by Jesse Buie, Crop Subcommittee Chair, to transmit to NOP August 4, 2020 

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