National Organic Standards Board

Crops Subcommittee Proposal

Biodegradable Biobased Mulch Film 

February 16, 2021

I. Summary of biodegradable biobased mulch film

The NOP rescinded policy memorandum 15-1 in October 2019, stating that it was redundant with 

current regulations. The requirement for 100% biobased feedstocks is articulated in the preamble of the 

final rule and the status quo remains. Removal of the policy memorandum provides an opportunity for 

the NOSB to revise the current definition (§ 205.2) to reduce the biobased content requirement. The 

Crops Subcommittee is now planning to vote on an annotation at the Spring 2021 meeting addressing 

biodegradable mulch (BDM) film that is not 100% biobased.

II. Discussion: 

Biodegradable biobased mulch film has been on the National List of approved synthetic substances since 

September 30, 2014, based on an October 2012 NOSB recommendation. Historical information on this 

material is as follows:

Reference on the National List: § 205.601(b) As herbicides, weed barriers, as applicable (2) Mulches (iii) 

Biodegradable biobased mulch film as defined in §205.2. Must be produced without organisms or 

feedstock derived from excluded methods.

Technical Report: 2012 TR; 2015 Report; NOP Policy Memorandum 15-1; Supplemental Technical

Evaluation Report 2016

Petition(s): 2012

Past NOSB Actions: 10/2012 NOSB Recommendation; Memo to the NOSB with Report on Biodegradable 

Biobased Mulch Films in Organic Crop Production (Michigan State University, September 2019) (pdf).

Recent Regulatory Background: Final Rule published 09/30/14 (79 FR 58655); Sunset renewal notice 

published 10/08/2019, 84 FR 53577

Background from Subcommittee: Biodegradable biobased mulch films were approved for placement on 

the National List of approved synthetics (Biodegradable Mulch Film Made from Bioplastics) without 

detailing if non-biobased content would be allowed. Most mulch films in this category contain 20% or 

less of biobased materials (i.e., they are ~80% petroleum derived), with the remainder consisting of 

polymers, colorings, and other synthetic materials. There are some products that might meet the 

biobased aspect of this material’s definition on at §205.2 but are either not biodegradable or are not 

used in production due to brittleness or other production issues.

In January 2015, the National Organic Program issued Policy Memorandum 15-1, to clarify that 

biodegradable biobased mulch film must not contain any non-biobased synthetic polymer feedstocks. 

The NOSB requested a limited scope technical report (TR) in 2016. The questions asked for this limited 

scope TR from 2016 were as follows:

1. What is the effect on overall soil health, including soil biology, when this materialbiodegrades?

2. What is the cumulative effect of the continued use of this biodegradable biobased mulch film, 

on soil nutrient balance, soil biological life, and soil tilth, when used in the same area of the 

field for 3-5-10 years?

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3. What effect does the breakdown of these polymers have on soil and plant life as well as 

livestock that would graze either crop residues or forages grown the subsequent year after this 

mulch film was used?

4. Are there different cropping systems, climate, soil types or other factors that affect the 

decomposition rate (Examples would be long cold winters, or exceptionally dry conditions, 

such as found in a desert)? 

5. Are there metabolites of these mulches that do not fully decompose, and if so, is there an 

effect upon soil health or biological life? 

The TR focused on biobased biodegradable mulches that contain polymers and the soil and crop health 

effects they may have as they biodegrade. This supplemental TR was inconclusive, since research on 

these materials is currently limited, and the questions above were not answered to the NOSB crop 

subcommittee’s satisfaction. 

An argument can be made that even though the non-biobased polymers degrading into the soil 

originate from petroleum (a nonrenewable fossil fuel), the use of this product could be considered 

environmentally friendly because: 

• Many organic production systems rely on enormous amounts of plastic, mostly polyethylene 

 (PE) films, to produce organic crops;

• PE films likely shed micro plastics and leach chemicals into organic soil over the growing season;

• Before and during removal, PE films can tear and breakdown, leaving plastic in the soils or 

 migrating off-site into aquatic habitats;

• PE films are generally not recyclable due to contamination by soils or the lack of recycling 

 infrastructure; 

• Plastic used in annual production systems end up in landfills; 

• Biodegradable mulches potentially save labor and time, since the mulch does not have to be 

 removed from the field and transported for disposal;

The current listing of biodegradable mulch on the National List is aspirational: there are no products on 

the market that are commercially viable made from 100% biobased carbon sources (i.e., no petroleum). 

In fact, some public commenters have recommended that BDM films be taken off the National List since 

the 100% biobased requirement essentially prohibits use of these materials. However, the NOSB 

reviewed this material for its five-year sunset renewal in 2017, and decided to relist it as written, with 

understanding that there were no products on the market that were commercially viable made from 

100% biobased (no petroleum) materials. The crops subcommittee needed more information that 

addressed the key questions above to consider a change to the annotation. If it remained on the 

National List, the Board also hoped manufacturers would be able to develop a product that met that 

requirement of 100% biobased “ingredients”, which was the preferred outcome.

The National Organic Program also reached out to Dr. Ramani Narayan, a researcher with the 

Department of Chemical Engineering and Materials Science at Michigan State University to provide 

more information beyond the technical review, which was completed in 2016, to the NOSB. The focus of 

Dr. Narayan’s report is the biodegradability of both biobased and petroleum-based mulch films with 

limited research on the effect of these products degrading into the soil over time. Section 2.7 of the 

reportstates:

Environmental studies have not shown any adverse impacts associated with the incorporation of 

biodegradable mulch films (BDMs) into the soil to date. More research is needed to monitor any 

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potential formation of terrestrial micro and nanoplastics from biodegradable mulch films and ensure 

that there is no residual soil ecotoxicity. There is need for tuning the physicochemical properties of the 

biodegradable mulch films with the needs of specific cropping systems and climates. The biodegradable 

mulch films could provide additional environmental benefits by formulating them to deliver macro and 

micronutrients to the crop as they biodegrade in soil, or deliver pesticides directly into the soil. Sintim et 

al. showed that there was no significant effect on soil health over two years of monitoring and that the 

soil microbial communities did not differ much either. They found significant enrichment in bacterial and 

fungal gene copies under BDM treatments over 2 years, but no significant change under PE and no 

mulch. Another important observation was that repeated tillage of BDMs into the soil across 4 years did 

not impact crop yield significantly and had no major effect on crop quality. 

While this section points out possible negative issues with some polymers used in the biodegradable 

mulch, most of the report focused on the positive aspects when the mulch does biodegrade. The report 

also discussed current regulations that protect organic integrity and would not allow the use of excluded 

methods (some of the polymers are extracted from petroleum through the use of bacteria created 

through excluded methods) and do not allow materials to be used that “contribute to contamination 

crops, soil or water.” Organic producers in the European Union are allowed to use petroleum based 

biodegradable mulch with no requirement on the percentage of bio-based ingredients. The EU will be 

reviewing these mulches in 2024 with possible changes to their annotation.

Key concerns of current and past NOSB members include the possibility of soil, aquatic, and other 

environmental contamination by partially decomposed BDM films even if the materials pass ASTM 

laboratory-based standards. Of particular concern to NOSB members is the possibility that BDM films 

will not decompose thoroughly in dry or cold environments where there is less biological activity in soils. 

A related concern is that BDM films ploughed into soils may be out of reach of peak biological activity to 

break it down. For example, most soil biological activity occurs in the top 4-6 inches, with only a small 

fraction below that level. If ploughing results in BDM film plastic mixed into soil 7-10 inches deep, there 

may be fewer microbiotic fauna available to consume BDM carbon sources.

Extensive public comments and up-to-date scientific reviews have been submitted to the NOSB, and in 

some cases submitters note sampling and/or other analytic methods are not yet developed enough to 

answer all questions about potential residues in soil.

The Board has also weighed the merits of comparing the risk to soils and the environment from BDM 

films versus risk from PE films. Board members are torn on this issue. Current use of plastic in organic 

production is increasing rapidly. Some small- and large-scale growing systems, such as organic 

“plasticulture” strawberry production, are highly dependent on PE films, with thousands of acres of 

plastic used annually across the industry. Board members are also concerned about the precedent of 

allowing petroleum-derived products to be added directly to soils. The comparative risk of the two 

production aids leaves some organic community members uncomfortable. In essence, the thinking is “I 

don’t think the reason to add a new material to the National List should be because we’re trying to 

mitigate the harms caused by another NL material.” 

Precedents of Allowing the Addition of Petroleum Products to Soil

The National List currently allows the use of horticultural oils in crop production, including mineral oils 

refined from petroleum. Mineral oils are closer in chemistry to petroleum jellies and paraffin, versus 

other more volatile and toxic petroleum constituents. However, these materials pose some

environmental and health risks, and their use on crops results in direct entry into soil ecosystems. 

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At this meeting (April 2021), the NOSB is also proposing allowance of paper pots as planting aids, with 

the listing to read as follows 

Paper-based crop planting aid. A material that is comprised of at least 60% cellulose-based fiber by 

weight, including, but not limited to, pots, seed tape, and collars that are placed in or on the soil and 

later incorporated into the soil, excluding biodegradable mulch film. Up to 40% of the ingredients can be 

non-synthetic, other permitted synthetic ingredients at §205.601(j), or synthetic strengthening fibers, 

adhesives, or resins. Contains no less than 80% biobased content as verified by a qualified third-party 

assessment (e.g. laboratory test using ASTM D6866 or composition review by qualified personnel). 

Added nutrients must comply with §205.105, 205.203, and 205.206.

This proposal requires 80% biobased content but allows 20% of the material to be non-biobased, 

potentially including nylon and other non-biodegradable plastics in the paper pots. The paper-pot 

proposal is notable because it allows the direct application of non-biodegradable plastics to soil, 

although the long-term hope is that future products will be 100% biobased. Paper-pot production aids 

are generally used by small farmers and their contribution to soil plastics is likely to be small compared 

to the thousands of acres of soil covered by PE films and their possible future BDM film replacements.

Possible Use Restrictions

The Board has considered several options to guide use of BDM films if they are approved with less than 

100% biobased content. Specifically:

1. Allow BDM film use followed by ploughing into soil (with some consideration for off-site transport), 

with monitoring and assessment to determine whether there are adverse impacts; 

2. Restrict BDM film use based on soil types and climates where the BDM film may not biodegrade 

rapidly;

3. Allow BDM film use but require that it be gathered up at the end of the season followed by on-farm 

or off-farm composting.

In response to public comments, the Crops Subcommittee has concluded that Option 1, above, is the 

only reasonable option on which to vote. Soil types and climate are complex, and it is not possible to 

pre-identify regions and growing practices where use of the BDM films may or may not work (Option 2). 

Finally, Option 3 does not work because the films become brittle toward the end of the season and 

cannot be removed intact for later composting. 

III. Proposal

Weighing the risks and benefits of using PE and BDM films, the Crops Subcommittee proposes to allow 

BDM films that are at least 80% biobased by weight, with the remaining 20% by weight consisting of 

materials that meet one of the following composting standards: ASTM D6400, ASTM D6868, EN 13432, 

EN 14995, or ISO 17088 (all incorporated by reference; see § 205.3). The CS understands that this 

recommendation is still aspirational in the sense that no current BDM films meet the 80% biobased 

content criteria. However, several manufacturers have reported that producing 80% biobased film may 

be feasible, and this proposal sets a realistic goal. The CS also recommends that use of >80% biobased 

material be required if and when these materials become available. 

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The CS proposes the following annotation change for biodegradable biobased mulch film: 

§205.601 Synthetic substances allowed for use in organic crop production.

(iii) Biodegradable biobased mulch film as defined in §205.2. Must be produced without organisms or 

feedstock derived from excluded methods. When 100% biobased biodegradable plastic films become 

available, producers are required to use 100% biobased content BDM plastic films. 

§205.2.

Biodegradable biobased mulch film. A synthetic mulch film that meets the following criteria:

(1) Meets the compostability specifications of one of the following standards: ASTM D6400, ASTM 

 D6868, EN 13432, EN 14995, or ISO 17088 (all incorporated by reference; see § 205.3);

(2) Demonstrates at least 90% biodegradation absolute or relative to microcrystalline cellulose in less 

 than two years, in soil, according to one of the following test methods: ISO 17556 or ASTM D5988 

 (both incorporated by reference; see § 205.3); and

(3) Biodegradable plastic mulch films must be at least 80% biobased with content determined using 

 ASTM D6866 (incorporated by reference; see § 205.3).

III. Vote in Crops Subcommittee

Motion to accept the proposal on biodegradable biobased mulch film. 

Motion by: Asa Bradman

Seconded by: Rick Greenwood

Yes: 5 No: 1 Abstain: 0 Absent: 2 Recuse: 0

Approved by Rick Greenwood, Crop Subcommittee Chair, to transmit to NOP February 19, 2021.

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