Microplastic-free seed coatings that perform better than conventional ones: myth or reality ? Syensqo offer outclassed current products, even for oilseed rape !

Clara VERNAY Seed Care Center Laboratory Manager at Syensqo	Gonzague DE GASSART Seed Care Marketing Manager at Syensqo

Over the last decade, the impacts of microplastic spreading on the environment and on human health have been a hot topic raising concerns in the different geographical zones, leading to a European restriction on microplastics. Microplastics are solid particles of plastic material, composed of mixtures of polymers and functional additives. The ECHA estimated that more than 42 000 tons of microplastics are released into the environment every year. After years of discussion, the restriction on microplastics was finally adopted at the end of 2023 by the European Union regulatory instances with different phase-out periods, depending on the type of use. The restriction on microplastics is one of the most ambitious to-date and a flagship of the EU Green New Deal. With the application of this restriction, the ECHA estimated a reduction by 500 000 tons of the emission of microplastics over the next 20 years.

The final version of the restriction states that no product containing a weight concentration superior to 0.01% w/w of intentionally added microplastic shall be put on the EU market. In the text of the restriction, microplastic is defined as particles of certain dimensions, namely between 0.1 µm and 5 mm (for the case that interests us), containing a solid polymer, defined by the REACH committee as a sequence of more than 3 monomers. Among Agricultural activities, which accounts for about 10% of the total microplastic release, the seed coatings are directly concerned as they form a solid polymeric film at the surface of the seeds. In this case, the particle is the seed itself and the solid polymer is the seed coating film formed at the surface of the seed. The restriction does not apply if the polymers fall into one of the following categories:

• Liquid

• Natural origin without chemical modification

• Water-soluble with a solubility superior to 2 g/L

• Biodegradable, note that compostability tests are not accepted.

• Without carbon atoms in their structure

For seed coating, the transitional period was set at 5 years, meaning that it will be applicable starting from October 2028.

A careful design of microplastic-free formulations to anticipate the restriction, taking advantage from the broad chemical expertise of Syensqo*

For Syensqo Seed Care team, the work started a long time ago, more exactly in 2017, with the start of the re-formulation work to develop our microplastic free range of seed coatings.

Seed coatings are complex formulations with a dozen ingredients. The status of each of these ingredients had to be reviewed and alternatives identified to create our microplastic-free offer. A key point was to define the methodology to assess the microplastic-free status of the different raw materials. Thanks to its strong chemical expertise acquired during 160 years, Syensqo has set up a project team to evaluate its entire product portfolio. 

For the polymers produced by Syensqo, analytical studies are conducted to define the status towards the restriction, notably solubility analyses based on OECD method or biodegradability analyses based on OECD or ISO methods. 

For external raw materials, Syensqo’s assessment is based on declarations from our suppliers. However, we go beyond simple "non-microplastic" declarations. Syensqo asks each supplier to provide the arguments justifying the conditions of exemptions of the microplastics restriction. A "microplastic / non-microplastic" declaration from our supplier is not considered as the right level of information for Syensqo. Each supplier response is analyzed in depth. As a chemistry expert, we carry out our own independent assessment, so we may not accept supplier declarations if we consider that the raw material does not meet the conditions of exemptions. This in-depth work is a guarantee of quality for our microplastic-free products.

One of the first and most complete ranges of microplastic-free seed coatings. 

Thanks to this methodology, we are able to offer microplastic-free products, in line with our commitments on sustainability, without compromising the on-seed performances (good adherence of components of the coating on the seed, the reduction of dust emission, a better resistance to abrasion …).

The table 1 shows Syensqo's range of microplastic-free seed coatings, all bearing the motto "Zero Microplastic, Zero Compromise".

Table 1:  Syensqo's range of microplastic-free seed coatings, all bearing the motto "Zero Microplastic, Zero Compromise".

In a previous article, we presented one of our solutions for a strategic crop: corn, with Peridiam^® Quality 3001. 

A new microplastic-free solution for the challenging crop oilseed rape: an even more performant seed coating with Peridiam^® Quality 2001

Another challenging crop is Oilseed Rape, which is a plant resulting from a natural cross between cabbage and turnip. Rapeseed cultivation has grown steadily throughout the world, reaching around 35 million hectares annually nowadays. Among the 3 main species grown worldwide, Brassica napus varieties are grown in North America, Oceania and Europe whereas Brassica Juncea is the majority species in Asia.

The main producers of oilseed rape are:

Figure 1: Global repartition of the production of oilseed rape

Oilseed Rape is attractive not only for nutritional properties but also for pests like fungus, and insects (Aphids, flee beetles). The challenge with this crop is to apply effective and homogeneous protection to every single seed in a batch containing thousands of seeds.  A good layer of seed coating gives Oilseed Rape the best chance of becoming seedlings. With over 35 years of seed coating experience, Syensqo developped a new microplastic-free seed coating for oilseed rape: Peridiam^® Quality 2001. 

Figure 2 presents the comparative performances of Peridiam^® Quality 208 (current conventional grade) and Peridiam^® Quality 2001. Our new microplastic-free grade does not only provide comparable performance to Peridiam^® Quality 208 in most of the parameters but also offers superior performances regarding dust control, highlighting that microplastic-free is not a synonym of loss of performance.

Figure 2: Comparative performances of Peridiam^® Quality 208 (current standard) and Peridiam^® Quality 2001 (new microplastic-free grade)

Peridiam^® Quality 2001 comprises an innovative bio-based binder exempted from the microplastic restriction. It results from a very large screening of potential candidates to identify a technical solution matching the criteria of the microplastic regulation and ensuring excellent performances on seeds.

A key step for the development of Peridiam^® Quality 2001 was to validate the innocuousness of this novel binder on seeds. Seed safety studies were conducted on oilseed rape in different conditions in our biology laboratory located in our global Seed Care Center in Méréville, France. These studies validated that the new seed coating has no negative impact on germination.

For oilseed rape application, one of the biggest challenge is to obtain a good coverage and coloration of all the seeds due to their natural color and size. As highlighted in Figure 3, Peridiam^® Quality 2001 offers a very shiny and light blue visual aspect on seeds, very similar to the one obtained with the application of Peridiam^® Quality 208.

Figure 3: Visual aspect of oilseeds rape treated with Peridiam^® Quality 208 (conventional seed coating on the left) and Peridiam^® Quality 2001 (microplastic-free seed coating on the right)

Controling the dust emission of oilseed rape represents another big challenge knowing that most of the time a high quantity of fluency powder is applied at the end of the treatment. It is key for seed companies to ensure a perfect control of dust emission, usually defining targets below the regulatory thresholds. On this topic, novel pesticide seed treatments based on biologicals represent a new hurdle as these formulations are usually more dusty. The dust emissions of seeds treated with Peridiam^® Quality 208 and Peridiam^® Quality 2001 were evaluated with Heubach dustmeter (Figure 4) with two different pesticide recipes, a conventional one based on a fungicide and a insecticide treatments (Recipe 1) and a biologicals recipe based on a biofungicide (Recipe 2). For the conventional recipe, an excellent level of dust control is obtained with the two Peridiam® grades. For the recipe based on a biofungicide, very dusty in comparison to the Recipe 1, Peridiam^® Quality 2001 offers superior control of dust emission than the conventional grade Peridiam^® Quality 208.

Figure 4: Dust emission of oilseeds rape treated with Peridiam^® Quality 208 and Peridiam^® Quality 2001 with two different seed treatment recipes.

In a nutshell, Peridiam^® Quality 2001 offers superior performances as a seed coating for oilseed rape application with remarkable dust reduction performances and a nice and uniform coverage of the treated seeds. It constitutes an excellent choice for the application with new seed-applied biological treatments that will become more popular in the coming years. 

As the application of the microplastic restriction in the EU will converge in terms of timing with the introduction of biological seed treatments, our new range of microplastic-free seed coatings was designed to ensure an excellent compatibility with this new class of actives as well as a high level of performances on seeds.

* About Syensqo

Syensqo is a specialty chemical company with an 8b$ turnover, 13.000 employees located in 30 countries, launched in December 2023 following the Solvay spin-off.

Syensqo’s team of explorers are focused on breakthroughs that advance humanity,– passionately pushing the boundaries of science to find groundbreaking solutions that make a real difference to the planet and the people on it.

Catalysts of Responsible Agriculture

Syensqo’s aim is to foster a world where agriculture thrives for the benefit of people and in harmony with nature.

As enablers of this transformation, it contributes to farming practices that improve resilience and adaptability.

Syensqo’s capabilities, 40+ years of experience and unwavering commitment to excellence enable cutting-edge formulations that facilitate the transition to more sustainable and efficient agriculture.

Science is the compass; inspiring its teams to push the boundaries of chemistry and biology, collaborate to pioneer new technologies, and ensure you have the best tools to navigate the ever-evolving landscape of modern farming.

More info on Syensqo solutions for Seed Care: https://www.syensqo.com/en/brands/peridiam

If you'd  like to share your company's story and solutions or have any promotion demands in AgroPages, please contact Grace Yuan: grace@agropages.com