Safety

A shark in the water is a strong hazard. But if standing safely ashore, there is no exposure to the hazard – as a result, there is no risk. If standing in the water, you're directly exposed to the hazard – accordingly, there is a risk.

So, what does that mean in the context of environmental safety?

To understand the potential risk of using a specific crop protection product, we need to understand the intrinsic hazard of a substance for a wide range of organisms, from bees to fish to birds – and we need to know what the potential exposure levels of these organisms in the environment could be.

Effect Level Testing

Toxicity to different species is tested.

Exposure Level Testing

Laboratory and field experiments as well as model calculations and real-world monitoring programs are used to investigate and understand the distribution of substances between the different environmental compartments (soil, groundwater, surface water, air), how they degrade and which metabolites they form. All identified metabolites are investigated in the same way to understand their environmental behavior, too.

Combining the results from effect and exposure levels testing, we can quantify the environmental risk.

To get all this information, we evaluate and test in several areas.

Ecotox

The science of ecotoxicology has evolved over the past 50 years and — as indicated by the name — combines knowledge and techniques from both ecology and toxicology.

How toxic is the compound to the non-target organisms?

Testing the potential impact of a crop protection product on non-target organisms is very important, as one of our key goals is to protect the organisms that are not targeted by the crop protection product.

Environmental Fate

To be able to quantify the exposure of all the organisms we do not want to harm, we need to understand what happens to a substance when it is released in the environment.

Exposure Modelling

Based on our understanding of the environmental fate, (the degradation, metabolism and mobility), of the compound, and its use pattern, we can predict the concentrations that must be expected in the different environmental compartments when the compound is applied by the farmer. These so-called PEC values (Predicted Environmental Concentrations) are calculated with established and validated scientific models that are approved by regulatory authorities.

The model calculations use a range of soil and weather conditions that are representative for agricultural areas across Europe, combined with information on application regime, application rate, application timing, number of applications, and the crop to which a product will be applied. This allows us to predict concentrations of the active substance and its metabolites:

• in soil after the compound is applied on the field
• in water and sediment after exposure via spray drift, drainage or run-off.
• in groundwater after leaching through the soil

The model parameters are set so that realistic worst-case concentrations are calculated, which will generally not be exceeded under real-world conditions.

If the predicted concentrations show a potential risk, mitigation measures are mandatory to reduce the exposure. In such a case, the models are used to predict the reduction of exposure for a refined risk assessment. You can learn more about mitigation further down in the scroll-story.

Environmental Safety Assessment

Based on the knowledge about ecotoxicology, environmental fate, and environmental exposure, we conduct an environmental safety assessment:

Do the expected concentrations in the environment pose an unacceptable risk to non-target organisms?

By comparing information about exposure levels causing effects and predicted concentrations in the environment, a conclusion about potential risk is reached. Assessment and calculation schemes vary all over the world – but these basic principles are the same. So, let’s have a look at Europe as an example – what happens in a basic risk assessment?

The "toxicity-exposure-ratio" indicates the environmental safety margin.

Implementing the Environmental Safety Assessment 

If a compound passes the environmental safety assessment, it is clear that it can be used without unacceptable effects to the environment. However, this does not mean it can be used in any possible way – the environment safety assessment also indicates the conditions of a safe use. Typical conditions would be that the compound must only be applied at certain times (e.g. not during flowering), only at certain maximum rates, or only in a certain agricultural context. Therefore, after completion of the safety assessment, there are several more steps to define these use conditions and to make sure that they are fulfilled in practice.

Mitigation Measures

Based on the results of our research, we devise measures to control (eliminate or reduce) an unintended impact of our products on the environment. There is wide range of such mitigation measures for all routes of exposure and for all risk assessments. For example, a simple but efficient mitigation measure to eliminate the exposure of bees is the restriction that a compound must not be sprayed while the crop is flowering. We confirm the efficiency of such measures with experimental studies and modelling, which allows the authorities to evaluate during the registration process their appropriateness. The best-known examples of mitigation options are those that reduce or eliminate exposure of areas around the treated field:

Drift-reducing nozzles

Spray drift is the movement of spray droplets to the environment in the vicinity of the application area. Special nozzles can reduce this drift significantly.

No-spray buffer zones

No-spray buffer zones reduce spray drift to neighboring areas, including water bodies. For this mitigation measure, the farmer ensures that a certain margin remains untreated. This could be a strip of crop that is not sprayed, or an uncropped strip between the crop and the surrounding area.

Run-off buffers

A run-off buffer is an area that acts as a cushion between the field that plant protection products were applied to and the nature in the surrounding area. It helps to prevent potential run-off from reaching the environment and non-target organisms.

International working groups are constantly reviewing the current state of scientific knowledge, technology, and agricultural practice. Based on this, they propose new or review existing mitigation measures. You can find examples here: 

• TOPPS Water Protection
• E-book: Mitigating the Risks of Plant Protection Products in the Environment: MAgPIE

Product Label

Each product has a product label that not only specifies details of the product itself, but also explains how it must and must not be used by the farmer. The product label is prescribed by the regulatory authority as part of the product authorization, and is based on their evaluation of all available data, including the outcome of the environmental safety assessment.

The instructions on the product label ensure that the product is used in the right amount, at the right time, in the right areas and on the right parts of the crop. The product label also reflects the conditions of use of the product that are safe, based on the detailed safety assessments described above. In this context, the product label also specifies the mitigation measures that must be applied, such as keeping a certain distance between the treated area and neighboring water bodies, using drift-reducing nozzles, or incorporating the product into soil after application.

Additionally, the label states how the product and the container should be disposed of correctly. Thus, if applied accordingly, the potential impact on the environment and the non-target organisms can be reduced significantly. The farmer’s compliance with the label instructions is ensured by random audits that are regularly carried out by authorities. The use of plant protection products must be extensively documented by the farmer to support these audits.

Product Stewardship

It is the role of authorities to ensure legal compliance of farmers. It is vitally important that farmers get the right training and good advice on how to handle plant protection products. This is the role of our stewardship experts who work directly with the farmers or in collaboration with the official farm advisory services.

They give practical advice in different areas, but specifically promote best management practices (BMPs) with regard to the environmental safety of our products. These environmental BMPs are based on one hand on generic research projects, such as TOPPS Water Protection or MAgPIE, and on the other hand use the thorough understanding of our compounds and the results of our detailed environmental safety assessments.

Is environmental safety necessary to get a registration?

The registration processes for active substances and products ensure that all parts of the environmental risk assessment are evaluated by independent authorities all over the world – in Europe, for example, this is done both at EU and Member State level.

A product is registered and can be sold on the market only if the environmental safety assessment concludes “no unacceptable effects” for all areas, meaning that the product can safely be used.

Applying Global Safety Standards

The regulatory requirements and safety standards in different parts of world are not completely harmonized. While all experimental studies are done according to globally harmonized OECD guidelines, the exact set of studies requested, and their interpretation can differ. On one hand this reflects different environmental and agronomical conditions, e.g. when effect studies with specific local species are requested. On the other hand, authorities may set safety priorities differently. One example is the leaching assessment, which in the U.S. and China is based on the protection of groundwater as a source of drinking water, whereas in Europe the protection goal is to keep groundwater free of anthropogenic compounds. Another example is the protection of endangered species, which in the U.S. is addressed by a specific safety assessment, whereas in Europe this is considered to be covered by the applied safety factors.

How is Bayer dealing with the different regulatory requirements and safety standards in different parts of world? 

We aim to apply consistent and transparent safety standards globally. All safety studies are conducted according to experimental guidelines that are globally established by OECD and are done under the strict quality assurance regulation of Good Laboratory Practice (GLP). This results in one global data set for each compound. In addition, there can be region-specific data, e.g. monitoring data under local environmental and agronomic conditions, or studies with local species, which are generated under the same high-quality standards, but may only be applicable to the specific region.