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Green Screen Method Version 2

The Green Screen Version 2.0 Method is DRAFT ONLY AND UNDER DEVELOPMENT.  The contents of this site are not being updated regularly. 

1.  Introduction

2.  Hazard Thresholds

3.  Benchmarks

4.  Guidance and Resources for Assessments

5.  Reference Information for Green Screen Technical Advisory Committee

The Green Screen for Safer Chemicals Version 2.0 (Green Screen) is a method for classifying and benchmarking chemicals based on inherent hazard. Once the overall hazard classification and benchmarking has been established, alternatives can be considered and compared based on the functional use and other considerations (e.g. cost, performance, etc.).  The methodology involves 4 steps:

1. Collect Data & Fill out the Hazard Summary Table: Evaluate the chemical being considered and any significant transformation products that may occur based on feasible end-of-life pathways against the hazard threshold criteria identified in the corresponding Hazard Threshold Tables (listed below with links).   Compile the results of the classification in the Hazard Summary Table. See the guidance section for further information on how to fill out a Hazard Summary Table and to view an an example.

    •  Table 1A Threshold Values for Environmental Toxicity and Fate Endpoints

    •  Table 1B Threshold Values for Human Health Endpoints

    •  Table 1C Threshold Values for Physical/Chemical Endpoints

2. Apply the Benchmarks: Using the Hazard Summary Table, apply the Green Screen Benchmarks to the chemical being considered (and any significant transformation products). The Benchmark for the chemical is based on the more conservative value obtained for either the chemical being considered or the significant transformation products. Please see the guidance section to learn more about the specific benchmarks and how to assign a benchmark to a given chemical using the Hazard Summary Table.  

3. Consider the context: When using the Green Screen, it is important to consider context and to practice responsible risk management. Even chemicals with inherent low hazard can cause harm if used inappropriately (i.e. inhaling too much water!). There are two primary ways that Green Screen Benchmarks can be considered contextually to help drive movement toward the use of safer chemicals -- By comparing chemicals with similar functional uses and by applying a risk management framework that includes exposure and transformations over the life-cycle.

    • When comparing alternatives it is useful to compare chemicals based on their functional use. By comparing chemicals with similar functional uses, one can assume a rough equivalency in exposure. In that situation, direct hazard comparison allows one to identify the option with the lower inherent hazard and presumably lower risk.
    • When identifying greener chemicals, it is also necessary to apply a risk management framework that includes consideration of application, exposure and feasible transformations that may occur over the product life-cycle. (See Guidance p ??.)

 4. Take action. The chemical’s overall benchmark may be helpful in identifying chemicals of high concern, comparing alternatives, identifying important data gaps and identifying greener chemicals. Chemicals of high concern are those that have achieved Benchmark 0 and are recommended as a high priority for substitution based on their inherent hazard and regulatory precedent.

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