DOZN™ – A Quantitative Green Chemistry Evaluator

[ACSGCI]

Contributed by Samy Ponnusamy, Ph.D., Fellow, Green Chemistry, MilliporeSigma; and Jeffrey Whitford, Head of Corporate Responsibility and Branding, MilliporeSigma

Summary: MilliporeSigma created a unique, web-based greener alternative scoring matrix, also known as DOZN^™: a quantitative green chemistry evaluator based on the 12 principles of green chemistry. The 12 principles of green chemistry provide a framework for learning about green chemistry and designing or improving materials, products, processes and systems. DOZN^™ scores products based on metrics for each principle and aggregates the principle scores to derive a final aggregate score. The system calculates scores based on manufacturing inputs, Globally Harmonized System (GHS) and Safety Data Sheet (SDS) information, which provide a green score for each substance. DOZN^™ is flexible enough to encompass the diverse portfolio of products, ranging from chemistry to biology-based products. The DOZN^™ system has also been verified and validated by a third party to ensure best practices are applied, and a peer reviewed paper has been published on it recently. This new greener chemistry initiative offers customers an increased breadth of greener alternative products with confirmatory documentation to validate greener characteristics.

Introduction: Green chemistry is the concept of developing chemical products and processes that minimize the use and generation of hazardous substances, reduce waste, and reduce demand on diminishing resources. Paul Anastas and John Warner developed the foundation that has served as the global framework of green chemistry. That framework proposes 12 complementary principles around resource efficiency and risk (human health and environmental) minimization and targeting a life-cycle perspective (e.g., raw materials extraction, chemical production, and end-of-life bioaccumulation and biodegradation). Ultimately, these 12 principles were adopted by American Chemical Society (ACS) Green Chemistry Institute (GCI).

The 12 principles are only conceptual and do not provide a quantitative framework. While various approaches to quantifying greener processes and products have been proposed, there is no unifying set of metrics in place. After a review of the current state of green chemistry methods, MilliporeSigma developed DOZN^™, a quantitative green chemistry evaluator, and leveraged generally accepted industry practices.

Quantitative Green Chemistry Evaluator:

The design objectives developed by MilliporeSigma industrial chemists included the following:

1. Allow for direct comparison between alternative chemicals considered for the same application as well as direct comparison between alternative synthesis manufacturing processes considered for the same chemical product.
2. Allow transparent comparison against each of the 12 principles and for each of the three major stewardship categories: resource efficiency, human health and environmental hazard, and energy use.
3. Provide sufficient flexibility to apply to the diverse product portfolio.
4. Be inexpensive to implement by utilizing readily available data.
5. Be based on generally accepted industry practices when available.
6. Be easy to communicate the method and results to customers.

Considering these guiding elements, we investigated and designed an approach to evaluate and score chemical products and processes on each of the 12 principles.

Categories: DOZN^™ groups the 12 principles into like categories, allowing for a focus on overarching green chemistry categories of hazard, resource use and energy efficiency. These category groupings and scores are shown in Table 1:

• Improved resource use
• Increased energy efficiency
• Reduced human and environmental hazards

Greener Alternatives Example Results:

Table 1

Category and Related Principles	Old 1-Aminobenzotriazole Process	Re-engineered – 1-Aminobenzotriazole Process
	Principle Score	Principle Score
Improved Resource Use
Principle 1: Prevention	2701	1042
Principle 2: Atom Economy	933	345
Principle 7: Use of Renewable Feedstock	933	345
Principle 8: Reduce Derivatives	0.0	0.0
Principle 9: Catalysis	0.5	1.0
Principle 11: Real-Time Analysis for Pollution Prevention	1.0	1.0
Increased Energy Efficiency
Principle 6: Design for Energy Efficiency	3282	1322
Reduced Human and Environmental Hazards
Principle 3: Less Hazardous Chemical Synthesis	3358	1455
Principle 4: Designing Safer Chemicals	5.0	5.0
Principle 5: Safer Solvents and Auxiliaries	2245	1252
Principle 10: Design for Degradation	0.0	0.0
Principle 12: Inherently Safer Chemistry for Accident Prevention	2516	220
Aggregate Score*	100	44

*Aggregate Score is calculated by averaging each category’s scores and summing three category scores to get the single score. Then this will be further normalized (divided by 50) to get an aggregate score from zero to 100 scales (zero being the most desired).

The GCM is advantageous over existing approaches because it provides metrics that are (1) inexpensive to implement with readily available data, (2) based on generally accepted industry practices when available, and (3) easy to communicate, both method and results, to customers. Sustainability programs that implement the proposed approach should anticipate the following benefits:

• Measurement: Ability to use on-hand data sources or establish straightforward data collection programs
• Calculations: Ability to utilize well-defined metrics to calculate the benefits of the 12 principles of green chemistry
• Communication: Ability to transparently communicate greener alternatives to customers

Based on the feedback from customers, MilliporeSigma is currently working on expanding DOZN^™ system (DOZN^™ 2.0) so customers can screen their products/processes to get DOZN^™ scores. This would help our customers select the greener products for their research/manufacturing to promote sustainability.

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