The target is to have substances and formulations which, ideally:

• HAVE THE NECESSARY PROPERTIES WHEN USED
• ARE NOT HAZARDOUS AND PRESENT NEGLIGIBLE RISK
• REQUIRE THE MINIMUM OF ANIMAL TESTING FOR REGULATORY COMPLIANCE
• USE SUSTAINABLE MANUFACTURING
• DO NOT GENERATE WASTE
• ARE RECYCLABLE
• ARE BIO-BASED

Such a list is the easy part we have all heard before. Solutions? See Strategy for Existing Substances. We want to bridge the gap between the definition of a business’s needs and real action to achieve it.

We can put together small teams which can address all these topics. Green Chemical Design Limited’s specific input is

• Examine existing substances that might not be the best in effects but are less hazardous and can be redeveloped
• To look for such ‘re-born’ alternatives, and especially mixtures, which have robust compliance data
• To seek biodegradable or natural substances
• To engage with predictive toxicology

Examples in our current work:

• Substitution of toxic flame retardant
• Substitution of unacceptable chlorinated solvents
• Substitution of polar solvents by safer ones

It is necessary to develop molecular descriptors that can be used to understand hazard and desired properties simultaneously 

The understanding of hazard and desired properties simultaneously, which requires the ability to find molecular descriptors that can define both performance and hazard. 

By putting these properties into a common ‘language’ synergy between the two becomes possible. 

Too often, good performance and hazard assessment are seen as enemies. We know that they can work together. 

We know it is not easy, but this is the right way forward, in line with current global trends.

Examples in current work:

• Use of the Hansen Solubility parameters to describe adverse effects
• Polymers as low bioavailability substances
• New approaches for anti-oxidants (still in planning stage)

An important part of the work GCD does is developing new tools and methodologies for the future that not only help raise chemistry to a more substainable level but also makes it quicker, easier and cheaper for businesses to achieve the necessary standards that the modern world and coming age of chemistry demands.

Here is our latest contribution in this vein:

SCIENTIFIC REPORT

Hansen Solubility Parameters as descriptors of adverse persistence and bioaccumulation properties of substances. Part 1: Overview

1. Executive Summary

This report is intended for anyone interested in regulation of persistent and bioaccumulative chemicals, from discovery chemists through to regulators. Hansen Solubility Parameters (HSP) are highly relevant to persistence, bioaccumulation, and toxicity (PBT) assessment. HSP describe the nature and strength of intermolecular forces, which are the fundamental basis of understanding chemical interactions.

The emphasis in this report is, for simplicity, on the “legacy pollutants” and analogues in comparison to a set of around 9700 substances.

Comparison to methods of screening based on measurement of bioconcentration and stability is made. HSP gives insights into the bioaccumulation process. HSP has a sound basis in chemical thermodynamics, which gives weight to the new insights in the study of PBT issues. HSP can be determined very easily and could be a much better initial screen than the current methods. There may be a case that some substances should be re-examined in respect of PBT. However, it is unlikely that the regulatory authorities will move away from the present criteria.

The strongest benefit of the use of HSP over study of bioconcentration factor (BCF) is that these parameters have been utilised in many research and development programmes relating to technical performance. Bringing the environmental and performance themes together, it can be stated clearly that there are regions of HSP space that are best avoided by chemistry researchers, due to the risk of a substance having as-yet-undiscovered adverse PBT properties. Adverse properties and desired properties can be examined using the same rrmolecular descriptors. This benefit does not apply to screening based on BCF.

View / Download the Full Report