One approach to safety is to try to minimise risk by reducing the probability
an accident will happen. This will include:
- Regular checks on valves, pipe-work and other equipment
- Constant computerised monitoring of pressures and temperatures
- Automatic "failsafe" systems to shut reactors down if
conditions deteriorate
Procedures like these are, of course, necessary to maximise safety.
The "greener" approach, however, is to look also at the hazard
presented by the materials used, and find safer alternatives where possible.
This may mean using different reactions or using the chemicals in a
different way.
Bio-availability
Potentially toxic materials can only result in actual harm if they are
ingested or absorbed by people and so are able to react within the body
- we would say they are then "bio-available". This is much
more likely if an accident occurs with a volatile liquid or a gas but
is less likely with solids, which are therefore inherently safer. Insoluble
solids are also much safer if they are not in the form of very fine
powders (have a particle size greater than 10µm).
Several common reactions can in fact be carried out in the solid state
simply by grinding the reactants together. The challenge for researchers
is to make this viable on a large scale.
