Sunday, December 05, 2004

Do we have time for REACH?

REACH is the European Unions new program for registration, evaluation, and analysis of chemicals. The aim is to make our life safer.

Currently more than 100.000 chemicals are in use in our society. Some in quantities as small as 1 kilogram per year and others in quantities as large as millions of tons per year. Yet they are all in principle subject to REACH.

While we are waiting for REACH to register, evaluate and analyse the many chemicals we will have spills, accidents and even disasters. Even by optimistic estimates it will take decades to perform the work required by REACH, and I don't think we can afford to wait for this.
For more than 10 years the U.S. National Research Council in collaboration with the U.S. National Academy of Science have been working on the creation of scientifically based emergency exporsure limits for use in emergency situations. This effort defince exposure limites for 10 min., 30 min., 1 hour, 4 hours and 8 hours, i.e. a workday and for three different consequences: discomfort, reduced ability to escape and life threatening. When the work started a list of more than 400 priority chemicals out of the more than 100.000 in use was created in consultations between industry, government and academia. After more than 10 years work Acute Exposure Guideline Levels (AEGLs) have been proposed for a little more than 100 chemicals, and of these only a fraction are finalized. Can we afford to wait for this?

I don't believe so, and so do others. Therefore we have TEELs or Temporary Emergency Exposure Limits similar to Emergency Response Planning Guidelines. All, i.e. AEGL's, TEEL's and ERPG's are based on available information about the toxicity of the chemical and some groups interpretation of this information. But can we do better than this?

The standard operating procedure establish by the NRC for the establishment of AEGL's is a step in the right direction, but in my view it does not cover the needs. What about limits for new compounds developed during research aimed at creating new and more effective ways to treath illnesses such as Cancer or AIDS?

In my view is necessary to develop an approach to the establishment of exposure limits, which reflect the amount of information available during e.g. new drug synthesis projects. During the initial phases of such projects what is known is basically the structure of the chemical. Therefore the establishment of exposure limits for a large number of chemicals should be based on the structure of the chemicals.

In chemical engineering methods for prediciton of physical and chemical properties based on the structure of chemicals are well established. Such methods are called group contribution methods because of the way they e.g. predict boiling points and critical points based on the groups that make up a molecule. In this context groups can be viewed as the LEGO blocks of nature.

A group contribution approach to the establishment of exposure limits properly could be developed within one or two Ph.D.-projects in less than five years. This would significantly shorten the time needed to establish exposure limits for the many chemicals we already use on a daily basis.

With the ability of group contribution approaches to be based on screened experimental data for a limited number of chemicals we can use the exposure limits established by the NRC as a basis for initial models. These models could be refined as more experimental data are screened and the ability to use such models to predict properties of similar models is well known within the chemical engineering community.

Then what are we waiting on? Just salary for one or two Ph.D.-students!

Den Gamle Have Fornyer Sig

Den gamle have, som har ligget hvor den ligger i Københavns centrum i længere tid end de fleste omkringliggende bygninger, fornyer sig med spændende tiltag, som rutchebanen Dæmonen og en kombineret forlystelse og restaurant med et tema fra 1000 år siden. Og så skal hun selvfølgelig kanøfles!
Jeg skriver selvfølgelig om Tivoli i Københavns centrum. Naboerne kan ikke lide alle resultaterne af Tivolis fornyelse, så de vil have en lokalplan for Tivoli, så den gamle have ikke længere kan forny sig uden politisk kontrol. Det ligner noget man ser i en helt anden industri, nemlig den kemiske industri.
Overalt i verden finder man kemisk industri under press fra naboerne. Glemt er det, at naboer er kommet til efter industrien. Det er selvfølgelig i industriens interesse, at have et godt forhold til sine naboer ligesom det er i Tivolis interesse, at naboerne også fremover vil betragte den gamle have som en dejligt åndehul i en fortravlet storby. Når det så alligevel går galt, så er årsagen nok snarest lokalpolitikeres ønske om at profilere sig i medierne uden klart at fortælle hvad formålet med deres nye 'sag' egentligt er set fra et samfundsperspektiv.