Chemical analyses have a limited information content

Chemistry is a powerful science and can provide us with a lot of data and information about chemicals present in packaging, those migrating into foods and drinks, those found in human tissues and body fluids, those found in animals and plants, and those found in the environment.

Let us use chemical analyses in the investigation mode, that means comparing something before and after, comparing the composition of packaging with the composition of food kept in that package, or comparing the original raw food stuff with the finished products, etc… In the investigaton mode we can gather additional key informations, such as where, when, how much, for how long. If we need these data for the purpose of monitoring, the results of these investigaations are essential to decide the next actions. But,

Chemical analyses have intrinsic limits.

We are not talking about technical limits (sensitivity, specificity, etc.. ), which are constantly overcome by novel and improved methods and instruments; we are talking about questions that cannot be addressed by chemistry alone and about knowledge that cannot be obtained by chemistry alone.

Let’s step backward and and reexamine some basic notions:

People are potentially exposed to hundreds of chemicals every day. More than 85,000 chemicals are used in consumer products (Goldman and Koduru 2000) and more than 6,000 chemicals are known to be used in FCMs (Oldring et al. 2013).

If exposure is not adequately controlled, chemicals may cause harm to the exposed population. In order to control chemical exposure, we carry out chemical risk assessment, that is the quantification of the risk for health damage in a population as consequence of chemical exposure. To quantify the risk the experts use the following formula:

risk = exposure x hazard

Risk assessment is clearly distinguished from risk management, that is a normative process carried out by regulators. In the risk management, socio-economic considerations are taken into account and weighed against risk estimates. Subsequently, control and prevention measures will be initiated, if necessary. Risk assessment is a science-based process that is usually subdivided in four steps:

a) hazard identification b) dose-response assessment, or hazard quantification, or hazard characterization c) exposure assessment d) risk assessment, or risk characterization

Unwanted chemicals derived from FCM and migrating into foods/drinks include pure chemicals, unwanted reaction products, impurities, metabolites and/or breakdown products. In addition, there is a large number of food contact substances that are known but have not been previously assessed. The evaluation of these substances requires extensive experimental work, as you will see in step 3.3 and step 3.4

To resolve this, efforts have been invested over the past 30 years into developing the threshold concepts. Threshold is based on the assumption that it is possible to define an exposure value below which there is a very low probability of adverse health effects.

The take home message is:

Chemistry alone cannot tell us all that we need to know. The most important piece of information is: what are the potentially negative effects that a population faces when exposed to certain chemicals, at certain (low) doses and for a certain time? Is there a risk?

So we need something else. We will soon show you how analytical chemistry, biology, epidemiology and medicine need to join efforts to assess and comprehend the potential effects of low-dose chemicals on our organism.