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Chemical analyses have limits

In this article we will show you some technical facts. Don’t be afraid, knowing a bit of technical facts will help you comprehend all the rest.

In this article we will show you some technical facts. Don’t be afraid, knowing a bit of techniques will help you comprehend all the rest.

Analytical chemistry is the science that recognizes and distinguishes thousands of chemicals, alone or in mixes. With the right equipments and methods, an experienced chemist can tell us what is present in a sample (food, drink, package, soil, air, urine, other body fluids, etc…) and how much is present (from zero to some amounts). In parallel other sciences, such as Biology, Epidemiology and Medicine, join efforts to comprehend the possible effects of low-dose chemicals on our organism. These is the subject of week 2.

The chemicals that are present in a Food Contact Materials (FCM), but that have not been specifically added for some purpose – for instance due the production process – are called not intentionally added substances, or NIAS.

Chemicals that are initially present in FCM but then are detected in foods and drinks are called migrating chemicals. Migration depends on various factors:

  • The physical-chemical properties of the migrant, of the FCM and of the food (for instance fat content)
  • The temperature
  • The storage time
  • The size of the packaging in proportion to the food volume

Chemical risk assessment is the quantification of the risk for health damage occurring in a population due to chemical exposure. Chemical risk assessment has four phases: a) hazard identification, b) dose-response assessment (or: hazard quantification, hazard characterization), c) exposure assessment, d) risk assessment (or risk characterization).

People are 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 FCM.

Threshold for concern. This concept is subdivided in Threshold of Toxicological Concern (TTC) and Threshold of Regulation (TOR). These are risk assessment methods that assign human exposure thresholds to substances with known chemical structure but unknown toxicity. Unwanted chemicals include unwanted reaction products, impurities, metabolites and/or breakdown products. Furthermore, there is a large number of food contact substances that are known but have not bees assessed. The evaluation of these substances requires extensive cellular and biological data of toxicological type.

Biomonitoring is the assesment of what levels of a specific chemical can be found in human bodies, in particular in human biological fluids. This information is very important for risk assessment. Chemicals are present in everyday objects: products like toothpaste, carpets, electronics and cosmetic products can be sources of chemicals that people are exposed to.

Adverse outcome pathway describes the sequence of events linking initial molecular perturbations to adverse outcomes in organisms and populations; this framework supports the use of wide-range animal-free toxicity testing methods in regulatory decision making.

Regulatory toxicology is constantly asked to assess an ever increasing number of chemicals in accordance with legislative mandates. At the same time, there is a growing pressure to reduce the use of animals in testing, but also the time and costs required to perform chemical toxicity testing.

A solution proposed by the U.S. National Research Council in 2007 is to reduce the reliance on the traditional whole animal-based descriptive toxicity testing. Instead, a larger emphasis should be placed on the use of mechanistic (pathway-based) data. This novel testing paradigm should incorporate an expanded array of computational in silico methods as well as animal-free in vitro assays, preferably those in which testing is performed with material of human origin.

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Consumer and Environmental Safety: Food Packaging and Kitchenware

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