The Threshold of Toxicological Concern (TTC) concept: Development and regulatory applications

The report describes the development and provides a scientific evaluation of the Threshold of Toxicological Concern (TTC) concept which is based on the assumption that exposure to a chemical below a certain low level – a level which is dependant of the chemical structure of the chemical – is considered to be of negligible concern in relation to health. The advantage with this concept is that a risk assessment of a specific chemical can be done without having specific data on the chemical. Based on the chemical structure the chemical is placed within a chemical group for which a TTC-value has been derived and it can from this be assessed whether an actual exposure is above or below the level of toxicological concern. The report also discuss the possible future use of the TTC-concept and how it can be applied in risk management of chemicals and chemical pollutants.

Abstract in Danish:
Rapporten gennemgår udviklingen og en videnskabelig vurdering af konceptet “Threshold of Toxicological Concern” (TTC) som bygger på den antagelse at der for forskellige grupper af kemiske stoffer kan angives et nedre eksponeringsniveau hvorunder stofferne ikke anses at give anledning til sundhedsmæssig bekymring. Fordelen ved konceptet er at man kan foretage en risikovurdering af et konkret stof selvom man ikke har konkrete toksikologiske data på stoffet, men ud fra indplaceringen af stoffet baseret på dets kemiske struktur i et TTC-system alligevel vurdere hvorvidt en given eksponering giver anledning til bekymring. Rapporten diskuterer på hvilken måde TTC-konceptet fremover kan anvendes i forbindelse med risikohåndtering af kemikalier og kemiske forureninger.