Module 14 2022

21/03/2022

Threshold of Toxicological Concern (TTC)

Cramer Class

Description

TTC (µg/day*)

I

Substances of simple chemical structure with known metabolic pathways and innocuous end products which suggest a low order of oral toxicity. Substances that are intermediate. They possess structures that are less innocuous than those in Class 1 but they do not contain structural features that are suggestive of toxicity like those in Class 3. Substances with chemical structures that permit no strong initial impression of safety and may even suggest a significant toxicity.

1,800 (30 µg/kg bw/d)

II

540 (9 µg/kg bw/d)

III

90 (1.5 µg/kg bw/d)

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Biological Evaluation

Toxicity Endpoints • Cytotoxicity

– Cell culture methods

• Delayed-Type Hypersensitivity - Contact sensitization

• Irritation - Eye, skin, mucous membrane, intracutaneous

• Pyrogenicity testing

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