Developmental Classification System

Biopharmaceutical Classification System (BCS) and the Developmental Classification System (DCS) and Their Implications... 

In accordance with both the old and the new European classification system teratogenic effects constitute a health hazard but a separate classification for teratogenicity is not provided. Instead, teratogens are classified as developmental toxicants, with developmental toxicity falling within the hazard class of reproductive toxicity. 

Due to the specificity of toxicogenomic signatures, compounds may be classified based on common genes (or pathways) disrupted. In developmental toxicity testing, approaches may be used for classification between (1) toxic and nontoxic exposures and/or (2) classes of chemical compounds. To date, most classification studies have been conducted in alternative developmental systems (i.e. stem cells, zebrafish, whole embryo culture) due to the size of material and experimental groups needed. In a series of studies by... 

The third part. Developmental Psychopathology, delves into detailed disease-specific overviews. Each of the chapters covers issues pertaining to nosology and classification, to genetic determinants, brain systems implicated, environmental influences, and nature-nurture interactions. Neurotransmission and neuromodulation, and hormonal and other developmental influences are addressed and, whenever available, relevant animal models are incorporated into the discussion. The interplay of normative and derailed development is a core concept for these chapters. Of the part s 12 chapters, 9 are devoted to traditionally defined disease categories, and 3 cover the overarching areas of early-life stress, aggression, and affiliative behaviors. 

DOT CLASSIFICATION 2.2 Label Nonflammable Gas, Oxidizer SAFETY PROFILE Human systemic effects by inhalation cough and other pulmonar " changes. Human teratogenic effects by inhalation developmental abnormalities of the fetal cardiovascular system. Mutation data reported. Not toxic as gas. In liquid form it can cause severe burns and tissue damage on contact with the skin due to extreme cold. 

The classification of category 1, 2, or 3 cannot take into account the extremely variable potential for developmental toxicity. Therefore, in some countries efforts are being made to implement a better differentiation system. The German MAK commission, for example, classifies the developmental toxic substances in 3 additional groups on the basis of the occupational exposure levels (OEL). A classification has to be done if a developmental toxic effect can occur at the concentration of the established occupational exposure level. As a consequence of the fact that the concentration of the OEL is mostly much lower than the lowest effect concentration (LOEL) for developmental toxicity, many substances classified as developmental toxic substances do not show this property at the OEL. Figure 3.12 shows some selected chemicals which do not cause concern at the OEL. 

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