Toxic properties classification

Has toxic properties that result in classification as a hazardous waste, but specific properties may vary greatly... 

Muscarine is a natural alkaloid that is found in a number of wild mushrooms. Despite the fact that muscarine does not have any therapeutic value, it is of interest because of its expressed toxic properties, which made it one of the first systematically studied cholinomimetic substances. This compound was an underlying classification of cholinergic muscarinic receptors. The action of muscarine is similar to that of acetylcholine on peripheral autonomic effector organs, and atropine is an antagonist to it. Unlike acetylcholine, muscarine does not act on nicotinic receptors. 

A survey of acute oral toxicity, as measured by the 50% lethal dose (LD j) test, demonstrated that of4461 colorants tested, only 44 had an LD-,j< 250 mg kg and that 3669 exhibited practically no acute toxicity (LD > 5 g kg ). The rest fell somewhere between these two levels. The evaluation of these colorants by chemical classification revealed that the most toxic ones were found among the diazo (mostly benzidine derivatives) and the cationic dyes. It is widely known that some general cationic compounds have toxic properties. Pigments and vat dyes by comparison were discovered to have extremely low acute toxicity - presumably due to their insolubility/very low solubility in water and in lipophilic systems. 

Most chemicals are not officially classified in accordance of annex I of Directive 67/548/EEC [3-lj. Indeed, about 30 000 chemicals with production volumes above one toruie per year are placed on the market, but only approx. 2500 substances are Hsted in annex I. The person responsible for placing a product on the market or the producer of the product has the duty of classification, taking the known properties into consideration. Usually, the assessment of the available data is difficult and requires expert knowledge. Especially the classification of the different toxic properties can only be done after an intensive hterature research. The assessment of the different studies is usually quite difficult, especially if investigations have been done which do not meet the guidelines ofaimex Vof the Directive 67/548/EEC [3-1] or the OECD methods. 

The carcinogenic, mutagenic and reproduction toxic properties in the EC classification are, in the jargon used, referred to as cmr properties [14.103a] ... 

Requirements for labelling of containers for supply may differ from those for conveyance. Key features of a supply label are to identify the substance (the chemical name in most cases) and any hazards and safety precuations. In Europe the classification, packaging and labelling of dangerous substances is covered by Directive 67/548/EEC as amended. This requires labels to identify appropriate risk and safety phrases (Tables 12.2 and 12.3) depending upon product properties. A substance is considered dangerous if in Part lA of an approved list or if it exhibits hazardous properties as defined in Schedule 1 for supply, or Schedule 2 for conveyance as shown in Tables 12.4 and 12.5. Substances not tested should be labelled Caution — substance not yet fully tested . Criteria for risk phrases are provided, e.g. as in Table 12.6 for toxic compounds. 

The discovery that, in industrialised societies, diets deficient in fruits and vegetables can effectively double the risk of developing many different types of cancer has focused renewed attention on the beneficial properties of these foods (Block e/a/., 1992 Patterson ef a/., 1990 Southon and Faulks, 2002). As we have seen, plant foods are rich in micronutrients, but they also contain an immense variety of biologically active secondary metabolites providing colour, flavour and natural toxicity to pests and sometimes humans (Johnson et ah, 1994). The chemistry and classification of such substances is still a matter for much research and debate, but this has not prevented attempts to isolate and exploit substances that have variously been termed protective factors , phytoprotectants , phytochemicals and nutraceuticals . Phytochemical compounds include ... 

Furthermore, it has been shown that the time period until ignition occurs, in the Cone calorimeter, is proportional to the inverse of the flame spread rate [16]. The Cone calorimeter can also be used to provide the mass loss rate information required for the simplified classification into categories of toxic hazard [1] quick toxic hazard assessment. Thus, the NBS Cone calorimeter is a very useful tool to overcome some of the disadvantages associated with measuring a single property at a time. 

The C02 transported and stored is generally assumed to be of such purity that it can be judged as a non-toxic and non- or low-corrosive gas. Given these classifications, the properties of the C02 should not impose a risk to prevent transport and storage activities. The processes required to reach these properties will, however, influence the economics of the facility. 

An a priori classification of these various reactions as either toxification or detoxification is simply impossible, since each product from these various pathways may be toxic or not depending on its chemical properties and own products. Furthermore, the biological context plays a critical role [154], yet this role, best viewed as the influence of biological factors on the relative importance of competitive routes of metabolism, is often underplayed by those who venture to make predictions of metabolic outcome. Indeed, in the cascade of intertwined metabolic routes exemplified by haloalkenes, a small difference in pathway selectivity at an early metabolic crossroad may be amplified downstream, giving rise to major differences in relative levels of metabolites and overall toxicity. 

In the chemical safety report, the hazard assessment of a particular substance is based on the data set provided in the technical dossier. This contains substance-specific information on physicochemical properties as well as on toxicological and ecotoxicological hazards. One objective of the hazard assessment is the substance s hazard identification, which comprises the determination of its physicochemical and hazardous properties for the purpose of classification. Concerning human health hazards, both human and nonhuman information is taken into consideration and evaluated with respect to the classification criteria laid down in the Dangerous Substances Directive and in the CLP Regulation, respectively. However, in most cases human data do not exist, so the hazard identification has to be based on data from animal experiments. With respect to teratogenicity, this hazardous property may in principle be detected in the following toxicity studies ... 

The basic idea of the CLH process is the transfer of responsibility for classification and labeling from industrial companies to authorities on a European Community level. In case of active substances in biocidal or plant protection products, all intrinsic properties including physicochemical properties, human health hazards, and environmental hazards are subject to the harmonization. By contrast, in the case of chemicals which are used in other application fields only some specific hazard classes are considered in the CLH procedure. According to Article 36 of the CLP Regulation, these are respiratory sensitization, carcinogenicity, germ cell mutagenicity, and reproductive toxicity. Consequently, these provisions have... 

This volume of the series Medicinal Plants of the World Chemical Constituents, Modern and Traditional Medicinal Uses contains information on 16 plant species and follows the same format as volumes 1 and 2. Some of the plants discussed in volume 3 may be considered controversial in their classification as medicinal. However, the Paracelsian dictum that sola dosis fecit venenum has been appreciated since ancient times, and throughout the ages many highly toxic materials used for lethal purposes have also found applications in modern medicine. It has been recognized that plants contain substances that are either harmful or toxic. However, it is wrong to think that there are plant toxins that are known or that are likely to have adverse effects on any and every form of life. A common feature of most toxic plants is that they are also known for their curative properties, and although they may provide the cure for an individual s disease at one dose, they may cause the death of the same individual at another. 

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