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Acute toxins

Although the 0SHA/NI0SH air sampling scheme has not been applied to acute hazards, it would be useful to illustrate the implications of doing so. Consider exposures to the acute toxin, hydrogen cyanide (HCN). Let us assume that the current exposure limit recommended by NIOSH of 5.0 mg/m3 (18) is used as the PEL and that the AL is one half of this value (2.5 mg/m3). The air concentration of HCN required to produce death in man in 10 min is V lOO mg/m3 (18 >19) or 20 times the PEL. [Pg.440]

The hypothesis to be tested requires an appropriate test statistic. Since acute toxins are being considered here, it is essential to choose a statistical measure that is likely to identify lognormal distributions that potentially produce large values, even if these values are improbable. A sensitive statistic tic must combine both the overall level (mean) and the intrinsic variability (variance). A test statistic with this property is the estimated 95th percentile defined as... [Pg.446]

Chronic toxicity refers to a chemical s ability to inflict systemic damage as a result of repeated exposures over a prolonged time period, to relatively low levels of the chemical. Some chemicals are extremely toxic and are known primarily as acute toxins (e.g., hydrogen cyanide) some are known primarily as chronic toxins (e.g., lead). Other chemicals, such as some chlorinated solvents, can cause either acute or chronic effects. [Pg.504]

Based on this type of reasoning, investigators have divided defensive substances into (1) the acute toxins (qualitative defenses) that are present in very low concentrations in plant tissues and which exert their effects on herbivores by interfering with some basic metabolic process such as transmission of nervous impulses, and (2) digestibility-reducing substances (quantitative defenses) that are present in higher concentrations in plant tissues, that act in the gut of the animal to reduce its ability to utilize its food, particularly proteins, and whose effectiveness increases directly with their concentration (Cates and Rhoades, 1977 Feeny, 1970, 1976 McKey, 1974 Rhoades and Cates, 1976). Qualitative defenses... [Pg.45]

Studies on the toxic effects of DSP toxins in animals were performed mainly after acute toxin administration, and only few studies after repeated OA administration are available. [Pg.239]

Acids, alkalis, and phenols are acute toxins (the effect appears rapidly). Acids and alkalis destroy the skin tissue while phenol rapidly attacks internal body organs. Other absorbed materials can affect the body in a chronic way (the effect becomes visible only after repeated exposures). Personal protective equipment (PPE) is the most widely used means of protection against absorption. Gloves, coveralls, and face shields protect the worker from splash contact with toxic chemicals. However, PPE, if it is not donned properly, is useless for protection. [Pg.63]

Exclamation mark is used to signify irritants, skin sensitizers, acute toxins (harmful), chemicals with narcotic effects, and respiratory tract irritants. While not mandatory under OSHA it will also identify substances hazardous to the ozone. [Pg.39]

Provisions for additional protection for woik with highly hazardous substances like select carcinogens, reproductive toxins, or acute toxins to include ... [Pg.248]

Certainly, in the case of the insecticides, past experience has shown this approach to be successful, with synthetic pyrethroids as the best example. Other commercially useful botanical pesticides include nicotine, pyrethrum, rotenone and several other alkaloids. Similarly, other natural compounds modifying feeding behavior or inhibiting the growth of insect larvae, are considered viable alternatives to acute toxins, for insect control (3). One of the most successful examples so far is Neem, extracted from the seeds of the tree Azadirachta indica. [Pg.162]

Acute toxins can cause severe injury or death as a result of short-term, high-level exposure. Never work alone when using acute toxins. To ensure proper ventilation, use a fume hood. Examples of acute toxins include the following ... [Pg.143]

A large proportion of the plant-derived teratogens are alkaloids. In most cases these teratogenic alkaloids are also acute toxins. Those alkaloids that are teratogenic to livestock are included in a recent review by Roitman and Panter (Roitman and Panter, 1995). This discussion will include information and examples from only two of the 14 classes of alkaloids (steroidal and quinolizidine) which contain teratogens. The reader is referred to the aforementioned reviews to locate information about other alkaloid teratogens. [Pg.20]

Plant toxins which act as hepatotoxins or abortifacients do not act as acute toxins. Their toxicity is of a more subtle, insidious nature with few outward manifestations until shortly before death (hepatotoxins) or abortion (abortifacients). In the case of range animals, the site and degree of exposure of a group of animals will often go unnoticed until an animal succumbs or aborts leaving the rancher with little information about either the toxic source or the location. The mode of action of these toxins dictates their consideration as toxins to humans, particularly in relation to their possible inclusion in herbal medicines and natural home remedies. [Pg.22]


See other pages where Acute toxins is mentioned: [Pg.434]    [Pg.12]    [Pg.187]    [Pg.45]    [Pg.117]    [Pg.42]    [Pg.207]    [Pg.23]    [Pg.306]    [Pg.363]    [Pg.6]    [Pg.246]    [Pg.21]   
See also in sourсe #XX -- [ Pg.434 ]

See also in sourсe #XX -- [ Pg.306 ]




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