Toxicity relative

Table 2. Allethrin Isomers with Their Abundance and Relative Toxicities to Musca. domestica...

Table 4. Relative Toxicity of Substituted Phenyl Diethyl Phosphates...

The relative toxicities of thallium compounds depend on their solubHities and valence states. Soluble univalent thallium compounds, eg, thaHous sulfate, acetate, and carbonate, are especiaHy toxic. They are rapidly and completely absorbed from the gastrointestinal tract, skin peritoneal cavity, and sites of subcutaneous and intramuscular injection. Tb allium is also rapidly absorbed from the mucous membranes of the respiratory tract, mouth, and lungs foHowing inhalation of soluble thallium salts. Insoluble compounds, eg, thaHous sulfide and iodide, are poorly absorbed by any route and are less toxic. 

The classic example of an antiinflammatory dmg is aspirin [50-78-2], acetosahcyflc acid, an effective analgesic for many years. It is well tolerated by the dog and the horse, but is relatively toxic to cats. Under the proper clinical circumstances, it can be used for prolonged therapy in chronic inflammatory diseases such as arthritis. Rimadyl is presently used. 

In general, chi orohydrin s are relatively toxic irritants. They are harmhil if swallowed, inhaled, or absorbed through the skin. They cause irritation to the eyes, skin, mucous membrane, and upper respiratory tract. 

Toxicology. An excellent review of the toxicity and health assessment of ethylene oxide has been compiled (233). Ethylene oxide (EO) can be relatively toxic as both a Hquid and gas. Inhalation of ethylene oxide ia high concentrations may be fatal. Estimates of lethal ethylene oxide inhalation levels in animals depend on the duration of exposure. The reported 4-h LC q values for rats, mice, and dogs are 1460, 835, and 960 ppm, respectively (234). More recent information (235) indicates that the 1-h LC q in rats is approximately 5000 ppm. 

The composition of the vapour in equilibrium with a miscible liquid mixture at any temperature, e.g. on heating during distillation, will be enriched by the more volatile components. The composition of the liquid phase produced on partial condensation will be enriched by the less volatile components. Such fractionation can have implications for safety in tliat tlie flammability and relative toxicity of the mixtures can change significantly. 

Table II. Relative Toxicity of Pyrethrum LD50, and LD75 Levels Experiment A Constituents at LD25, Experiment B ...

Sawicki and Elliott (31) re-examined the insecticidal activity of pyrethrin extracts and its four insecticidal constituents against four strains of houseflies, and checked the relative toxicity of pyrethrins I and II. This work confirmed the earlier results, showing that pyrethrin II was 1.3 to 1.6 times more toxic than pyrethrin I, but that the relative toxicities of pyrethrins I and II against the four strains of flies differed little. Resistance to knockdown but not to killing was associated in these strains with resistance to organophos-phorus and chlorinated insecticides. 

They found that the methods of immobilizing flies during treatment had no effect on the relative toxicity of the pyrethrins. Strong chilling possibly increased the susceptibility of the flies to the pyrethrins, at least during the first 24 hours after treatment, but did not alter the relative toxicities. 

Table III. Relative Toxicity of Four Constituents of Pyrethrum at Six Ratios of Synergist to Active Ingredient...

In general, adding organic groups to the tin appears to lessen the affinity of Pseudomonas 244 for the metal. This may be related to the relative toxicity of the organotln derivatives, as BujSn is the... 

Kerr SH, Brogdon JE. 1959. Relative toxicity to mammals of 40 pesticides. Agricultural Chemicals 14 44-45, 135. 

Figure 2. Relative toxicity (LD50 and LD qq) estimates for actiniid sea anemone toxins upon crabs (Carcimis maenas) and mice. Values for Anemonia sulcata (As) and Anthopleura xanthogrammica (Ax) toxins are from ref. 24 data for Condylactis gigantea and Phyl-lactis flosculifera toxins are unpublished (Kem). The arrows indicate that the real mouse LD q values for Cg II and Pf II must exceed the values indicated in the Ogure. Although insufficient data are presently available to quantitatively define a relationship between mammalian and crustacean toxicity, it seems that there is usually an inverse relationship, which may be approximately defined by the stipple zone.

Human immunodeficiency virus (HIV) is a retrovirus, i.e. its RNA is converted in human cells by the en me reverse transcriptase to DNA which is incorporated into the human genome and is responsible for producing new HIV particles. Zidovudine (azidothymidine, AZT Fig. 5.22F) is a stmctural analogue of thymidine (Fig. 5.22A) and is used to treat AIDS patients. Zidovudine is converted in both infected and uninfected cells to the mono-, di- and eventually triphosphate derivatives. Zidovudine triphosphate, the aetive form, is a potent inhibitor of HIV replication, being mistaken for thymidine by reverse transeriptase. Premature ehain termination of viral DNA ensues. However, AZT is relatively toxic because, as pointed out above, it is converted to the triphosphate by eellular enzymes and is thus also aetivated in uninfected cells. 

In rat liver slices, evidence also supports the roles of QMs in mediating the toxicity of a series of 4-methylphenols.24 The potency correlates with rates of QM formation in the order 2-bromo-4-methylphenol > 4-methylphenol = DMP > TMP > 2-methoxy-4-methylphenol. None of these compounds contain two bulky ortho substituents, so as discussed earlier the corresponding QMs are expected to be highly reactive. The authors suggested that differences in the reactivities of these QMs determine their relative toxic potencies as electron-donating substituents on the ring stabilize the QM and thereby reduce its toxicity (e.g., 2-methoxy-4-methylphenol is less toxic than DMP) and conversely, electron-withdrawing substituents destabilize QMs and enhance toxicity (e.g., 2-bromo-4-methylphenol is more potent than DMP). 

The relative toxicity, especially of the newer compounds, to various pests and species is of practical importance, as are also differences in species tolerance to DDT and other sprays. This is also of direct concern in relation to parasites and predators. There is interest in synergistic action and the effect of spreaders, stickers, and related products. The effect and use of repellents and attractants have received attention. 

Parathion is relatively toxic to insect life (1) as well as to mammals therefore, under conditions of usage it has a favorable ratio. 

In reactions with 0.04 M ethanolic sodium hydroxide at 46° C. the insecticidally more active octachloro isomer, IIA, and the nonachloro compound, III, reacted much more rapidly than the heptachloro compound, I, and the less active octachloro compound, IIB, showed no measurable reaction in 43 hours. In refluxing 1 M ethanolic alkali, the octachloro compound, IIB, is reactive. The relative toxicities of these compounds toward houseflies (14) are given in Table III. Here again there is no correlation between chlo-... 

Different metal species vary in their biological reactivity.98 99 For example, the free ionic form of a metal may act by substituting a cofactor for a vital enzyme. Hydroxylated metal ions have been suggested to bind to the cell surface and alter the net charge of the cell to reduce its viability.101 Because different species may have different effects on biological processes, some species may be more toxic than others. There is a paucity of information in the literature regarding the relative toxicity of different metal species. 

The soil sterilizer metham (sodium methyldithiocarbamale) may act simultaneously as a fungicide, a nematodidde, and an herbicide [4, 5, 30, 41]. Metham itself is relatively toxic (the FD50 is 285 mg/ kg for white mice, and 820 mg/kg for... 

Broderius SJ, Smith LL Jr, Lind DT. 1977. Relative toxicity of free cyanide and dissolved sulfide forms to the fathead minnow (Pimephales promelas). Journal of the Fisheries Research Board of Canada 34 2323-2332. 

Iron Rat Tissue levels and relative toxicity of lead Iron deficiency increases lead absorption and toxicity Six and Goyer 1972... 

Crane CR, Sanders DC, Endecott BR, et al. 1986. Inhalation toxicology VI. Evaluation of the relative toxicity of thermal decomposition products from nine aircraft panel materials. Washington, DC Federal Aviation Administration, Office of Aviation Medicine. DOT/FAA/AM-86/3. 

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