Toxicity testing, aromatic

Loibner, A.P., Szolar, O.H.J., Brann, R., and Hirmann, D. Toxicity testing of 16 priority polycyclic aromatic hydrocarbons nsing Lnmistox , Environ. Toxicol Chem., 23(3) 557-564, 2004. 

Toxicity tests on 31 pure hydrocarbons of aromatic, olefin, naphthene, and paraffin series are reported. The hydrocarbons, ranging in boiling point from 176 to 572 F., were representative of those found in petroleum naphthas. The work was done at Ithaca, N. Y., in both greenhouse and field plots. 

The USEPA OPPT cannot design training sets, nor can it measure the toxicity of industrial chemicals directly. The TSCA prescribes that the chemical industry test chemicals for toxicity thus, the OPPT is dependent upon what toxicity data are submitted to the USEPA under the TSCA. The OPPT could design a training set for a (Q)SAR such as fish acute toxicity for aromatic diazoniums, but it does not have the ability to get the chemicals in the training set tested. Thus, some (Q)SARs used by the OPPT have training sets composed of two data, one datum, or no data—just assumptions about intercept, slope, and log Kow at which no toxic effects at saturation will occur. 

See also Carcinogenesis DDT (Dichlorodiphenyl-trichloroethane) Peroxisome Proliferators Polycyclic Aromatic Hydrocarbons (PAHs) Skin Toxicity Testing, Dermal. 

Other groups also used gel filtration exchange to measure middle molecules and perform in vitro toxicity tests (C7, D21). However, many of the middle molecular weight substances isolated by these techniques proved to be much smaller than anticipated. This discrepancy was due to the intrinsic inadequacies of the standard gel filtration techniques for the isolation of middle molecules, as pointed out by Furst et al. (F13) and later by Schoots et al. (S13). These investigators used analytical techniques to demonstrate that middle molecular fractions obtained by gel filtration comprised many low-molecular-weight solutes, such as carbohydrates, amino acids, polyols, aromatic substances, and other UV-absorbing solutes, and also sodium chloride, acetate, phosphate, and sulfate (S10). Thus these fractions do not exclusively represent middle molecules. 

Phenylenediamine reacts with aromatic aldehydes, giving yellow to red Schiff bases (Fig. lb). Most -orcinol depsidones, as well as some -orcinol depsides, give a positive PD test. Aromatic diamines other than p-phenyl-enediamine also react with aromatic aldehydes. Asahina (1934) found that benzidin gives less intensely colored reaction products thanp-phenylenedia-mine. Santesson (1966) compared some diamine reagents and suggested the use of o-dianisidine (OD) as a PD substitue. o-Dianisidine is more sensitive, more stable, and more toxic than PD, but not as corrosive. The color reactions obtained with OD are not always identical with those of PD. 

Commercial PCBs Toxic and Biochemical Effects. PCBs and related halogenated aromatic hydrocarbons ehcit a diverse spectmm of toxic and biochemical responses in laboratory animals dependent on a number of factors including age, sex, species, and strain of the test animal and the dosing regimen (single or multiple) (27—32). In Bobwhite and Japanese quad, the LC q dose for several different commercial PCB preparations ranged from 600 to 30,000 ppm in the diet the LC q values for mink that were fed Aroclors 1242 and 1254 were 8.6 and 6.7 ppm in the diet, respectively (8,28,33). The... 

The behavior of the different amines depends on at least four factors basicity, nucleophilicity, steric hindrance and solvation. In the literature (16), 126 aliphatic and aromatic amines have been classified by a statistical analysis of the data for the following parameters molar mass (mm), refractive index (nD), density (d), boiling point (bp), molar volume, and pKa. On such a premise, a Cartesian co-ordinate graph places the amines in four quadrants (16). In our preliminary tests, amines representative of each quadrant have been investigated, and chosen by consideration of their toxicity, commercial availability and price (Table 1). 

Recent studies, including the use of Microtox and ToxAlert test kits [55,56], were carried out for the determination of the toxicity of some non-ionic surfactants and other compounds (aromatic hydrocarbons, endocrine disruptors) before implementation on raw and treated wastewater, followed by the identification and quantification of polar organic cytotoxic substances for samples with more than 20% inhibition. Furthermore, the study of their contribution to the total toxicity was obtained using sequential solid-phase extraction (SSPE) before liquid chromatography-mass spectrometry (LC-MS) detection. This combined procedure allows one to focus only on samples containing toxic substances. 

One consequence of the uptake of some contaminants is a reduction in the ability of lysosomes to retain the dye Neutral Red. As a consequence, the Neutral Red retention time has been developed as an index of lysosomal membrane fragility and thus of toxicity. The test has been used on the digestive cells involved with intracellular digestion of endocytosed food following administration of organic contaminants, such as polycyclic aromatic hydrocarbons [71]. The phenomenon has been reported many times after exposure to... 

CYP1A1. In humans, of the two members, CYP1A2 is the major player while CYP1A1 is a relatively minor extrahepatic isoform associated with the oxidation of polycyclic aromatic hydrocarbons like benzo[a]pyrene. Similarly, in test rodent species it is responsible for the generation of toxic intermediates and carcinogenic metabolites (10). 

There are indications that pure naphthalene (a constituent of mothballs, which are, by definition, toxic to moths) and alkylnaphthalenes are from three to 10 times more toxic to test animals than are benzene and alkylbenzenes. In addition, and because of the low water solubility of tricyclic and polycyclic (polynuclear) aromatic hydrocarbons (i.e., those aromatic hydrocarbons heavier than naphthalene), these compounds are generally present at very low concentrations in the water-soluble fraction of oil. Therefore, the results of this smdy and others conclude that the soluble aromatics of crude oil (such as benzene, toluene, ethylbenzene, xylenes, and naphthalenes) produce the majority of its toxic effects in the enviromnent. 

EPA Toxic Substances Control Act Manufacturers and processors of the C, aromatic hydrocarbon fraction must test this fraction for the following neurotoxicity, mutagenicity, developmental toxicity, reproductive effects, and oncogenicity Yes EPA 1991a (40 CFR 799.2175) EPA 1987c... 

Factorial designs, in which n chemicals are tested at x dose levels (x treatment groups) have been suggested by the US-EPA (US-EPA 1986) as a statistical approach for risk assessment of chemical mixmres. A 2 factorial design has been used to describe interactions between the carcinogenic activity of five polycyclic aromatic hydrocarbons at two dose levels (Nesnow 1994) and a 5 design to identify nonadditive effects of three chemicals on developmental toxicity at five dose levels (Narotsky et al. 1995). 

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