Maximum allowable toxicant concentration

Maximum allowable toxicant concentrations (MATC) of cadmium to sensitive species of freshwater teleosts... 

Table 1.4 Maximum Allowable Toxicant Concentrations (MATC)... 

Table 8.7 Release amount (tonnes/year) from PRTR data and the comparison between actual concentration in environment and maximum allowable toxic concentration (MATC) concerning LAS, AE, DHTDMAC and AO... 

Application factor Number used to estimate concentration of a substance or chemical that will not produce significant adverse effects to a population during chronic exposure. The factor is based on the formula application factor = maximum allowable toxicant concentration (MATC) (96 - h LC50)... 

MATC — Maximum allowable toxicant concentration determined by graphical or statistical methods. 

The overall purpose of multiple comparisons is determination of the MATC. The lowest concentration at which an effect is detected is the statistically determined lowest observed effect concentration. The concentration that demonstrates no difference from the control is the no-observed effects concentration (NOEC). The maximum allowable toxicant concentration is generally reported as LOEC > MATC > NOEC. The most sensitive endpoint is generally used for this estimation. Perhaps the greatest difficulty in estimating endpoints such as the NOEC and LOEC is their dependence upon the... 

The toxicity requirements are established per type of industry, in terms of the maximum number of times the effluents needs to be diluted to produce a no observed effect concentration (NOEC), defined as Gf for fish, Gd for daphnia, Ga for algae, and G1 for luminescent bacteria. Testing is limited to the exposure to only the appropriate Gx level, which should not produce any observed effect [the G-value corresponds with the dilution of the effluent, expressed as the lowest dilution factor (1,2,4,...) causing less than 10% mortality]. The level of maximum allowable toxicity per industrial branch is based on the level that is considered to be attainable with state-of-the-art process and/or treatment technology. Violating the toxicity requirements results in a levy, which makes state-of-the-art compliance a more economic option [12]. 

One of the most notorious cases of industrial disaster took place in 1984 in Bhopal, India. A plant with a license from the Union Carbide company was making methyl isocyanate (MIC), CH3NCO, which is an intermediate for the manufacture of pesticides. MIC boils at 39 °C, and the vapor density is heavier than air and very toxic by inhalation and skin absorption. The maximum allowable air concentration is 0.02 ppm by volume over 8 h. MIC also reacts with water and produces heat, which must be removed to prevent boiling over. On that day in 1984, the cooling system failed during... 

The maximum allowable working concentration of the solvent in air to which employees may be exposed is regulated by law. Solvents with small toxic potential and health risk have high exposure values. The toxicity and other stability and reactivity aspects are important in terms of environmental relevance, e.g. the amount of solvent that is permitted to be vented into the atmosphere. As such the working concentration of the solvent has an impact on the investment in and operational costs of the solvent recovery system. It determines whether the process needs official permission and to what extent regular inspections are necessary. If the amount of solvent to be vented is not restricted this simplifies very much the design of the whole process, as the different steps do not need to be sealed completely. 

Elemental fluorine and the fluoride ion are highly toxic. The free element has a characteristic pungent odor, detectable in concentrations as low as 20 ppb, which is below the safe working level. The recommended maximum allowable concentration for a daily 8-hour time-weighted exposure is 1 ppm. 

The maximum permissible body burden for ingested polonium is only 0.03 microcuries, which represents a particle weighing only 6.8 x IO-12 g. Weight for weight it is about 2.5 x lOii times as toxic as hydrocyanic acid. The maximum allowable concentration for soluble polonium compounds in air is about 2 x lO-ii microcuries/cnu. 

Health and Safety Factors. Sulfur hexafluoride is a nonflammable, relatively unreactive gas that has been described as physiologically inert (54). The current OSHA standard maximum allowable concentration for human exposure in air is 6000 mg/m (1000 ppm) TWA (55). The Underwriters Laboratories classification is Toxicity Group VI. It should be noted, however, that breakdown products of SF, produced by electrical decomposition of the gas, are toxic. If SF is exposed to electrical arcing, provision should be made to absorb the toxic components by passing the gas over activated alumina, soda-lime, or molecular sieves (qv) (56). 

Toxicity. Sulfur tetrafluoride has an inhalation toxicity comparable to phosgene. The current OSHA standard maximum allowable concentration for human exposure in air is 0.4 mg/m (TWA) (54). On exposure to moisture, eg, on the surface of skin, sulfur tetrafluoride Hberates hydrofluoric acid and care must be taken to avoid bums. One case of accidental exposure of electrical workers to decomposed SF gas containing SF has been cited (108). 

Health nd Safety Factors. The mononitrochlorobenzenes are toxic substances which may be absorbed through the skin and lungs giving rise to methemoglobin. Their toxicity is about the same as or greater than that of nitrobenzene. The para isomer is less toxic than the ortho isomer, and the maximum allowable concentration that has been adopted for -nitrochlorobenzene is 1 mg/m (0.1 ppm) (6). The mononitrochlorobenzenes are moderate fire hazards when exposed to heat or flame. They ate classified by the ICC as Class-B poisons. The same handling precautions should be used for these compounds as are used for nitrobenzene. 

Health and Safety Factors. The toxic effects of the mononitrotoluenes are similar to but less pronounced than those described for nitrobenzene. The maximum allowable concentration for the mononitrotoluenes is 2 ppm (11 mg/m ) (6). Mononitrotoluenes are low grade methemoglobin formers (4) and may be absorbed through the skin and respiratory tract. The toxicity of alkyl nitrobenzenes decreases with an increasing... 

Toxicological Information. The toxicity of the higher olefins is considered to be virtually the same as that of the homologous paraffin compounds. Based on this analogy, the suggested maximum allowable concentration in air is 500 ppm. Animal toxicity studies for hexene, octene, decene, and dodecene have shown Httle or no toxic effect except under severe inhalation conditions. The inhalation LD q for 1-hexene is 33,400 ppm for these olefins both LD q (oral) and LD q (dermal) are >10 g/kg. 

Toxicity information Toxic hazard rating Hygiene standard (e.g. OLE, TLV) Maximum allowable concentration (MAC) Lethal concentration (LC50) Lethal dose (LD50) ... 

To circumvent some of the above-mentioned drawbacks of sulfur-based mercury chemodosimeters, a system based on the alkyne oxymercuration of 58 has been developed (Fig. 22) [146]. 58 shows high selectivity, a limit of detection of ca. 8 ppm, resistance against strong oxidants, and a positive reaction even in the presence of cysteine, which is known to form stable mercury complexes and is used for the extraction of mercury from tissue samples. Another metal that is well-known for its catalytic ability is palladium, catalyzing different reactions depending on its oxidation state. Since this metal is toxic, assessment of the maximum allowable concentration of Pd in consumer products such as pharmaceuticals requires highly sensitive and selective detection schemes. For this purpose, indicator 60 was conceived to undergo allylic oxidative insertion to the fluorescein... 

SC Bureau Air Qual. 1998. Toxic air pollutants with maximum allowable concentrations. South Carolina Bureau of Air Quality, Department of Health and Environmental Control. 24A SC Code Ann. Regs. 61-62.5 Standard 8. 

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