Allowable Concentration MAC

The term MAC is used widely, for example, in the Netherlands and Germany as well as the former Soviet Union and Central and Eastern European countries (IPGS 1996). 

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One of perspective development trends of methods of heavy metals contents reification in natural waters is the creation of selective and express test-method with a possibility of detection at a level and above than maximum allowable concentrations (MAC) of metals - toxiferous. 

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

Maximum allowable concentration (MAC) An old American definition used before the term TLV came into use (the term is still used in Germany). See Threshold limit value (TLV). 

Maximum Allowable Concentration (MAC) Exposure concentration not to be exceeded under any circumstances. 

All three gases are of particular concern for human health reasons. The TLV (8-hour average) for carbon monoxide is 5.5 mg/M, and the National Ambient Air Quality Standard (NAAQS) is 10 mg/M. No standard for divinyl sulfide has been established in the United States. However, in the Soviet Union, where toxicological research on laboratory animals indicates that divinyl sulfide is a central nervous system depressant (Trofimov and Amosova, 1984), a maximum allowable concentration (MAC) of 0.2 mg/M has been recommended (Glukharev, et al., 1980). ... 

Maximum allowable concentration (MAC) A concentration of a substance or chemical calculated from long-term studies indicating that no significant adverse effect or harm would be produced to an exposed population. 

Below we give maximum allowable concentrations (MAC) of some disintegration products of triethyl- and triisobutylaluminum and their chlorides (in mg/m3) ... 

Based on the recommended maximum allowable concentration (MAC) values (Table VII), the H2S concentrations measured in the areas most frequented by construction personnel are well below the critical threshold. The highest H2S concentrations were measured inside the sulfur-... 

See also Benchmark Dose Exposure Assessment Exposure Criteria Hazard Identification Hormesis, LD50/ LC50 (Lethai Dosage 50/Lethai Concentration 50) Levels of Effect in Toxicoiogicai Assessment Maximum Allowable Concentration (MAC) Maximum Tolerated Dose (MTD) Pharmacokinetics/Toxicokinetics Reference Concentration (RfC) Reference Dose (RfD) Risk Assessment, Ecological Risk Assessment, Human Health Risk Characterization Toxicity, Acute. 

Maximum allowable concentrations (MACs) are the maximum airborne concentrations that can be justified consistent with the objective of maintaining unimpaired health or comfort of workers or both. The criteria on which the standard is established are the avoidance of (1) undesirable changes in body structures or biochemistry, (2) undesirable functional reactions that may have no discernible effects on health, and (3) irritation or other adverse sensory effects. 

The acceptable daily intakes set by the Joint Meeting on Pesticide Residues (JMPR) for cypermethrin, deltamethrin, and permethrin are 0-0.01 mg kg body weight, with acute oral reference doses for deltamethrin or permethrin of 0.05 mg kg bw. The National Institute for Occupational Safety and Health maximum allowable concentration (MAC) for pyrethrins at an 8 h time-weighted average is 5 mg m ... 

Commission, 2008). In this projected modification to the Directive, only 4 trace elements are listed Cd, Ni, Pb and Hg. For these elements, the values obtained in this study were compared with the maximum allowable concentrations (MAC-EQS) for inland surface waters when available (Table 4.5.2). In France, a Circulaire (2007) defines NQEp (which are the French translation of the European MAC-EQS). However, since there is still a need to evaluate the geochemical background for many trace elements in surface waters, it has to be borne in mind when comparing water quality data with NQEp values, that these are not yet the definitive values. Finally, data were compared with limits fixed for drinking waters (Decree, 2001). 

XLV-C TLV-C is the ceiling level concentration which must not be exceeded, even instantaneously. In some countries these are known as Maximum Allowable Concentration (MAC). 

Information of foodstuffs showed that in the period 1986-1990, there was a trend of increased levels of HCH, Lindane and DDT in fish products for 1986. However, absolute values did not exceed maximum allowable concentrations (MAC) (Figure 24.10) for meat products trends show an increase of HCH, in 1990 (Figure 24.2), The same trend was observed for residues of HCH in milk in 1990 (Figure 24.3). 

One accepted value of the maximum allowable concentration (MAC) of hydrogen sulfide to which a person can be exposed without injury to health is 20 ppm as set by the American Conference of Governmental Industrial Hygienists (ACGIH) (18). Although this level is not injurious to health, it does irritate the eyes. To prevent this irritation, a MAC of 5-10 ppm has been suggested (18). These two values were used to evaluate the relative toxicity of the hydrogen sulfide emissions in the preparation of the S-A-S mixes. 

Tab. 5.7 Ranges of Maximum Allowable Concentrations (MAC) of trace metals in agricultural soils reported most commonly in the literature (after Kabata-Pendias and Pendias 2001) and of Limit Values (LV) proposed by EEC Sludge Directive (after Stuczynski and Maliszewska-Kordybach 2001)... 

The saltwater aquatic life protection criterion of 4.5 tLg Cd/L seems adequate to prevent death, but will not prevent potentially deleterious physiological effects, including dismpted respiration in crustaceans and teleosts. Incidentally, at 5.0 ttg Cd/L, the lowest concentration critically examined, oysters biomagnify ambient levels to concentrations hazardous to human consumers and possibly other animal consumers. The maximum allowable concentration (MAC) in saltwater during a 24-h period was recommended as 59.0p,g/L (Table 5.2). However, death of various species of marine crustaceans was reported at 60.0 p,g Cd/L after exposure for 6 weeks and at 14.8-19.5 ttg/L after 23-27 days. Furthermore, a MAC of... 

The maximum allowable concentration (MAC) of Pb in drinking water in Europe is currently 50 p-g/L (which corresponds to the Pb concentration for water in contact with leaded pipes estimated by Patterson [6]), but this will be reduced to 10 pg/L by 2013. The MAC for Pb in drinking water in Canada today is 10 pg/L. The WHO recommended MAC had been 50 pg/L, but this was reduced in 1995 to 10 pg/L. 

Maximum allowable concentrations (MACs) for pesticides in water must take into account the effects on palatability and sanitary status. These data are compared with toxicological research to define an index of limits for use in establishing the MAC. If the organoleptic properties of water are affected by pesticide concentrations lower than those that produce threshold changes in tests on animals, palatability becomes the limiting index. If toxic alterations occur at concentrations that do not render the water unpalatable, the standard is set on the basis of toxicological criteria. Standards are established in a similar way for air. 

Maximum allowable concentration (MAC) See threshold limiting value. 

Threshold limit value (TLV) Limiting values established by OSHA or the ACGIH from toxic response vs. dosage data. Formerly referred to as maximum allowable concentration (MAC). There are three types of TLV TLV-C Ceiling limit. The concentration which should never l e exceeded, even instantaneously. When continuous monitoring is not feasible, this may be expressed as a 15-min STEL. 

Maximum Allowable Concentration (MAC) Exposure concentration not to be exceeded under any circumstances. Maximum Use Concentration (MUC) Also known as the Maximum Use Level or MUL. It is the maximum outside contaminant concentration a respirator can adequately protect against. The MUC can be calculated from the following relation MUC = PF or FF x PEL (or other standard). The MUC is limited to a chemical cartridge s rated capacity. 

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