Average limits

The time-weighted, 8-h average limit for exposure to bromine pentafluoride is 0.1 ppm (67). Materials of constmction suitable for use with the bromine fluorides include nickel. Monel metal, or Teflon. For shipping, bromine trifluoride and pentafluoride are classified as oxidizers under DOT regulations. The trifluoride also requires a poison label. 

Table 1. Permissible Excursions for Time-Weighted Average Limits...

Influence of mercury column height. In the above Ilkovic equations for the average limiting current m and [Pg.134]

The primary current distribution is uniform on the hemisphere. Numerical calculations using the potential theory have shown that the current distribution is essentially uniform on the RHSE if the current density is less than 68% of the average limiting current density [47]. 

The average Sherwood number, Shiv, and average limiting current density, iljmjav, can be obtained by integrating Eqs. (40)-(41) over the electrode surface. The results for a hemisphere, whose entire surface is subject to mass transfer are ... 

The average limit of a tolerable daily intake was fixed by the World Health Organization (WHO) as 0.5 p-gkg-1 day-1 for triphenyltin and this figure corresponds to an allowed concentration in fish of 0.25 Xgg-1. About half the triphenyltin concentrations shown in Figure 6 are higher than the limit of 0.25 pgg-1. The decline of these triphenyltin concentrations is expected since the banning. 

The Occupational Health and Safety Administration (OSHA) has limited workers exposure to 1,2-dibromoethane in air to an average of 20 ppm for an 8-hour workday. According to OSHA, short-term exposure of 15 minutes to 1,2-dibromoethane should not be more than 0.5 ppm. The National Institute for Occupational Safety and Health (NIOSH) has set an average limit for 1,2-dibromoethane of 0.045 ppm in workroom air during an 8-hour day. According to NIOSH, short-term exposure of 15 minutes to 1,2-dibromoethane should not be more than 0.13 ppm. 

An 8 hour time-weighted average limit (TWA) of 0.2 fiber per cubic centimeter (f jcc) of air based on an 8 hour time-weighted average (TWA) sampling period. This is the maximum level of airbome asbestos, on average, that any employee may be exposed to over an 8 hour period (normal work shift). 

X The 3X decontamination level refers to solids decontaminated to the point that the agent concentration in the headspace above the encapsnlated solid does not exceed the health-based, 8-honr, time-weighted average limit for worker exposure. The limit for HD is 3.0 jg per cubic meter of air. Materials classified as 3X may be handled by qualified plant workers using appropriate procedures but cannot be released to the environment or sold for general public reuse. In specific cases in which approval has been granted, a 3X material may be shipped to an approved hazardous waste treatment facility for disposal in a landfill or for further treatment. 

Table 3 Averaged limits of detection (LOD) and limits of quantitation (LOQ) (pM 2,3,7,8-tetrachlorodibenzo-p-dioxin [2,3,7,8-TCDD]/ well) over all experiments, by participant SD = standard deviation %SD = percentage standard deviation...

Table I. Average Limiting Viscosity Number and Weight-average, Molecular Weight for the Poly(l-amidoethylene) Sample...

The main sources of exposure to mercury for the general population are from the diet and dental amalgam.21,28 The main dietary source of mercury is fish and this has led to interest in potential exposure to mercury on the neurological development of children from populations with high fish consumption.29 There is no statutory control of mercury in most food in the UK, but the levels of mercury in fish are controlled by European Commission Decision 93/351/EEC which sets an average limit for mercury in fish of 0.5 mg/kg or 0.5 ppm (part per million).30 This average limit is, however, increased to 1.0 mg/kg or 1 ppm for the edible parts of the predatory and bottom-dwelling species listed in the Annex to the Decision. 

Commission Decision 93/351 lays down maximum limits for mercury in fishery products and methods of sampling and analysis to check compliance with these limits. This Decision was made after consulting the Standing Veterinary Committee. The mean total mercury content of the edible parts of fishery products must not exceed 0.5 mg/kg of fresh weight. However, this average limit is increased to 1 mg/kg fresh weight for the edible parts of certain... 

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