Minimum risk levels

HUMAN HEALTH Minimum risk level, oral Safe daily dose Acceptable daily intake Air Arizona 5 pg/kg body weight daily for acute duration oral exposure of 14 days or lessb 1 pg/kg BW daily for intermediate duration exposure of 15-364 days (USPHS 1994) 3.4 pg/kg body weight (USEPA 1980a) 1.25 pg/kg body weight (USEPA 1980a)... 

Note The term minimum risk level (MRL) is used by the ATSDR. 

Used to derive an acute oral Minimum Risk Level (MRL) of 0.05 mg/kg/day dose divided by an uncertainty factor of 100 (10 for extrapolation from animals to humans and 10 for human variability). 

Levels of silver exposure that have led to argyria in humans in the past are poorly documented, and it is not possible to establish minimum risk levels for this effect based on these data. Hill and Pillsbury (1939) in their review of cases of argyria report that total doses of silver that have resulted in argyria can be as low as a total of 1.4 grams of silver (as silver nitrate) ingested in small unspecified doses over several months. 

Used to derive an intermediate-duration oral exposure minimum risk level (MRL) of 0.002 mg/kg/day adjusted by an uncertainty factor of 30 (3 for use of a minimal LOAEL and 10 for variability among humans)... 

Minimum risk level (MRL) An estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse noncancer health effects over a specified duration of exposure. 

Minimum risk level, oral 5.0 JLg/kg BW daily for acute duration exposure of 14 days or less 1.0 iig/kg BW daily for intermediate duration exposure of 15-364 days... 

Invariably, those who oppose the use of the term acceptable risk offer substitutions. One frequent suggestion is that designers and operators should achieve minimum risk levels or minimize the risks That sounds good, until application of the terms is explored. Minimum means the least amount or the lowest amount. Minimization means to reduce something to the lowest possible amount or degree. 

Requiring that systems be designed and operated to minimum risk levels— that risks be minimized—is impractical because the investments necessary to do so may be so high that the cost of the product required to recoup the investment and make a reasonable profit would not be competitive in the market place. 

If the mean urine pH of cats fed ad libitum is not below 6.4, the risk of stmvite uroHthiasis iucreases as the magnesium content of the diet iucreases. Because of very poor bioavailabiUty, iron from carbonate or oxide sources that are added to the diet should not be considered as components ia meeting the minimum nutrient level ia cats. 

The aim of a risk assessment is to develop a product which is safe for the proposed market. A safe product is any product which, under normal or reasonably foreseeable conditions of use, including duration, presents no risk or only the minimum risk compatible with the product s use and which is consistent with a high level of protection for consumers (DTI, 1994). In attempting to protect products against failure in service and, therefore, the user or environment, difficulty exists in ascertaining the... 

In the North Sea this is often done with detailed quantified risk assessments and the calculation of an overall IRR or risk of total loss of structure. Mitigation measures are incorporated until it can be shown that risk levels meet a minimum criteria and the cost of further mitigation has such high cost to benefit ratios that further mitigation is no longer practicable. ... 

Algorithm 1 requires the a priori selection of a threshold, s, on the empirical risk, /en,p( X which will indicate whether the model needs adaptation to retain its accuracy, with respect to the data, at a minimum acceptable level. At the same time, this threshold will serve as a termination criterion for the adaptation of the approximating function. When (and if) a model is reached so that the generalization error is smaller than e, learning will have concluded. For that reason, and since, as shown earlier, some error is unavoidable, the selection of the threshold should reflect our preference on how close and in what sense we would like the model to be with respect to the real function. 

Minimal Risk Level (MRL), 25 239 Minimum allowable continuous stable flow (MCSF) limits, for pumps, 21 83 Minimum bactericidal concentrations (MBCs), 18 262... 

Toxicity Excessive doses may cause severe toxicity monitor serum levels to ensure maximum benefit with minimum risk. 

If, on the other hand, one is interested in determining the minimum acceptable sample process capability index Cp required to have some stated confidence 100(1 — a)% that the true Cp is above some value (e.g., Cp = 1.0), one can use the following equation for a particular Cp, sample size n, and risk level a ... 

Let us specify some very low risk level as that which we would not like to see exceeded. Pick an extra lifetime probability of cancer of 0.00001 (1 in 100000). For purposes of this discussion, this risk will be considered tolerable. This probability is 10000 times smaller than the minimum risk for which we have dose—response data (0.1, see Figure 5). If we adopt hypothetical dose-response model A, the linear, nothreshold model, then we see that dose A produces an extra lifetime risk of 1/100000. Similarly, model B yields dose B as producing the same risk. 

A vast array of alternative specifications is also possible. Practitioners often employ additional inequality constraints on portfolio weights, limiting them to maximums, minimums, or linear combinations. For example, total equity exposure may be restricted to a percentage of the portfolio or cash to a minimum required level. Another common variation is to add inequality constraints to force solutions close to benchmarks. This minimizes the risk of underperforming. 

Floating-rate notes can include additional features. One example is the inclusion of cap, floor and collar clauses. A floater with cap feature means that the reference rate cannot overcome the threshold rate defined in the indenture. Usually the threshold is expressed in terms of coupon, that is after a coupon threshold (e.g. 6%, reference rate plus quoted margin) the investor receives at maximum the cap level. In this case, the floater is not completely covered by rising interest rates, in which after the threshold the floater trades as a conventional bond. In contrast, a floater with a floor feature represents the minimum coupon level that an investor can receive, hedging to the downside risk of interest rates. If the bond includes both cap and floor, this feature is known as collar or collared floating-rate note. The bond can include also a drop-lock feature that after a threshold it ceases to float. 

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