Blooming testing

Not all cyanobacterial blooms and scums contain detectable levels of toxins. Indeed, the incidence of toxicity detection by mouse bioassay, and toxin detection by HPLC among environmental samples, ranges from about 40% to However, in view of this high occurrence, it is the policy of regulatory authorities and water supply operators in some countries to assume that blooms of cyanobacteria are toxic until tested and found to be otherwise. In the absence of available analytical facilities or expertise or for logistical reasons, this precautionary principle should be regarded as sensible and prudent. 

Bloom, J. M. (ed.) 1983 Probabilistic Fracture Mechanics and Fatigue Methods Applications for Structural Design and Maintenance. American Society for Testing and Materials. 

Exposure of the samples to a controlled moist atmosphere containing sulphur dioxide, as recommended in BS 1615 1972, Method H, is an example of a test bridging the gap between sealing tests and accelerated corrosion tests. After exposure for 24 h at 25 2°C, poorly sealed films show a persistent heavy white bloom, while good sealing produces at the most a slight superficial bloom. 

Development of proportional counters to measure C14/C12 ratios in 10 mg carbon samples was undertaken in the Chemistry Department of Brookhaven National Laboratory in 1975 [10] for two reasons (1) at the time, there was no other possibility in sight to accomplish the generally much-needed objective of small-sample C14 measurement, and (2) there was a particular carbon 14 dating problem at the Smithsonian Institution, which would only be solved if very small carbon samples could be handled. The development and testing of the counters has already been reported [9] in the present paper we discuss the application of those counters to the actual dating problem which concerned the Smithsonian Institution, the dating of the "Frobisher iron bloom". 

The appropriate animal model is also important when performing follow-up testing or additional mechanistic tests to further investigate findings observed as part of the routine preclinical safety tests. When possible, these studies should employ the same animals or animal model in which the change was initially observed for several reasons, as outlined by Bloom et al. (1987), including ... 

The resistance to blooming is tested by rubbing the colorations of differing concentrations with a white cloth immediately after they are produced, after 6 months storage at room temperature and, if necessary, also in an accelerated test after 24 hours storage at 70°C. 

In the print field the pigment is almost exclusively used in air drying systems. P.R.4 is very likely to bloom in stoving enamels. At only 120°C, the concentration limit for blooming is as low as 2.5%, and at 140°C the limit is at 5%, which makes it necessary to carry out test experiments. Application is consequently restricted to baking enamels targeted for low temperature purposes. In epoxy resins, the pigment turns brown, as does P.O.5, and is therefore unsuitable for use in these media. 

Galloway, S.M., Bloom, A.D., Resnick, M., Margolin, B.H., Nakamura, F., Archer, R Zeiger, E. (1985) Development of a standard protocol for in vitro cytogenetic testing with Chinese hamster ovary cells Comparison of results for 22 compounds in two laboratories. Environ. Mutag, 1, 1-51... 

Calfskin gelatin (60 bloom strength), bovine casein and the amino acids tested (phenylalanine, leucine, tyrosine, tryptophan) were all purchased from Sigma Chemical Company (St. Louis, MO). 

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