High potential hazard

High potential hazard The health, fire, or explosion risk resulting from the presence of certain materials in excess of a certain limit. 

The Ames test involves the reversion from a his— to his+ phenotype in any one of multiple bacterial strains (usually five strains are tested simultaneously). If the addition of test compound to a his— strain of bacteria allows them to grow on histidine deficient media, the obvious conclusion is compound-induced mutagenesis and a high potential hazard for the compound being carcinogenic. This test can also be conducted in the presence or absence of metabolic activation, in order to provide more information on potential risks (i.e., the parent compound may not be mutagenic, but the primary metabolite may present a safety risk). In practice, a positive Ames test almost always leads to discontinuing work on a compound of interest, and so these data are always collected prior to nomination of a compound for development. 

Although substitution of a hydrogen atom or an alkoxy group for one alkyl group in a trialkylaluminium tends to increase stability and reduce reactivity and the tendency to ignition, these compounds are still of high potential hazard, the hydrides being used industrially as powerful reducants. 

In the author s opinion, high voltage electrophoresis, in spite of its potential advantages is a technique which requires relatively expensive equipment of high potential hazard and is therefore unsuited for the large-scale screening of aminoacidopathies in most routine clinical chemistry laboratories. 

One of the cornerstones of the EH S program is the new, revised laboratory safety plan program. The goal of the revised program is to develop the best possible understanding of the operation of each lab. The results of lab inspections and hood surveys, and reviews of facility modification requests from laboratories all go into an EH S data base designed to facilitate evaluation of sites of high potential hazard. 

Fixed H2S detectors should be provided in high potential hazard H2S areas defined as ... 

The presence of naturally occurring ozone in the lower stratosphere creates a potential hazard for passengers and crew members of high flying aircraft (163,164). Ozone in the inlet air to the aircraft cabin, which can reach 1.2 ppm, is destroyed catalyticaHy. 

The only components in a coating powder which might cause the waste to be classified as hazardous are certain heavy-metal pigments sometimes used as colorants. Lead- (qv) and cadmium-based pigments (qv) are seldom used, however, and other potentially hazardous elements such as barium, nickel, and chromium are usually in the form of highly insoluble materials that seldom cause of the spent powder to be characterized as a hazardous waste (86). 

Molybdenum because of its unique chemical versatility and unusually high bio-availability has been incorporated widely into biological systems. It is the only second-row transition metal that is essential for most of living organisms and belongs to elements (along with Cu, Cd, Hg, Pb and Cr) potentially hazardous to humans. 

It is important that the formaldehyde addition rate be balanced with the alkali content of the system and the engineering control capability. At high alkali contents, the exotherm will be more vigorous and create more load on the heat exchangers. At low alkali contents, the reaction rate may be quite slow. While this temporarily reduces the difficulty in instantaneous heat load, it may permit potentially hazardous levels of unreacted formaldehyde to accumulate. Such accumulations could become dangerous as batch temperature rises. In both cases. 

Diatomaceous earth, widely-known and long-used as a filteraid in process and waste filtrations, has a high microcrystalline silica content. As well as being a respiratory hazard in the workplace, the silica is being scrutinized in some jurisdictions as a potentially hazardous dust in landfills in which spent filter cakes are deposited. 

Table 13.16 sets out the major waste disposal methods, and potential hazards from toxic waste deposition are indicated in Table 13.17. The range of precautions required at land tips depends upon the risk, e.g. the nature and degree of contamination and the work to be undertaken. It will, however, encompass personal protective equipment a high standard of personal hygiene enclosure, possibly pressurization, and regular cleaning of vehicle cabs vehicle washing facilities site security, and control of designated dirty areas. Air monitoring and medical surveillance may be required.

Viruses are infectious particles formed by nucleic acid, proteins, and in some cases lipids. As viruses (for example, retro- and adenoviruses) transfer viral genes into cells with high efficiency, modified forms are sometimes used as vectors for gene transfer. However, procedures using virus-based vectors are often significantly more complicated and time-consuming than other transfection methods. In addition, viral vectors are potentially hazardous, and biological safety issues need to be considered carefully. Therefore, techniques that combine... 

Based on the experience gained during the past U to 5 years, it was demonstrated that no pesticides were canceled on the basis of unacceptably high levels of N-nitroso contaminants. It is anticipated that the EPA Nitroso Policy will improve pesticide products even further by a reduction or elimination of N-nitroso contaminants from potential sources. In this way, the human risk from these potentially hazardous chemicals will be minimized. 

---