Compatibility assessment tests

Compatibility assessment tests aim to evaluate the resistance of a metal or alloy in a given medium such as hypochlorite solution or phenol solution or any other chemical product or media of more complex composition. The method, long in use, is quite simple samples are immersed in the relevant solutions for a defined period of time (hours, days), depending on... 

Hardware changes Assess new hardware for compatibility with the existing hardware. Should any differences be identified, fhese shonld be assessed/tested against the existing LIMS design intent. 

The compatibility/screening tests are, in a sense, prerequisites for a polymer solution to be selected and involve polymer/brine compatibility, filterability, sensitivity to other additives, etc. If a given polymer, or polymer type, fails such screening tests, then it should be excluded from the candidate polymer list unless there is a simple technical solution which remedies the problem. The polymer core flood data are essentially the information that is collected in the laboratory that may be used directly (or indirectly) in the polymer simulations to assess the viability of the polymer pilot flood. Information such as concentration/viscosity behaviour, adsorption/retention levels, degree of permeability reduction, and in-situ rheology would come under this category. The importance of controlling the exact experimental conditions under which this type of data is collected will be discussed below. The third type of experiment relates to the oil displacement efficiency of the polymer solution and is usually only carried out in short linear systems. This type of experiment is of somewhat limited value for the reasons discussed below. 

Another area of interest in the defence industry is the security of supply of key ingredients and the identification and qualification of new or replacement materials. It is increasingly difficult (and in many cases impossible) to purchase the exact same materials used in the production of early assemblies/materials. The preferred option for material supply (particularly the organic materials, with volatile constituents) in the defence industry is to have greater (in-house) control over the production of constituents and formulation of materials. All programmes to develop new or replacement materials require the delivery of assessments/tests to understand the ageing and chemical compatibility issues. 

Method for total immersion corrosion test for tank-type aircraft maintenance chemicals Method for total immersion corrosion test for aircraft maintenance chemicals Practice for assessment of compatibility of bio-materials (non-porous) for surgical implants with respect to effect of materials in muscle and bone... 

There shall be a written assessment of stability based at least on testing or examination of the drug product for compatibility of the ingredients, and based on marketing experience with the drug product to indicate that there is no degradation of the product for the normal or expected period of use. 

Level 1 sampling provides a single set of samples acquired to represent the average composition of each stream. This sample set is separated, either in the field or in the laboratory, into solid, liquid, and gas-phase components. Each fraction is evaluated with survey techniques which define its basic physical, chemical, and biological characteristics. The survey methods selected are compatible with a very broad spectrum of materials and have sufficient sensitivity to ensure a high probability of detecting environmental problems. Analytical techniques and instrumentation have been kept as simple as possible in order to provide an effective level of information at minimum cost. Each individual piece of data developed adds a relevant point to the overall evaluation. Conversely, since the information from a given analysis is limited, all the tests must be performed to provide a valid assessment of the sample. 

Source characterization results are not located in a centralized facility which is constantly updated. The Environmental Protection Agency has established the Environmental Assessment Data System (EADS) (31) which contains chemical compositions of particulate matter emissions tests. This existing computerized structure can provide the centralized location for receptor model source characterization information. Procedures such as those described for ambient data in the previous section need to be developed in order to allow receptor model users access to this data base over telephone lines. The data required of receptor model source tests should be incorporated into the EADS, and source characterization results should report this information in an EADS compatible format. 

The vacuum stability test (VST) is considered the most acceptable test for measuring stability and compatibility of explosives, worldwide. This is an empirical test in which rate of gas evolution is measured under isothermal conditions and a limit of 01 cm3 of gas per gram of an explosive is set for explosives heated at 120°C (150°C for RDX) for 40h (25h for PETN). A similar test but at somewhat lower temperatures, is used to assess compatibility of an explosive with other explosives or with non-explosive materials such as binders (polymers), plasticizers etc. 

Excipient compatibility studies are a form of preliminary stability assessment. It is important that they be executed appropriately. The precise details of the testing will probably be different for each organization carrying out such studies. However, certain general assumptions are implicit in this approach. The underlying principle is the Arrhenius relationship ... 

Walker, A.P., Basketter, D.A., Baverel, M., Diembeck, W., Matthies, W., Mougin, D., Paye, M., Rothlisburger, R., and Dupuis, J. Test guideline for assessment of skin compatibility of cosmetic finished products in man. Food Chem. Toxicol. 1996 34 551-560. 

IgE antigens combined with in vitro tests of cross-reactions of IgE and sequenced antigens, as it has been found that the basic condition for positive cross-reactivity is the high structural compatibility (homology) of reagents. Compared to B-cells, T-cell cross-reactivity is far more difficult to assess because the mechanism of T-cell effects is more diverse and involves both the phase of immunological response and the effect phase of the allergic reaction. 

Flame-retardants that have gone through a EU Risk Assessment under Regulation 793/93/EC should be some of the first substances registered under the REACH. Several flame-retardants have already been tested by the EU and found to be compatible with the strict safety criteria of REACH, such as PBT and CMR criteria. 

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