Testing compatibility

A humorous example of compatibility testing occurred during the initial development of the SCF system. A group of executives were touring the facility and were given a demonstration of the SCF system as a possible replacement cleaning process for other product lines. There was a great deal of interest in this process and one 

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Compatibility tests Compatibility value C o mp atib ill 2 ati o n Compatibilizers... 

Because of the number of chemicals and subsequent multiple number of potential reactions, it is impractical and (perhaps impossible) to list all potential reactions. Several systems exist for determining the reactions between classes of chemicals, however, none of them is definitive. Because all of the potential reactions for individual chemicals are not cataloged and because there are no (or very few), pure solutions of waste materials, laboratory compatibility testing is recommended for most materials. An appropriate protocol for compatibility testing would involve the following steps ... 

Compatibility testing is almost by nature an experiment with the unknown. As such, safety must be the watchword. Procedures for compatibility testing should take into account the most severe adverse reaction possible, not just that expected. Such... 

Aryloxyphosphazene polymers, such as compound 1 or its mixed-substituent analogs, are also hydrophobic (contact angles in the region of 100°). These too show promise as inert biomaterials on the basis of preliminary in vivo tissue compatibility tests (13). 

Although the initially reported tissue compatibility tests for subcutaneous implants of poly(BPA-iminocarbonate) were encouraging (41,42), it is doubtful whether this polymer will pass more stringent biocompatibility tests. In correspondence with the properties of most synthetic phenols, BPA is a known irritant and most recent results indicate that BPA is cytotoxic toward chick embryo fibroblasts in vitro (43). Thus, initial results indicate that poly(BPA-iminocarbonate) is a polymer with highly promising material properties, whose ultimate applicability as a biomaterial is questionable due to the possible toxicity of its monomeric building blocks. 

Fig. 1. Competition binding screens Bead/ligand compatibility test in early assay development. The beads PVT-WGA, Type A and Type B are based on polyvinyltoluene (PVT) not polyethyleneimine (PEI). PVT, polyvinyltoluene WGA, wheat germ agglutinin Ysi, yttrium silicate.

To avoid compatibility problems, compatibility tests under conditions typical for the planned application are performed. From their results suitable material combinations are selected. Figure 110 shows a compatibility test for metals in contact with inorganic PCM. Test tubes containing both materials (center) are kept in a controlled environment for a fixed time (left) and later effects on the metal are analyzed (right). 

Figure 110. Compatibility test for metal-inorganic PCM combinations...

Figure 111. Compatibility test for plastic-inorganic PCM and plastic-organic PCM...

Chemical compatibility tests using U.S. EPA Method 909040 should always be performed for hazardous waste sites, but some municipal waste sites also contain hazardous, nondegradable materials. U.S. EPA conducted a 5-year study of the impact of municipal refuse on commercially available liner materials and found no evidence of deterioration within that period. However, in a current study of leachate quality in municipal landfills, the Agency has discovered some organic chemical constituents normally found in hazardous waste landfill facilities. Apparently, small quantities of household hazardous waste enter municipal sites or are disposed of as small quantity generator wastes. As a result of these findings, U.S. EPA developed a position on the need for chemical compatibility tests for thousands of municipal waste disposal sites. 

A primary objective of chemical compatibility testing is to ensure that liner materials will remain intact not just during a landfill s operation but also through the postclosure period, and preferably longer. It is difficult, however, to predict future chemical impacts. There is no guarantee that liner materials selected for a site today will be the same as materials manufactured 20 years from now. For example, the quality of basic resins has improved considerably over the last few years. 

A designer should consult with experts to interpret data from chemical compatibility tests. To meet this need, U.S. EPA developed a software system called Flexible Membrane Liner Advisory Expert System (FLEX) to assist in evaluating test data. FLEX is an expert system that is based on data from many chemical compatibility tests and contains interpretations from experts in the field. 

U.S. EPA, Compatibility Test for Wastes and Membrane Liners, EPA Method 9090A, Revision 1, July 1992, U.S. Environmental Protection Agency, http //www.epa.gov/epaoswer/hazwaste/test/pdfs/9090a. pdf, 2009. 

EPA, Method 9090A, Compatibility test for wastes and membrane liners, EPA, US, 1986. 

Serajuddin, A.T.M., Thakur, A.B., Ghoshal, R.N., Fakes, M.G., and Varia, S.A., Selection of solid dosage form composition through drug-excipient compatibility testing, /. Pharm. Sci., 88, 696, 1999. 

PQ System compatibility tests under operational conditions at defined limits. 

L.2.5 Epoxy grout shall pass the thermal compatibility test when overlayed on cement grout using test method ASTM C 884. 

In the typical dmg-excipient compatibility testing program, binary powder mixes are prepared by triturating API with the individual excipients. These powder samples, usually with or without added water and occasionally compacted or prepared as slurries, are stored under accelerated conditions and analysed by stability-indicating methodology, for example, HPLC, CE and so forth. This entire process takes considerable time and resources. 

Costs likely to be incurred in the design and installation of a standard soil-bentonite wall in soft to medium soil range from 540 to 750/m ( 5 to 7/tf) (1991 dollars). These costs do not include variable costs required for chemical analyses, feasibility, or compatibility testing. Testing costs depend heavily on site-specific factors (D109308, p. 2). The installation cost of a cement-based slurry wall ranges from 10 to 20 per vertical square foot for a 2-ft-wide barrier of less than 100 ft in depth (D18976I, p. 6). 

Forbes MJ (1980) Cross-flow filtration, Transmission electron micrographic analysis and blood compatibility testing of collagen composite materials for use as vascular prostheses. M.S. Thesis, Massachusetts Institute of Technology, Cambridge, MA... 

Reviewed by G. Cohn, Edit in Expls Pyrots 6(4), 1973- (This compilation records compatibility testing at Pieatinny Arsenal. Compatibility indicator was the result of gas evolution determined in (he vacuum stability test. Reports present the information in two ways by generic name or trade name of the plastic and by explosive. The reader can quickly scan the information to see with what expls a plastic is compaticle and what plastics can be used safely with a particular explosive)... 

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