Gloves materials

General advice on the suitability and degree of resistance of glove materials are summarized in Table 13.12. In all cases, however, in addition to the necessary mechanical properties (i.e. resistance to abrasion, blade cut resistance, tear resistance and puncture resistance rated according to European Standard EN 388), consideration should be given to the resistance to the specific chemicals involved. 

Some glove suppliers also provide data on, or a noting of, degradation, i.e. die physical effects which a chemical will have upon a particular glove material. 

Table 13.12 Glove material resistance rating (courtesy ames North Sons Ltd)...

Chemical Natural rubber Glove material Neoprene Nitrile Normal PVC High grade PVC... 

We have already met one tool that can be used to investigate the links that exist among data items. When the features of a pattern, such as the infrared absorption spectrum of a sample, and information about the class to which it belongs, such as the presence in the molecule of a particular functional group, are known, feedforward neural networks can create a computational model that allows the class to be predicted from the spectrum. These networks might be effective tools to predict suitable protective glove material from a knowledge of molecular structure, but they cannot be used if the classes to which samples in the database are unknown because, in that case, a conventional neural network cannot be trained. 

The choice of the most appropriate glove materials to provide protection when handling toxic chemicals. 

GloveAID ( ) predicts the most effective glove materials to choose for protection against hazardous chemicals. There are no established experts in this field, because much of the protection effectiveness measurements are Just now being performed. The inductive learning aspect of RuleMaster is used to help organize the date which is available and to suggest which measurements should be performed next. 

TABLE I. INITIAL GLOVE MATERIAL RATINGS SORTED BY CHEMICAL CLASS... 

The easiest way to describe the rule induction capabilities of Rule-Master is to demonstrate its use with a relevant set of data. This data consists of information on a series of nonhalogenated aromatic compounds which were tested with five different glove materials. An arbitrary protective rating was assigned to each test based on the following breakthrough times ... 

There are no glove materials In the data base meeting the requirements that you specified The closest are ... 

RuleMaker, a subsystem of RuleMaster, induces rules for all situations from examples that may cover only some of the cases. At the heart of the induction process is the creation of an induction file, which in part includes examples indicating what the expert system should do under different circumstances. Now, in the example above, THE RULES FOR CORRELATING VARIOUS CHEMICAL AND PHYSICAL PARAMETERS OF THE HAZARDOUS CHEMICALS TESTED WITH THE PROTECTIVE ABILITY OF THE SELECTED GLOVE MATERIALS ARE NOT KNOWN — THEY WILL HAVE TO BE INDUCED FR04 THE ANALYTICAL DATA. 

The experimental data in this illustration comprise the actual rule base for RuleMaker. The first coltmin of data in the EXAMPLE section of Figure 5 consists of the glove material tested. The second coltomn of data consists of the molecular weights, and the third column consists of the boiling points in degrees centigrade. 

If the glove material is nitrile, and compounds have a molecular weight <118 and boiling points >= 142 C. the rating is POOR. 

Figure 8. Protective Ranges of Six Glove Materials Against Non-halogenated Compounds.

Environment and health-related problems DCM is toxic for the central nervous system, for the liver and the kidneys (MAK-value 350 mg/m ), and it is absorbable via skin. Furthermore DCM is a suspected carcinogen (classification care, cat 3). DCM is low volatile and the vapour is heavier than air, thus high concentrations may occur at ground level during application. Activated-carbon-filters are ineffective and normal glove materials are penetrated within a few minutes. The required breathing equipment is, however, hardly used by craftsmen, which results in several deaths every year. 

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