CEN requirements

CEN requirements for widely accepted multi-matrix/multi-residue methods... 

ISO 16602, Protective Clothing for Protection against Chemicals—Classification, labeling, and performance Requirements utilizes a 6 tier system similar to that found in the CEN standards. While there is subtle difference between the ISO and CEN requirement, garments will generally, but not always, meet the requirements of a given level in strategies. 

NDT equipment imported in lots in the process of state testing are examined both on their conformity to the requirements of safety standards (ISO, CEN, lEC) and standards of the manufacturer and its availability for calibrartion in service. 

In Europe, the gas safety controls must meet the requirements of CEN standards, including flame failure devices, solenoid control valve, pilot con trols, ignition and governor. Overheat-type thermostats and either a pressure switch or an airflow-proving device are fitted to ensure that the burner will cut off in the event of no air flowing through the heater, such as occurs with fan failure. 

The control system must satisfy a set sequence, as is required by CEN or other standards. An air switch provides airflow to the unit. A 30-second purge of the unit takes place by the fan after this period, the ignition spark and pilot gas valve are operated. 

All burners should meet the requirements of CEN or other national standards. The units must be complete with safety devices for ignition failure and main flame failure. 

A new CEN Enropean standard, EN 12874, was issued in 2001. It will be nsed by all Enropean nations that belong to the Enropean Union (EU), as well as other non-EU nations that are members of the CEN. This is a very comprehensive standard covering many aspects of flame arrester technology, indnding specific requirements for the following ... 

CEN (Comite Europeean de Normalisation) Std. EN12874. 2001. Flame Arresters-Speeifieations, Operational Requirements and Test Procedures. European Committee for Standardization, Brussels, Belgium. 

The more comprehensive CEN standard makes it likely that an approved device is available for almost any application. In certain difficult applications it may be required to make modest design changes in order to accommodate the flame arrester and its capabilities, but this is preferable to being stuck with an application where no approved flame arresters are available. 

The European Commission has mandated CEN/CENELEC to develop many standards to support manufacturers in the realisation of the essential requirements of the Directives. If the Commission determines that an adopted standard is fit for this purpose, then a reference is published in the Official Journal of the EU, which elevates the status of the standard to that of a harmonised standard for European regulatory purposes. 

CEN/CENELEC (1989) General requirements for the competence of testing and calibration laboratories. EN 45001. 

Within CEN TC 275, a distinct protocol for the conduct of inter-laboratory method validation trials is not selected or required, but it is recommended to apply ISO 5725 or the ISO/International Union for Pure and Applied Chemistry (lUPAC) harmonized protocol. " In the past, results of several national and international interlaboratory trials had been accepted. Nevertheless, the following fundamental aspects of the harmonized protocol for the design of method-performance studies should be fulfilled ... 

In Europe, very different concepts of method validation are in use. The extent of validation depends upon legal requirements (e.g., for enforcement methods provided by the applicant), upon the required level of acceptance (e.g., for CEN methods) and upon national resources. Undoubtedly, the best method validation is performed with the help of inter-laboratory studies of performance, but such studies can be uneconomic, too slow to reach completion or restricted in scope. 

The integration of analytical methods in European standards requires their acceptance by several national experts within special working groups and in a final weighted vote of National Standards Bodies. Therefore, there needs to be very high confidence in the performance of methods. Consequently, methods should be tested in inter-laboratory method validation studies, with the exception of those multiresidue methods which are widely used throughout Europe. In the case of CEN methods there is no doubt about residue definition but detailed requirements about the number of matrices and concentration levels in validation experiments do not exist. Eor this reason it may be that CEN methods are validated for important crops only. 

Thiolactomycin (16) is another natural product that reversibly inhibits E. coli FabF, FabB, and FabH with respective ICso s of 6, 25 and 110 (iM. Unlike cerulenin, it binds the malonyl-ACP site of the enzyme [27]. Despite modest double-digit MICs on . coli, S. aureus, Serratia marces-cens, and Mycobacterium tuberculosis, 16 has generated quite some interest due to its good in vivo protection against an oral or intramuscular S. marcescens urinary tract infection model where it displayed rapid tissue distribution [28]. Despite several medicinal chemistry efforts, thiolactomycin has proven difficult to optimize due to some strict functional group requirements for its SAR [29]. 

At the same time, the abundance ratios among the elements heavier than Al, at least through the Fe peak, do not show any detectable variation in any known GC (except, of course, iv Cen). The rock steady abundances for these elements requires explanation as well, and places important constraints on the formation mechanisms of GCs. 

The development of methods of analysis for incorporation into International Standards or into foodstuff legislation was, until comparatively recently, not systematic. However, the EU and Codex have requirements regarding methods of analysis and these are outlined below. They are followed by other International Standardising Organisations (e.g. AOAC International (AOACI) and the European Committee for Standardization (CEN)). 

There are other international standardising organisations, most notably the European Committee for Standardization (CEN) and AOACI, which follow similar requirements. Although CEN methods are not prescribed by legislation, the European Commission places considerable importance on the work that CEN carries out in the development of specific methods in the food sector CEN... 

Many of the more established techniques have been validated through collaborative studies which becomes of greater importance as laboratories seek to become accredited via ISO, EN or related systems where the use of official or well validated methods is mandatory. New instrumental techniques are constantly being reported in the literature but it often requires many years before procedures are introduced, validated and then applied within the food industry. Recent techniques that can be included in this category are capillary electrophoresis and liquid chromatography-mass spectrometry (LC-MS). In time procedures based on these techniques will also become accepted as routine methods and are likely to be adopted by some of the official international bodies like the AOAC International, CEN, ISO, etc. 

European Communities are presumed by Member States to comply with those aspects of the essential requirements that are covered by the standard. Harmonised standards are those adopted by the EC standards bodies pursuant to a mandate issued by the Commission, in this case the European Committee for Standardisation (CEN) and the European Committee for Electrotechnical Standardisation (CENELEC). A large number of standards are contemplated but may take time to be written and adopted. Standards may be horizontal (covering aspects common to all or a number of product types) or vertical (dealing only with a specific aspect or specific product type). Important harmonised standards exist on the following ... 

Bangers have ceased to be available to the general public in the UK since 1997, on safety grounds. More recently, the CEN (European Standardisation of Fireworks) has set maximum sound level requirements of 120dB at distances of 1, 8 and 15m for Category 1, 2 and 3 (nitrate or perchlorate based) flash bangers respectively. 

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