Chemical monitoring United Kingdom

In the United Kingdom one of the chemicals monitored regularly is the coccidiostat nicarbazin, which is not licensed for use in laying hens and, therefore, any positive samples create cause for concern. The results of surveillance of the incidence of nicarbazin in eggs during the period 1996-1997 are presented in Table 13.22. 

Skin tissues isolated from rats, rabbits, and humans have been monitored in vitro to predict penetration and irritation. The rat epidermal slice technique has been validated as a screen for corrosive substances. The electrical impedance changes as the integrity of the stratum corneum is altered. The use of this technique to predict irritancy is being investigated in the United Kingdom. Another method studies enzyme changes when a substance is applied to a slice whose lower surface is bathed in culture medium. Enzyme changes separate irritant and nonirritant chemicals. 

Harden and Blyth exchange results and meet, agreeing to develt IMS jointly. Eventually, the responsibility of the U.S. mihtary was to produce a continuous air monitor known as the ACADA (automatic chemical agent detector and alarm), and the United Kingdom was to develt a personal monitor, eventually called CAM, the chemical agent monitor, a handheld IMS analyzer. 

Programs to develop IMS-based detectors and monitors for CWAs were undertaken with the support of defense establishments in several governments, notably the United Kingdom and United States. In the United States, research toward the development of an automatic chemical agent detector and alarm (ACADA) was begun but later discontinued. Efforts were resumed by Smiths Detection, and the result has been placed into service as the GID-3 and its later models, like the GID-M." The intention for this analyzer is to continuously monitor the presence of CWAs in ambient air and sound the alarm when threshold values are exceeded. The GID-3 and all other IMS-based analyzers are regarded as point sensors and cannot determine chemical compositions at distances greater than a few meters in the absence of breezes. 

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