Decontamination defined

Following approach 1, if <1.0 VSL, the waste is classified as clean and shipped offsite, and if >1.0 VSL, approach 2 or approach 3 is followed (PMACWA. 2006). Adequate decontamination, defined as <1.0 VSL, may need to be accomplished in the SDU or the autoclave and verified via monitoring at the SDU or the autoclave. As previously indicated, Table 4-6 shows the total estimated secondary wastes, while Tables 4-7 and 4-8 show projected generated quantities of contaminated secondary wastes according to their level of contamination (before any onsite treatment) for the operational and closure stages of PCAPP, respectively. 

Biosafety Level 2 (BSL-2) Similar to Biosafety Level 1 and is suitable for work involving agents of moderate potential hazard to personnel and the environment. Required practices are BSL-1 practices plus limited access, biohazard warning signs, sharps precautions, and a biosafety manual defining any needed waste decontamination or medical surveillance policies. 

Note Some states define decontaminated surety material as a RCRA Hazardous Waste. 

Considering the fundamental notions developed above, what conclusions can be stated using these theoretical and experimental data in order to define an optimal process for the decontamination of an ocular chemical projection ... 

There are certain unique features to the chemical separations used in radiochemistry compared to those in ordinary analytical chemistry that are worth noting. First of all, high yields are not necessarily needed, provided the yields of the separations can be measured. Emphasis is placed on radioactive purity, expressed as decontamination factors rather than chemical purity. Chemical purity is usually expressed as the ratio of the number of moles (molecules) of interest in the sample after separation to the number of all the moles (molecules) in the sample. Radioactive purity is usually expressed as the ratio of the activity of interest to that of all the activities in the sample. The decontamination factor is defined as the ratio of the radioactive purity after the separation to that prior to the separation. Decontamination factors of 105-107 are routinely achieved with higher values possible. In the event that the radionuclide(s) of interest are short-lived, then the time required for the separation is of paramount importance, as it does no good to have a very pure sample in which most of the desired activity has decayed during the separation. 

Another type of classification is outlier selection or contamination identification. As an example, in Fig. 4.23(b), the butter is the desired material and bacteria the contamination. An arbitrary threshold for this image would be 0.02, in which all pixels >0.02 are considered suspect, and hopefully, because this is a food product, decontamination procedures are pursued. In these two examples of classification, only arbitrary thresholds have been defined and, as such, confidence in these classifications is lacking. This confidence can be achieved through statistical methods. Although this chapter is not the appropriate place for an involved discussion of application of statistics toward data analysis, we will give one example often used in chemometric classification. 

The Army also uses the designations 0, IX, 3X, or 5X (defined in Box 3-1) to characterize and classify the agent contamination level of exposed materials. These nonanalytical designations reflect the decontamination treatment a specific waste has received. 

NECDF management defined decontamination levels as X = agent-contaminated waste with VSL >0.7 STEL 3X = agent-contaminated waste with VSL <0.7 STEL 5X = waste decontaminated completely when subjected to procedures known to completely degrade the agent molecule (such as 1000°F for 15 minutes). 

At TOCDF, treated scrap metal must be managed as a hazardous waste until verification testing has been accepted. Treated scrap metal is defined in the permit as metal from bulk containers, projectiles, and mortar rounds that has undergone thermal decontamination in the MPF under normal operating parameters and has no residue, internally or externally. Before shipment of treated scrap metal, residue in the interior and on... 

The mixture was tested in the guinea pig model, where fur was shaved on the side of the animal one day before exposing the skin of the anesthetized animals to neat GD or VX (Lukey et al, 2004). The animals were decontaminated 1 min later with sterile gauze soaked in the combined solution in a defined manner the contaminated side was wiped across the exposure site in the direction of the shaved... 

For the treatment of low and intermediate level wastes, three processes are generally adopted, namely, chemical precipitation, ion exchange, and evaporation. The efficiency of the treatment scheme is judged by the values of decontamination factor (DF) and volume reduction factors (VRFs), which are defined as follows ... 

All potential points of leaks and other hot spots have to be identified in the stage of design. The decontamination procedures in case of accident have to be elaborated. The specification of the equipment for eventual decontamination and the means of decontamination are defined in laboratory instructions and manuals. All necessary safeguards and security systems are the elements of the project design. In case of emergency all means limiting the decontamination spreading out have to be used. 

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