Hazards cross-contamination

Minimize contamination via fewer cross-connections and fewer hose stations. Minimize the number of hoses required in loading/un-loading facilities. Cross-contamination, sometimes even from catalytic amounts of material, can result in undesired hazardous reactions. To prevent contamination due to rainwater and spills, consider storing a material that can react vigorously with water under a roof. 

Adequacy of cleaning out, and removal of residues from, the previous chemical carried to avoid cross-contamination and potential reactive hazards on refilling. 

The samples should be stored so that there is no hazard to laboratory staff. The integrity of the sample must also be preserved, i.e. the sample should be the same when it is analysed as when it was collected. There must be no risk of contamination or cross-contamination , i.e. no material should enter or leave the sample container. In addition, extremes of environmental conditions should be avoided. 

Small areas Extreme care must be exercised when dealing with dry or powdered agents as toxins may adhere to the skin or clothing and then be spread to other areas. Because of the minute quantities needed to produce a response in an exposed individual, cross contamination can pose a significant inhalation or puncture hazard later. 

Normal routes of transmission Cross contamination Airborne (Unknown mechanism). Secondary Hazards Mechanical Vectors (planting, harvesting, track out, possibly insects) Crop debris. 

A thorough understanding of the potential hazards of the substances involved and the process is essential, particularly taking into account the possibility of cross-contamination am interaction matrix is a useful tool to obtain the needed information. 

Heating, ventilation, and air conditioning (HVAC) is a very expensive utility. However, it is essential and serves a variety of purposes. Not only is it important to maintain constant temperature and humidity, it is also important to balance the pressure in the processing areas to minimize cross-contamination opportunities. Dust collection, as mentioned earlier, is very important when handling powders. The dust generated during some processes may be toxic and may pose an explosion hazard. This system is typically very closely associated with the HVAC system. 

At tracer levels the radiation hazard is slight but the contamination hazard is ever present. Cross-contamination of low activity samples by apparatus previously used for samples of a higher activity is probably the worst hazard and must constantly be guarded against. 

Improved housekeeping at waste generation sources could reduce the waste shipped offsite. Cross-contamination (mixing of nonhazardous waste with hazardous waste or vice versa) results in larger quantities of hazardous waste than are actually generated. Elimination of this would help achieve savings on disposal cost. 

Spillages should be cleaned as soon as possible to prevent possible contamination, cross-contamination and hazards. Written procedures should be in place for the handling of such occurrences. 

It has already been noted in Section 2.4.1 that authentic compounds may need to be synthesized by the laboratory which also carries out analysis. Whereas this is a convenient — and indeed desirable — activity, the possibility of cross-contamination should not be underestimated. It is clearly hazardous for an analyst working with possibly nanograms of a compound to be in the close vicinity of a synthetic chemist producing gram quantities of the same substance. These two operations should therefore be separated, and particular care should be given to the design of, and access to the facility in which synthesis is carried out (Alexander et al. 1986). The operation of the... 

The purity of solvents should not be taken for granted, and if redistillation is practiced, this should be carried out in a stream of N2 to eliminate contamination by volatile laboratory contaminants cross-contamination is a potentially serious problem and steps should be taken to ensure that samples, standards, and solvents are not exposed to this hazard. 

In order to minimize the risk of a serious medical hazard due to cross-contamination, dedicated and self-contained faaTrties must be available for the production of particular pharmaceutical products, such as highly sensitizing materials (e.g., penicillins) or biological preparations (e.g., live microorganisms). The production of certain other products, such as some antibiotics, hormones, cytotoxic substances, highly active pharmaceutical products, and non-pharmaceutical products, should not be conducted in... 

The manufacturing and handling of radiopharmaceuticals is potentially hazardous. The types of radiation emitted and the half-lives of the radioactive isotopes are parameters contributing to the level of risk. Particular attention must be paid to the prevention of cross-contamination, to the retention of radionuclide contaminants, and to waste disposal. Special consideration may be necessary with reference to the small batch sizes made frequently for many radiopharmaceuticals. Due to their short half-life some radiopharmaceuticals are released before completion of certain Quality Control tests. In this case, the continuous assessment of the effectiveness of the Quality Assurance system becomes very important. 

---