Biohazards practices

Sometimes in the design of a BSL-4 facility, the full letter of health and safety codes/requirements for the protection of workers can not be met. This is where health and safety specialists must compromise and use their ingenuity to meet the intent of the requirements. For example, it is not always possible to provide a secondary means of egress from each area. Two change facilities are not cost effective or practical. A viable alternative is the use of airlocks with built-in liquid disinfection systems which are not hazardous to humans, but destroy the biohazard. These airlocks must be clearly identified as others are often used for transportation of equipment and other materials and contain hazardous disinfection systems. 

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. 

As indicated below, toxin and contaminated materials that are intended for disposal should be handled as a biohazard and, whenever practical, treated to abolish toxicity. 

BSL-1 practice plus Limited access Biohazard warning signs waste decontamination or medical surveilkmce policies... 

A consensus code of practice for controlling biohazards. Biosafety in Microbiological and Biomedical Laboratories, was first produced by the Centers for Disease Control and Prevention and the National Institutes of Health in 1984 the third and most recent edition was published in 1993 (U.S. DHHS, 1993). 

Prudent practices for working with radioactive materials are similar to those needed to reduce the risk of exposure to toxic chemicals (section 5.C has similar information) and to biohazards ... 

Employers should take appropriate preventative measures against occupational exposure. These include engineering controls and work practice controls. Examples of engineering controls include biohazard hoods, puncture-resistant sharps containers, mechanical pipette devices, and other devices that permanently remove the hazard or isolate individuals from exposure. Organizations must evaluate and incorporate new safer devices including needleless devices, needles with sheaths, and blunt suture needles. Work practice controls must include hand washing policies, sharps handling procedures, proper waste disposal techniques, and other actions that would reduce the likelihood of exposure. 

Spring 1989, Northeastern US. Investigative reporters discovered a new source of potential food contamination. When trucking companies that hauled food from the Midwest to the East Coast traveled back in the other direction, some hauled garbage from eastern cities to Midwest landfills. The practice was known as cross-hauling. There was a concern whether food might become contaminated with biohazards. 

Research the scope of biohazard problems in the world, particularly developing countries that have poor water supplies, limited sanitary sewers, and treatment plants. Identify practices that lead to biohazard infections and illnesses. Identify ways to minimize these hazards. 

Best practices from the pharmaceutical industry were applied in the design of the biological areas, such as the separation of bacterial laboratories from cell-culture laboratories. Handwashing stations—completely hands-free— were built into the entrance and exit areas of the BSL-2+ laboratories. Ultraviolet (UV) sanitization lights were incorporated into the room design, with appropriate door interlocks and window coverings. Full-exhaust biosafety cabinets were accommodated for all biohazard work. 

Compliance with biohazard and chemical waste management regulations continues to be one of the most significant issues in any laboratory. Chemical waste, either stock or reagent, should never be poured down laboratory drains. Instead, it should be collected into appropriate and clearly identified ( HAZARDOUS WASTE ) containers prior to removal by waste management services. Chemicals and reaction products should never be mixed. Not only is the practice dangerous but also creates additional costs in terms of dealing with the waste. 

The basic facility usually consists of a general laboratory with certain design features and operational practices intended to limit the possibility of exposure to and release of biohazardous agents. However, no containment equipment is required and specialized ventilation systems are unnecessary. The facility must be checked to be certain that it does indeed provide for sufficient control and containment of any agent to be used. 

Internal exposure to radiation can be controlled through careful laboratory practices and the most important ones are described below. Many of these practices are similar to those used for controlling biological hazards that were covered in Chapter 11. This is because many of the principles that apply to control of biohazards also apply to control of internal radiation exposure. 

In the past decade, new aetiologies of HP have been described in the field of agriculture. Although the relative humidity of hay or grain crops has been seen to decrease with better agricultural practice and education about biohazards, this change, paradoxically, does not imply a decrease in the frequency... 

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