Safety Standards and Agencies

Safety standards for clinical laboratories are initiated, governed, and reviewed by several agencies or committees. These include the following:

The primary purpose of OSHA standards is to ensure safe and healthful working conditions for every U.S. worker. To ensure that workers have safe and healthful working conditions, the federal government passed the Occupational Safety and Health Act of 1970 and, in 1988, expanded the Hazard Communication Standard to apply to hospital staff. Occupational Safety and Health Act regulations apply to all businesses with one or more employees and are administered by the U.S. Department of Labor through OSHA. The programs deal with many aspects of safety and health protection, including compliance arrangements, inspection procedures, penalties for noncompliance, complaint procedures, duties and responsibilities for administration and operation of the system, and how the standards are set. Responsibility for compliance is placed on the administration of the institution and the employee.

OSHA standards, where appropriate, include provisions for warning labels or other appropriate forms of warning to alert all workers to potential hazards, suitable protective equipment, exposure control procedures, and implementation of training and education programs. In 1991, OSHA mandated that all clinical laboratories must implement a chemical hygiene plan and an exposure control plan. As part of the chemical hygiene plan, a copy of the material safety data sheet (MSDS) must be on file and readily accessible and available to all employees at all times. The MSDS describes hazards, safe handling, storage, and disposal of hazardous chemicals. Information is provided by chemical manufacturers and suppliers about each chemical and accompanies the shipment of each chemical. Each MSDS contains basic information about the specific chemical or product, including its trade name, chemical name and synonyms, chemical family, manufacturer’s name and address, emergency telephone number for further information about the chemical, hazardous ingredients, physical data, fire and explosion data, and health hazard and protection information. The MSDS describes the effects of overexposure or exceeding the threshold limit value of allowable exposure for an employee in an 8-hour day. The MSDS also describes protective personal clothing and equipment requirements, first aid practices, spill information, and disposal procedures.

In 2006, the CDC introduced the National Healthcare Safety Network (NHSN). This voluntary system integrates a number of surveillance systems and provides data on devices, patients, and staff. Many hospitals have reorganized the physical layout of handwashing stations (see later, “Handwashing”) to prevent the spread of pathogens.

Adherence to general safety practices will reduce the risk of inadvertent contamination with blood or body fluids, as follows:

Each laboratory must have an up to date safety manual. This manual should contain a comprehensive listing of approved policies, acceptable practices, and precautions, including Standard Blood and Body Fluid Precautions. Specific standards that conform to current state and federal requirements (e.g., OSHA regulations) must be included in the manual.

Prevention of Transmission of Infectious Diseases

According to the CDC concept of Standard Precautions, all human blood and other body fluids are treated as potentially infectious for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and other blood-borne microorganisms that can cause disease in human beings. Compliance with the OSHA Bloodborne Pathogens Standard and the Occupational Exposure Standard is required to provide a safe work environment. OSHA mandates that the employer do the following:

Blood is the most important source of HIV, HBV, and other bloodborne pathogens in the occupational setting. HBV can be present in extraordinarily high concentrations in blood, but HIV is usually found in lower concentrations. HBV may be stable in dried blood and blood products at 25° C for up to 7 days. HIV retains infectivity for more than 3 days in dried specimens at room temperature and for more than 1 week in an aqueous environment at room temperature.

Both HBV and HIV may be transmitted indirectly. Viral transmission can result from contact with inanimate objects, such as work surfaces or equipment contaminated with infected blood or certain body fluids. If the virus is transferred to the skin or mucous membranes by hand contact between a contaminated surface and nonintact skin or mucous membranes, it can produce viral exposure.

Medical personnel must remember that HBV and HIV are different diseases caused by unrelated viruses. The most feared hazard of all, the transmission of HIV through occupational exposure, is among the least likely to occur. The modes of transmission for HBV and HIV are similar, but the potential for transmission in the occupational setting is greater for HBV than HIV.

The transmission of hepatitis B can also be fatal and it is more probable than transmission of HIV. The number of cases of acute hepatitis among health care workers because of occupational exposure has sharply declined since hepatitis B vaccine became available in 1982. The likelihood of infection in health care workers after exposure to blood infected with HBV or HIV depends on the following factors:

Both HBV and HIV may be directly transmitted by various portals of entry. In the occupational setting, however, the following situations may lead to infection:

Most exposures do not result in infection. The risk varies not only with the type of exposure but also with the amount of infected blood in the exposure, the length of contact with the infectious material, and the amount of virus in the patient’s blood or body fluid or tissue at exposure. Studies have reported that the average risk of HIV transmission is approximately 0.3% after percutaneous exposure to HIV-infected blood and 0.09% after mucous membrane exposure.

Safe Work Practices for Infection Control

The use of CDC Standard Precautions is an approach to infection control that prevents occupational exposures to blood-borne pathogens. It eliminates the need for separate isolation procedures for patients known or suspected to be infectious. The application of Standard Precautions also eliminates the need for warning labels on specimens.

OSHA requires laboratories to have a personal protective equipment (PPE) program. The components of this regulation include the following:

Laboratory personnel should not rely solely on PPE to protect themselves against hazards. They should also apply PPE standards when using various forms of safety protection.

A clear policy on institutionally required Standard Precautions is needed. For usual laboratory activities, PPE consists of gloves and a laboratory coat or gown; other equipment such as masks would normally not be needed. Standard Precautions are intended to supplement rather than replace handwashing recommendations for routine infection control. The risk of nosocomial transmission of HBV, HIV, and other bloodborne pathogens can be minimized if laboratory personnel are aware of and adhere to essential safety guidelines.

Gloves for medical use are sterile surgical or nonsterile examination gloves made of vinyl or latex. There are no reported differences in barrier effectiveness between intact latex and intact vinyl gloves. Tactile differences have been observed between the two types of gloves, with latex gloves providing more tactile sensitivity; however, either type is usually satisfactory for phlebotomy and as a protective barrier during technical procedures. Latex-free gloves should be available for personnel with sensitivity to usual glove material. Rubber household gloves may be used for cleaning procedures.

General guidelines related to the selection and general use of gloves include the following:

Care must be taken to avoid indirect contamination of work surfaces or objects in the work area. Gloves should be properly removed (Fig. 6-1) or covered with an uncontaminated glove or paper towel before answering the telephone, handling laboratory equipment, or touching doorknobs.

Handwashing

Frequent handwashing is an important safety precaution. It should be performed after contact with patients and laboratory specimens (Box 6-1). Gloves should be used as an adjunct to, not a substitute for, handwashing.