SAFETY and EQUIPMENT for CLINICAL CHEMISTRY LABs

PERSONNEL SAFETY in CLINICAL CHEM LABs

Safety Responsibility

The employer and the employee share safety responsibility. The employer has the ultimate responsibility for safety and delegates authority for safe operations to supervisors. Safety management in the laboratory should start with a written safety policy. Laboratory supervisors, who reflect the attitudes of management toward safety, are essential members of the safety program.

Employer's Responsibilities:

¦ Establish laboratory work methods and safety policies.

¦ Provide supervision and guidance to employees.

¦ Provide safety information, training, personal protective equipment, and medical surveillance to employees.

¦ Provide and maintain equipment and laboratory facilities that are adequate for the tasks required.

The employee also has a responsibility for his or her own safety and the safety of coworkers. Employee con duct in the laboratory is a vital factor in the achievement of a workplace without accidents or injuries.

Employee's Responsibilities:

¦ Know and comply with the established laboratory work safety methods.

¦ Have a positive attitude toward supervisors, co-workers, facilities, and safety training.

¦ Give prompt notification of unsafe conditions or practices to the immediate supervisor and ensure that un safe conditions and practices are corrected.

¦ Engage in the conduct of safe work practices and use of personal protective equipment.

Signage and Labeling

Appropriate signs to identify hazards are critical, not only to alert laboratory personnel to potential hazards, but also to identify specific hazards that arise because of emergencies such as fire or explosion. The National Fire Protection Association (NFPA) developed a standard hazards-identification system (diamond-shaped, color coded symbol), which has been adopted by many clinical laboratories. At a glance, emergency personnel can assess health hazards (blue quadrant), flammable hazards (red quadrant), reactivity/stability hazards (yellow quadrant), and other special information (white quadrant). In addition, each quadrant shows the magnitude of severity, graded from a low of 0 to a high of 4, of the hazards within the posted area. (Note the NFPA hazard-code symbol in ___1.) Manufacturers of laboratory chemicals also provide precautionary labeling information for users. Information indicated on the product label includes statement of the hazard, precautionary measures, specific hazard class, first aid instructions for internal/external contact, the storage code, the safety code, and personal protective gear and equipment needed. This information is in addition to specifications on the actual lot analysis of the chemical constituents and other product notes. All in house prepared reagents and solutions should be labeled in a standard manner and include the chemical identity, concentration, hazard warning, special handling, storage conditions, date prepared, expiration date (if applicable), and preparer's initials.

LAB SAFETY EQUIPMENT

Safety equipment has been developed specifically for use in the clinical laboratory. The employer is required by law to have designated safety equipment available, but it’s also the responsibility of the employee to comply with all safety rules and to use safety equipment.

All laboratories are required to have safety showers, eyewash stations, and fire extinguishers and to periodically test and inspect the equipment for proper operation. It’s recommended that safety showers deliver 30 to 50 gallons of water per minute at 20 to 50 psi. Other items that must be available for personnel include fire blankets, spill kits, and first aid supplies.

Mechanical pipetting devices must be used for manipulating all types of liquids in the laboratory, including water. Mouth pipetting is strictly prohibited.

Chemical Fume Hoods and Biosafety Cabinets

Fume Hoods

Fume hoods are required to expel noxious and hazardous fumes from chemical reagents. Fume hoods should be visually inspected for blockages. A piece of tissue paper placed at the hood opening will indicate air flow direction. The hood should never be operated with the sash fully opened. Chemicals stored in hoods should not block airflow. Periodically, ventilation should be evaluated by measuring the face velocity with a calibrated velocity meter. The velocity at the face of the hood (with the sash in normal operating position) must be 100 to 120 feet per minute. Smoke testing is also recommended to locate no flow or turbulent areas in the working space. Additional monitoring should be in accordance with the chemical hygiene plan of the facility.

___-1. Sample chemical label: (1) statement of hazard; (2) hazard class; (3) safety precautions; (4) National Fire Protection Agency (NFPA) hazard code; (5) fire extinguisher type; (6) safety instructions; (7) formula weight; and (8) lot number.

Color of the diamond in the NFPA label indicates hazard:

• Red _ flammable. Store in an area segregated for flammable reagents.
• Blue _ health hazard. Toxic if inhaled, ingested, or absorbed through the skin. Store in a secure area.
• Yellow _ reactive and oxidizing reagents. May react violently with air, water, or other substances. Store away from flammable and combustible materials.
• White _ corrosive. May harm skin, eyes, or mucous membranes. Store away from red-, blue-, and yellow-coded reagents.
• Gray _ presents no more than moderate hazard in any of categories. For general chemical storage.

Exception _ reagent incompatible with other reagents of same color bar. Store separately. Hazard code (4)-Following the NFPA use, each diamond shows a red segment (flammability), a blue segment (health; i.e., toxicity), and yellow (reactivity). Printed over each color-coded segment is a black number showing the degree of hazard involved. The fourth segment, as stipulated by the NFPA, is left blank. It’s reserved for special warnings, such as radioactivity. The numeric ratings indicate degree of hazard: 4 _ extreme; 3 _ severe; 2 _ moderate; 1 _ slight; and 0 _ none according to present data.

Biosafety Cabinets

Biohazard hoods remove particles that may be harmful to the employee who is working with infective biologic specimens. The Centers for Disease Control and Prevention (CDC) and the National Institutes of Health have described four levels of biosafety, which consist of combinations of laboratory practices and techniques, safety equipment, and laboratory facilities. The biosafety level of a laboratory is based on the operations performed, the routes of transmission of the infectious agents, and the laboratory function or activity.

Accordingly, biosafety cabinets are designed to offer various levels of protection, depending on the biosafety level of the specific laboratory.

Chemical Storage Equipment

Safety equipment is available for the storage and handling of chemicals and compressed gases. Safety carriers should always be used to transport 500-mL bottles of acids, alkalis, or other solvents, and approved safety cans should be used for storing, dispensing, or disposing of flammables in volumes greater than 1 quart. Safety cabinets are required for the storage of flammable liquids, and only specially designed, explosion-proof refrigerators should be used to store flammable materials. Only the amount of chemical needed for that day should be available at the bench. Gas-cylinder supports or clamps must be used at all times, and large tanks should be transported using handcarts.

Personal Protective Equipment

The parts of the body most frequently subject to injury in the clinical laboratory are the eyes, skin, and respiratory and digestive tracts. Hence, the use of PPE is very important. Safety glasses, goggles, visors, or work shields protect the eyes and face from splashes and impact.

Contact lenses don’t offer eye protection; it’s strongly recommended that they not be worn in the clinical chemistry laboratory. If any solution is accidentally splashed into the eye(s), thorough irrigation is required.

Gloves and rubberized sleeves protect the hands and arms when using caustic chemicals. Gloves are required for routine laboratory use; however, polyvinyl or other non-latex gloves are an acceptable alternative for people with latex allergies. Certain glove materials offer better protection against particular reagent formulations.

Nitrile gloves, for example, offer a wider range of compatibility with organic solvents than do latex gloves. Lab coats, preferably with knit-cuffed sleeves, should be full length and buttoned and made of liquid-resistant material. When performing manipulations prone to splash hazards, the lab coat should be supplemented with an impermeable apron and/or sleeve garters, constructed of suitable material to guard against the substances. Proper footwear is required; shoes constructed of porous materials, open-toed shoes, or sandals are considered ineffective against spilled hazardous liquids.

Respirators may be required for various procedures in the clinical laboratory. Whether used for biologic or chemical hazards, the correct type of respirator must be used for the specific hazard. Respirators with high efficiency particulate air (HEPA) filters must be worn when engineering controls are not feasible, such as when working directly with patients with tuberculosis (TB) or when performing procedures that may aerosolize specimens of patients with a suspected or confirmed case of TB. Training, maintenance, and written protocol for use of respirators are required according to the respiratory protection standard.

Each employer must provide (at no charge) lab coats, gloves, or other protective equipment to all employees who may be exposed to biologic or chemical hazards. It’s the employer's responsibility to clean and maintain all PPE. All contaminated PPE must be removed and properly disposed of before leaving the laboratory.

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COMPARISON OF BIOLOGIC SAFETY CABINETS

CABINETS | APPLICATIONS

TYPE: Class I,* open front Class II Type A Type B1 Type B2 Type B3 Class III

FACE VELOCITY (IFPM): 75 -- 75 100 100 100 NA

AIRFLOW PATTERN:

In at front; rear and top through HEPA filter; 70% Recirculated through HEPA; exhaust through HEPA; 30% Recirculated through HEPA; exhaust via HEPA and hard-ducted

No recirculation; total exhaust via HEPA and hard-ducted

Same as IIA, but plenums under negative pressure to room and exhaust air is ducted

Supply air inlets and exhaust through 2 HEPA filters

RADIONUCLIDES/ TOXIC CHEMICALS: No No Yes 2 (low levels/volatility) Yes Yes Yes

BIOSAFETY LEVEL(S): 2, 3--2, 3--2, 3--2, 3--2, 3--3, 4

PRODUCT PROTECTION: No—Yes—Yes—Yes--Yes

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