6.C.2.6.2 Clothing and Protective Apparel
Protective clothing should be used when there is significant potential for skin-contact exposure to chemicals. Protective clothing does not offer complete protection to the wearer and should not be used as a substitute for engineering controls. The protective characteristics of any protective clothing must be matched to the hazard. As with gloves, no single material that provides protection to all hazards is available. When multiple hazards are present, multiple layers of protective clothing may be required. Some types of PPE, such as aprons of reduced permeability and disposable laboratory coats, offer additional safeguards when working with toxic materials. (See also Chapter 7, section 7.F.1.1)
Commercial lab coats are fabricated from a variety of materials, such as cotton, polyester, cotton-polyester blends, polyolefin, and polyaramid. Selection of the proper material to deal with the particular hazards present is critical. For example, although cotton is a good material for laboratory coats, it reacts rapidly with acids. Plastic or rubber aprons can provide good protection from corrosive liquids but can be inappropriate in the event of a fire. Because plastic aprons can also accumulate static electricity, they should not be used around flammable solvents, explosives sensitive to electrostatic discharge, or materials that can be ignited by static discharge. Because many synthetic fabrics are flammable and can adhere to the skin, they increase the severity of a burn and should not be worn if working with flammable materials or an open flame. When working with flammable materials or pyrophorics, use laboratory coats made from flame-resistant, nonpermeable materials (polyaramids). Disposable garments may be a good option if handling carcinogenic or other highly hazardous materials. However, these provide only limited protection from vapor or gas penetration. Take care to remove disposable garments without exposing any individual to toxic materials and dispose of as hazardous waste.
To prevent chemical exposure from spilled materials in the laboratory, wear shoes that cover the entire foot. Perforated shoes, open-toe and open-heel shoes, sandals, or clogs should not be permitted. Shoes should have stable soles that provide traction in slippery or wet environments to reduce the chance of falling. Socks should cover the ankles so as to protect against chemical splashes. High heels should not be worn in the laboratory.
Once they have been used, laboratory coats and other protective apparel may become contaminated. Therefore, they must be stored in the laboratory and not in offices or common areas. Institutions should provide a commercial laundry service for laboratory coats and uniforms; they should not be laundered at home.
A definite correlation exists between orderliness and the level of safety in the laboratory. In addition, a disorderly laboratory can hinder or endanger emergency response personnel. The following housekeeping rules should be adhered to:
• Never obstruct access to exits and emergency equipment such as fire extinguishers and safety showers. Comply with local fire codes for emergency exits, electrical panels, and minimum aisle width.
• Store coats, bags, and other personal items in the proper area, not on the benchtops or in the aisles.
• Do not use floors, stairways, and hallways as storage areas. Items stored in these areas can become hazards in the event of an emergency.
• Keep drawers and cabinets closed when not in use, to avoid accidents.
• Label transfer vessels2 with the full chemical name, manufacturer’s name, hazard class, and any other special warnings.
• Store chemical containers in order and neatly. Face labels outward for easy viewing. Containers themselves should be clean and free of dust. Containers and labels that have begun to degrade should be replaced, repackaged, or disposed of in the proper location. Do not store materials or chemicals on the floor because these may present trip and spill hazards.
• Keep chemical containers closed when not in use.
• Secure all water, gas, air, and electrical connections in a safe manner.
• Return all equipment and laboratory chemicals to their designated storage location at the end of the day.
• To reduce the chance of accidentally knocking containers to the floor, keep bottles, beakers, flasks, and the like at least 2 in. from the edge of benchtops.
• Keep work areas clean (including floors) and uncluttered. Wipe up all liquid and ice on the floor promptly. Accumulated dust, chromatography adsorbents, and other chemicals pose respira-
2Transfer vessels may also be known as “secondary containers.” The term “transfer vessel” is used here to avoid confusion with secondary containment, which is a tray, bucket, or other container used to control spills from a primary container in the event of breakage.