A. Dressing for safety in the laboratory

Individuals should prepare for a safe laboratory experience by dressing appropriately for laboratory work. Appropriate clothing includes the following:

• Shoes should fully cover the feet to protect against spills; no open-toed shoes or sandals are permitted, and shoes with mesh inserts (such as athletic shoes) are not recommended. One may choose to keep a pair of sturdy leather shoes in the laboratory to change into upon arrival.

• Trousers or skirts falling below the knee are preferred; if shorter garments are worn, a lab coat or apron of below knee length is required. Preferred materials are resistant polyester, cotton or wool, since ordinary polyester and acrylics may be dissolved by common laboratory solvents.

• Neckties, if worn, should be firmly clipped to the shirt or confined inside a lab coat or apron.

• Loose, flowing garments and scarves should be avoided; they may easily pick up spills or trail through a burner flame.

• In a laboratory where open flames may be used, long hair should be confined.

• Loose jewelry should be avoided, since it may catch on equipment. Also avoid ornate rings that can damage protective gloves or make wearing or removing gloves difficult.

B. Protective Equipment

Every laboratory must have available, and workers must be trained in the use of, safety goggles, face masks, lab coats or aprons, gloves, and reaction shields.

1. Goggles that completely enclose the area of the eyes are required, rather than spectacles, to avoid the possibility of splashes running down the forehead into the eyes. They must be worn at all times when anyone in the laboratory is working with chemicals, as well as when an experiment is running unattended in the laboratory. The choice of specific type of goggle is left to the individual, except that goggles chosen must conform to ANSI standards for splash and impact resistance.

   Several spare pairs of goggles should be available for visitors, who are required to wear eye protection while in the laboratory.

   
   (A satisfactory type of protective goggle)

2. For work that poses a greater than ordinary danger of splashing or violent reaction, a hard face shield that protects the entire face as well as the eyes should be worn. Each laboratory must have at least one face shield available at all times. It is the responsibility of the laboratory workers and their supervisor to determine when this protection is needed.
   
   (A polycarbonate face shield)

3. After the face and eyes, the hands are the most vulnerable part of the body. Their protection should be routine. Disposable gloves may be used for ordinary laboratory operations such as recrystallizations, setting up equipment, and the like. Sturdier, less permeable gloves should be selected when working with strong acids or bases or other particularly hazardous materials. Nitrile gloves, such as those stocked by Central Supply, are preferred.

   In addition to disposable gloves, each laboratory should have available at least one pair of natural rubber gloves and one pair of Viton (or similar heavy, impermeable) gloves. Our stockroom will make these types available; individuals may special order other kinds as desired. Consult your MSDS or your glove safety chart (in the notebook with the hygiene plan) to select the appropriate pair for the materials with which you are working.

   1. Do not leave the laboratory while wearing protective gloves. Contaminants on the gloves can easily be transferred to doorknobs and other common objects. Remove and discard disposable gloves, and select a fresh pair upon returning to the lab.
   2. Note that gloves that are not disposable should be washed before they are removed!! These gloves also should be left in the laboratory.

   3. Insulated gloves (cryoscopic gloves) should be worn when handling liquefied gases or Dry Ice. A research group that makes extensive use of these materials should purchase a pair for the group, rather than constantly borrowing them from the stockroom.

4. Lab coats or aprons are worn to absorb or deflect spills and prevent corrosive or toxic substances from reaching the skin. Which is used is largely a matter of personal preference, but one or the other should be available to every individual working in a laboratory. The stockroom provides a basic cotton blend coat; however, individuals may choose to order coats of Tyvek, a spun, bonded polyester material made by DuPont, which is the best (most impermeable) material for these garments.

   Because coats and aprons are uncomfortable in hot weather, individuals often avoid their use. Although the best policy is to wear such protection at all times, its use may be limited to particularly hazardous operations such as use of strong acids, waste disposal, or accident cleanup.

5. Reaction shields are curved sheets of polycarbonate resin with lead bases, of such a size that they may be set up in front of a reaction to deflect violent splashes or glass fragments. They should be used whenever a potentially explosive reaction (such as one involving peroxides) or one involving especially corrosive materials (such as fluorosulfonic acid) is being conducted.
   
   (Two examples of reaction shields)

   Every laboratory should have at least one such shield of medium size.

Hoods, while typically classified as "engineering controls" for air quality, also are a form of personal protective equipment. Making proper decisions about when hoods should be used, and then using them safely, should be part of the planning for every experiment.

1. In research laboratories, almost all processes, save for recrystallizations from innocuous solvents, should be conducted in hoods.

2. Hoods must be kept uncluttered. Remove the equipment from one experiment before setting up another.

3. No part of the body save the hands and forearms should EVER be inside a hood. Leaning into the hood to obtain a better view places one's face in closer proximity to the experiment, and is particularly dangerous.

4. Keep the hood sash pulled down to the marked safe operating level at all times when not actually installing or removing equipment.