Chemistry Lab Safety Manual

This section was last updated on 9/26/07.

Housekeeping

The laboratory should be kept clean and free from clutter, by regular maintenance. At the completion of each experiment, equipment should be cleaned and properly stored. Do not let unused equipment or chemicals accumulate in the lab. Do not use the aisles of the lab or the space in front of the emergency escape panels for storage. Dispose of all hazardous wastes in accord with the procedures indicated in this manual.

Reagent bottles must be properly labeled - when pouring hold the bottle with its label to your palm to protect the label. Notify your safety officer of bottles whose contents are in doubt.

Hygiene

Wash hands often--always before eating, smoking, or leaving the laboratory. Washing should be an instinctive reaction to spillage of any chemical on the skin.

Never eat or drink in the lab - never use lab equipment as a food or drink container.

No food items should ever be stored or even cooled in a laboratory refrigerator. Food and beverages can become contaminated within a very short period of time to a life-threatening level by absorption of chemical vapors. Any food/beverage found in inappropriate areas will be removed without notice.

For more information see the OESO Laboratory Safety Manual discussion on chemical hygiene at the following URL. http://www.safety.duke.edu/SafetyManuals/LabManual/section2.htm#Chemical Hygiene

Eye Protection

Various types of eye protection listed in order of increasing effectiveness include:

Chemistry Department policy requires that all persons wear, at least, safety glasses (equipped with side shields), or goggles for eye protection while in the laboratory. In situations in which there is potential of a corrosive chemical being splashed into the eyes, safety glasses or goggles AND a face shield are required. In situations where there is potential for an explosion to occur, head shields are required in addition to safety glasses or goggles.

Department policy on contact lenses in the laboratory is that you may wear contact lenses, but only if your eyes are protected as described in the preceding paragraph by safety glasses or goggles, with or without a face or head shield. Normal eye protection is required when you are wearing contact lenses since contact lenses provide little to no protection from chemicals in the eye. (In fact, contact lenses can complicate flooding the eye with water should a chemical get in the eye.)

Plain lens safety glasses, with side shields are provided for chemistry employees (including all research students and teaching assistants) at no charge. An authorization slip from the Chemistry Office (room 3236) should be taken to the Chemistry Department Stockroom. Prescription safety glasses are available (at your expense) through a local optometrist.

Students who wear prescription glasses, and who do not wish to wear safety goggles available at Bryan Center Store, must cover the costs involved in being fitted with prescription safety glasses.

Available in the Chemistry Department Stockroom and at the Bryan Center are safety glasses which all undergraduates are expected to purchase and wear at all times when they are working at their laboratory benches or in any area where hazardous activities could endanger their eyes. Teaching Assistants and faculty supervising them are expected to enforce this regulation at all times. Teaching Assistants are reminded that the safety performance of classes under their regulation is one of the criteria by which they will be evaluated by the faculty.

Foot Protection

All persons in labs must wear shoes (bare feet or sandals are not allowed) and adequate clothing to protect the skin from spilled chemicals.

Skin Protection

Always wear clothing that minimizes the amount of skin that can be exposed to potentially harmful chemicals. Never wear shorts in the lab.

Of the ways chemicals can affect the human body, exposure through skin contact is one of the most significant. The skin does a wonderful job acting as a barrier to those conditions normally encountered in the environment; however, as our workplace environments use more and more chemical substances, our skin can no longer provide adequate protection on its own.

A chemical may cause damage by more than one of the above effects. Some examples include chlorinated solvents, such as ethylene dichloride, which will defat the skin causing irritation and tissue breakdown, also can permeate the skin possibly causing liver and kidney damage.

Hand Protection

Our hands are the body parts most likely to be exposed to chemical contact under normal situations. Even though careful technique may help an employee avoid direct contact with a chemical; the potential for exposure still demands the use of protective gloves. The department of Chemistry maintains a small list of glove compatibilities at the following URL: http://www.chem.duke.edu/safety/glove.html. These charts are by no means complete. If you have any questions regarding the effectiveness of a glove with a specific chemical, contact OESO or visit the following glove manufacturer links:

"Karen E. Wetterhahn, professor of chemistry.... in the the Sciences at Dartmouth College, died June 8 at age 48 from mercury poisoning....While preparing the mercury NMR standard in a fume hood, Wetterhahn spilled one to a few drops of dimethylmercury. The compound permeated the latex gloves she was wearing and was absorbed through her skin into the bloodstream." C & EN, June 16, 1997, page 12.

In choosing a glove that will provide an adequate level of protection, it is important to keep three warnings in mind:

All chemicals will permeate through all glove materials. This process involves absorption of the chemical at the outside surface, diffusion of the chemical through the glove, and then desorption of the chemical from the inside of the glove. Gloves are considered protective if the rate of this permeation process is slow enough that the chemical does not break through to the inside.

Glove manufacturers use two measures of glove suitability: Permeation Rate; the amount of a chemical which is passed through a given area of glove material per unit time and Breakthrough Time; the elapsed time from initial contact of the chemical to the outside of the glove to the first detection of the chemical on the inside glove surface. The objective in choosing a glove should be to seek a low permeation rate and a high breakthrough time, keeping in mind some of these factors:

There are many other factors that must be considered when selecting the glove that best suits the task. In some cases, your task may require you to choose a glove material which has a higher permeation rate, but has other qualities which makes it better for your situation. Some of these factors include:

The intent of this article was to present an overview of the complex nature of selecting the correct glove for adequate protection. Users should consult chemical MSDS's, glove manufacturer's literature, and the OESO for assistance.

Respiratory Protection Equipment

Fume hoods provide constant respiratory protection in all laboratories in the building. Such protection is adequate for most controlled experiments. In using the hoods in the building, the following facts should be kept in mind.

What does that gauge on my chemical hood mean? (This section is being checked for accuracy.)

The chemical fume hoods in the Department have been fitted with digital meters that provide the face velocity of airflow in feet per minute or FLO. FLO indicates the hood sash is fully closed so there is no face velocity. Makeup air is still being exhausted from the hood, but its velocity is not indicated on the guage. These gauges allow employees to check that the hood is functioning properly (i.e., have a minimum face velocity of 75 ft/min) every time they use the chemical hood. If a hood is not functioning properly, it should not be used and employees should call maintenance. Also place a sign on the hood so that others will not use it.

Respiratory protection equipment for emergency use.

There are two types of emergency equipment available for respiratory protection: air-purifying and self-contained. These should only be used by Safety Office Personnel or others who have been instructed in their use. If you have need of respiratory protection equipment, contact the OESO.

General Safety Equipment Available in Each Lab

If you use any of the expendable safety items (such as a fire extinguisher), notify the OESO at 684-2794 as soon as possible so that replacements can be obtained.

Spill Kit -Adjacent to the ice machine on the first level (hallway near 1112) there are spill kits for handling common spills involving 1) Solvents, 2) Acids (not for use with HF spills) and 3) Caustics. Directions for the use of each kit are provided with each kit. If you use one of these kits, notify the Lab Preparator (x1517, Room 1214) so that the used kit will be replaced. The used materials from the kit are to be kept in your lab (in a hood) and are to be treated as a hazardous waste. It is necessary to fill out a form requesting that this waste be removed from your lab by the OESO. (See the section dealing with disposal of waste chemicals later in this manual.)