June 1994

Etiologic Agents Defined

Transporting of etiologic agents must meet strict Department of Transportation (DOT) regulations, which have been made known to all researchers. Basically, no one can ship a material which may contain an etiologic agent unless it has been packaged to withstand leakage of contents due to shocks, pressure changes, or handling.

The Center For Disease Control (CDC) defines an etiologic agent as a "viable microorganism or its toxin which causes, or may cause, human disease." The CDC has put out a lengthy list of etiologic agents, all of which must be shipped accordingly. Below is a partial listing of the more common etiologic agents.

Bacterial Agents:

  • All species Actinobacillus
  • All members Actinomycetoceae
  • All serotypes Arizona hinshawii
  • All species Bortonella
  • All species Bordetella
  • All species Brucella
  • All enteropathogenic serotypes Escherichia coli.
  • All species and sertypes Klebsiella
  • All species Legionella (and all Legionella-like organisms)
  • All serovars Leptospira interrogens
  • All species Listeria
  • All species Merexella
  • All species Mycobacterium
  • All species Mycoplasma
  • All species Pasteurella
  • All species and serotypes Salmonella
  • All species and serotypes Shigella
  • Viral Agents
  • All types human Adenoviruses
  • All types Arboviruses
  • All types Coxsackie A and B viruses
  • All types Dengus viruses
  • All types Echoviruses
  • Hepatitus-associated materials
  • All members Herpes virus
  • Infectious bronchitis-like virus
  • All types Influenza viruses
  • All types Parainfluenza viruses
  • All types Polloviruses
  • All members Poxviruses
  • All strains Rabies virus
  • All types Reoviruses
  • Respiratory syncytial viruses
  • All types Rhinoviruses
  • All species Rickettsia
  • All types Rolaviruses
  • Rubella virus
  • Yellow fever virus

A memo concerning the packaging and labeling of etiologic agents was sent out a few months ago to all researchers. DOES will package the agent for you, or we will train members of your lab in the proper protocol. If you have further questions concerning the packaging and labeling of etiologic agents, or if you are unsure if what you need to ship falls into this category, call DOES at x2907.

Laboratory Gloves: Are You Using the Right Ones?

Gloves are the single most common form of personal protective equipment in the lab. But if you are using gloves that are incompatible with certain chemicals, you may not be protecting yourself as well as you think. Several types of gloves are available and one kind may be more appropriate than another, depending on the job at hand.

Most gloves come in both single-use (or disposable) and reusable forms. Disposable gloves offer little protection against hazardous liquid materials and should only be used for non-toxic or non-hazardous materials. Reusable gloves offer more protection than disposables, so use the thicker gauge glove with more dangerous chemicals.

The most common types of gloves are made from:

  • Latex (or natural rubber)- Latex gloves are most common in disposable form, offering excellent conformity and dexterity. Therefore, they are good for quick jobs (when you only need gloves for a few minutes) and are resistant to most acids and alkalis.
  • Neoprene- Neoprene provides protection against a wide range of corrosive chemicals; it resists oils, greases, alcohols, resins, alkalis, and many solvents. It is poor for chlorinated aromatic solvents, phenols, and ketones.
  • Nitrile-Butadiene Rubber (NBR)- NBR gloves are marketed as SOL-VEX or Nitrile. These gloves work well with aromatic petroleum and chlorinated solvents. They are resistant to cuts, snags and punctures.
  • Vinyl- Vinyls are also popular in both disposable (thinner, examination-type gloves that allows precision in movement) and reusable forms (made of polyvinylchloride). The PVC glove is thicker and is necessary for use with corrosive materials. Where "vinyl" is listed on the chart below, use the PVC reusable gloves, not the thin disposables.

Below is an abbreviated chart showing some of the most commonly-used chemicals on campus and which glove is best for the job.

Chemical Best Glove Choice
Acetone latex, neoprene, or nitrile
Benzene nitrile
Chloroform nitrile
Chromic acid vinyl
Diethyl ether nitrile
Ethyl acetate neoprene or nitrile
Formaldehyde neoprene, nitrile, or vinyl
Hexane neoprene
Hydrochloric acid vinyl
Hydrofluoric acid vinyl
Methylene chloride nitrile
Nitric acid vinyl
Perchloric acid vinyl
Phenol neoprene or vinyl
Potassium/sodium hydroxide vinyl
Sulfuric acid latex, neoprene, or vinyl
Toluene nitrile

A more complete list can be found in the CWRU Chemical Safety Manual, Appendix D. Call the Department of Occupational and Environmental Safety (x2907) if you have further questions or if the chemical with which you are working is not listed in the Chemical Safety Manual.

Fire Safety on Campus: Prevention and Protection

At CWRU, the Department of Occupational and Environmental Safety is responsible for implementing and administering programs for fire safety and protection. The goal of these programs is to provide a campus environment that is as safe from fire hazards as reasonably possible. While every attempt is made to reduce fire hazards, possibility for fires still exists. Therefore, it is necessary to provide controls to minimize the potential for loss of life and/or injury in the event of a fire. This article will define some fire-related terms and will briefly discuss the prevention and protection programs in place on campus.

Fire Prevention

Fire safety involves two main areas: fire prevention and fire protection. Fire prevention concerns controlling flammable and combustible materials and sources of ignition (how much exists, where they are on campus, how they are handled, how they are stored). In order to prevent a fire, potential sources must be eliminated or contained. All fire prevention programs in place on campus strive to do these things, identify the fire hazards and either eliminate or reduce them.

Programs on campus designed to identify these hazards include: in-house DOES inspections, a building monitor program, and outside fire department inspections. Special attention is paid to high hazard areas (like laboratories) and resident halls.

Fire Protection

Fire protection takes over when prevention does not work. If prevention were 100% effective, protection would not be necessary. However, since this is not possible, protection systems are also in place. These systems can prevent a small fire from getting large and warn occupants of buildings of the fire. These protection systems include:

  • alarm systems which give occupants of university buildings "early warning" in the event of the fire. It is the university's policy to provide fire alarm systems in all buildings. These are installed to meet all state and local fire codes and are tested regularly in accordance with these codes. Alarm systems are tested twice per year by an outside service contractor, the records of which are on file with University Security.
  • portable fire extinguishers can also prevent small fires from getting large when handled by a person trained in its use. Each building is equipped with portable fire extinguishers that are inspected annually by an outside service contractor. Any extinguisher needing service will be removed and a replacement one will be put in its place. These records are on file in the DOES.
  • automatic fixed station fire extinguishing systems are provided for specific high hazards areas. These include cooking areas (dormitory or dining hall kitchens), areas where considerable amounts of flammable liquids are used, and places where highly complex and costly electronic or computer equipment is stored. These systems operate automatically from heat sensors or fusible links and may be manually activated by pull stations. They are inspected bi-annually by an outside service contractor.
  • automatic sprinkler systems are in place in a very few buildings. Many more buildings have hoses and standpipes. These systems are tested and maintained by Plant Services.
  • fire drills are conducted to familiarize building occupants with emergency evacuation procedures. An alarm activation should be considered a university order for evacuation; all occupants must evacuate and should not re-enter until advised to do so by the person in charge. Fire drills are conducted by DOES and assisted by Security, bi-annually in residence halls and annually for all other buildings (see related article on page 3).

The policies and programs outlined above are designed to reduce and control fire hazards. No "program" or "system" is perfect, however, and the possibility of a fire occurring is very real, as we have witnessed over the past few years. Recognizing and eliminating potential fire hazards are the best ways to reduce the chances of a fire occurring; knowing how to respond if a fire does occur is vital to getting through it safely.

Chemical "Unknowns": How Fire Can Erupt

It is vital that researchers label working samples of chemicals in the lab with not only their name but with the chemical compounds as well. Two years ago, an unknown (unlabeled) chemical, left on a storage shelf after the previous researcher, dried out and began a reaction that forced the evacuation of the entire Medical School and could have easily exploded or burst into flames.

Unfortunately, old chemicals left on lab storage shelves "for the next guy" are one of the biggest and most expensive problems new lab personnel can have. If they are unknowns, they must be disposed of as hazardous waste, since it costs more for analysis than for disposal. Instead of incurring the cost, researchers usually let these unknowns sit on their shelves, becoming potentially hazardous, reactive or flammable.

The answer to this problem with seemingly no good solution is simple: when you put your name on working samples, add the chemical constituents as well. Put them on even if the solutions are innocuous, such as water or salt solutions, because even though you know they are not dangerous, you also might forget to toss it out when you are done; you might even forget yourself what's in it.

Also, be sure all labels are securely attached; the most detailed description of chemical breakdown on a label does no good if the label falls off.

Chemical inventories from all researchers are now required so that situations like this involving unknowns can be discovered and taken care of as soon as possible. If you have not done a chemical inventory recently, DOES urges you to go through your stock now, looking for any bottles with damaged or missing labels. The potential for fire or explosion is very real when unknowns are on hand, and though reactions may seem unlikely, we have witnessed first-hand the destruction from just such a chemical.

Using Electricity Safely

Electricity is something so taken for granted that we stop wondering whether a piece of equipment is safe very soon after we turn it on. If it works, it must be OK. But there are many things to consider when using electricity in the laboratory since interruptions of electricity often harm or ruin experiments. Even more serious is the possibility of fire, which can occur when electrical connections go awry. Therefore, periodic checking of your electrical equipment, as well as keeping in mind the following suggestions, can help maintain the highest levels of laboratory safety.

  1. All electrical equipment or apparatus used in the lab must be suitable for use and for its location. Open frame motors, exposed heating elements, or anything else that can generate a spark should not be used with or near any procedures using flammable/combustible liquids.
  2. The equipment must be in good condition. Power cords, connecting cables, and wiring should not have any worn or frayed insulation or bare wires. Power plugs and sockets must be securely fastened to the wiring and there should be no splices.
  3. Safety features, fuses, thermostats, grounds, overheat sensing/cutoff devices tipover switches, etc. must be in place and working. Never try to bypass using these or other safety features.
  4. Multitap adapters and extension cords shouldn't be used since they may overload circuits. Don't use more electrical equipment than the room's/building's electrical system can safely handle.
  5. "Custom made" equipment must conform to good electrical safety practices including adequate proper wiring, overcurrent and overheat protection, grounding, no open wires or terminals, etc.
  6. Do not handle any electrical connections with wet hands or when standing in or near water.
  7. Do not try to repair equipment yourself unless you are qualified and fully understand the repairs required. All repairs should be done by qualified personnel.
  8. In case of fire on or near any electrical equipment, turn it off if it can be done safely.

If in doubt, don't use it. Call DOES (x2907) or Plant Services (x2580) if you have any questions regarding the safety of electrical equipment and/or wiring.