June/July 1995

Fire Alarms: Evacuating Effectively

Recently there have been instances of occupants refusing to evacuate when a fire alarm goes off. When a fire alarm sounds in a university building, whether for a scheduled drill or otherwise, all occupants are required to evacuate.

Security and fire department personnel arriving on the scene must concentrate on discerning the cause of the alarm and protecting life and property if necessary. All occupants should be out of the area so firefighting personnel can quickly and effectively locate and control any problems. If it is not a real emergency, then you will be allowed to return to your tasks as soon as possible.

We realize that evacuating during alarms, especially when they frequently go off, can frustrate ongoing work; however, the alternative-being trapped in a fire-is much worse. Please cooperate with this university mandate.

Fire emergency signs and exits are clearly marked on doors and hallways in all campus buildings. If a fire alarm goes off in your building, follow these signs to the nearest exit. Do not use the elevator. If you have further questions, contact Safety Services (x2907).

Drain Disposal: what can you pour down the drain?

The list of those substances that one can toss down the drain has become considerably shorter since the passage of the Resource Conservation and Recovery Act in 1976. Any wastes perceived as hazardous by the Environmental Protection Agency (EPA) can no longer be disposed of in this way. Below are some general guidelines concerning substances that cannot be drain-disposed.

  • Any solution containing more than 24% ethanol, methanol, isopropanol, or propanol.
  • Halogenated organics (solid or liquids); examples include: chlorobenzene, trichloroethylene, trichloroacetic acid, chloroform.
  • Non-halogenated organic liquids (aliphatic or aromatic); examples include: toluene, ethers, phenol. NOTE: The disposal costs for halogenated wastes are considerably higher than for non-halogenated wastes. PLEASE do not mix these wastes together; otherwise, the entire container will have to be disposed of as halogenated wastes.
  • Other miscellaneous solvents and mixtures; examples: vacuum pump oil, HPLC solvent mixtures containing organic solvents, and hazardous or nonbiodegradable scintillation fluid (non-radioactive)
  • Organic solids still in the bottle; examples: phenol, benzoic acid, naphthalene, most common organic chemicals
  • Concentrated inorganic acids and bases; examples: mineral acids, ammonia, sodium hydroxide
  • Inorganic chemicals; examples: copper chloride, mercury, mercuric chloride, lead salts (in solid and solutions forms)
  • Dioxins
  • Special chemicals (poisons, explosives, health hazards, highly reactive chemicals):
    1. Known carcinogens and mutagens
    2. Pesticides
    3. Osmium tetroxide
    4. Compressed gases (in non-returnable containers)
    5. Chromic Acid

How to Dispose of these Wastes Properly

Each laboratory should retain waste chemicals in a container labeled with the words "Hazardous Wastes," preferably plastic rather than glass. When the container is full, fill out a Hazardous Waste and Unwanted Chemical Disposal Listing form (sample in Appendix Ia of CWRU's Chemical Safety Manual), and send it to DOES at 216 Quail Building. One of our technicians will pick up the container as soon as possible.

Reducing the amount of waste created in the lab is also a way around having to dispose of it. We highly recommend that you use nonregulated substitutes in place of those substances listed above. If that is not possible, you can reduce the volume of hazardous waste by reducing the scale of an experiment or incorporating procedures in your experimental protocol which reduce the type and volume of hazardous waste produced.

Hazardous materials cannot be diluted with a material which is not a waste (water, for example) in order to bring them to concentration suitable for drain disposal. If you have questions, consult the Chemical Safety Manual or call Safety Services (x2907).

Moving? What To Do

Many researchers are moving from one part of the campus to another. While setting up the new lab to meet your tasks is important, it is also important that the old lab is left in a condition suitable for other uses. Below is a list of some of the items that must be completed in the lab you are moving out of both before and after you move.

NOTE: researchers moving off campus have additional requirements. If you are moving off campus, or if you would like further information, call DOES (x2906).

Before the Move

If your lab uses radioactive materials:

  • All radioactive waste must be disposed of.
  • The lab and all its equipment must be surveyed and the results recorded, since these results are checked by the Radiation Safety Office before the move.

For Safety Services to give its approval for the move:

  • All chemical waste must be disposed of.
  • All sharps or biohazards must be removed.
  • An updated chemical inventory (those chemicals that are going with the researcher) should be submitted.
  • A Right-To-Know session must be given to the contractor assisting in the move.

After the Move

Your old lab space must be decommissioned. If you used radioactive materials, the survey results will be confirmed by the RSOF.

When given permission from DOES, remove all signs and labels. Place new signs and labels in applicable places in your new lab.

Submit a new chemical inventory list, whether or not there are any changes.

Peroxide Formation in Ether

Ethyl ether is a potentially dangerous chemical because of its anesthetic and flammable properties. An additional danger comes from the peroxides that can form from residual amounts of ether left standing in closed containers. Explosions from peroxide formations are rare; however, knowledge of the hazardous properties of ethers and the special problems of peroxide formation in ether can contribute even more towards prevention.

General Hazardous Properties of Ether

  • Because of their high vapor pressures, ethers pose a particularly dangerous fire hazard and may ignite at only a 1% concentration laboratory air.
  • The explosive and flammable nature of ethers increases with heating.
  • Ethyl and isopropyl ethers are powerful narcotics which can cause unconsciousness and death upon acute exposure.
  • Ethers react violently with strong oxidizing agents such as sulfuric, nitric and perchloric acids and may explode upon mixing.

Peroxide Formation in Ether

  • Peroxides form in the air above contained sources of ether, and formation occurs easiest when large volumes of air come into contact with residual sources of ethyl ether. Thus, ether containers with only a few milliliters remaining are especially prone to peroxide formation.
  • Peroxide formation is a slow oxidative decomposition that generally takes several months in stabilized ethers; however, peroxides may form in freshly distilled and unstabilized ethers within less than two weeks.
  • Upon formation of peroxides, ethers can become friction-sensitive, shock sensitive, and heat sensitive, making detonation from any of these possible.
  • Isopropyl ether seems unusually susceptible to peroxidation.

Use, Storage and Disposal of Ethers

Use a fume hood for all transfers and reactions with ethers. Store ethers in a dark place since exposure to light contributes to peroxide formation.

Prompt disposal of small quantities of ether will minimize the hazardous formation of peroxides. Disposal should include an effort to note the date when the bottle was opened. All containers of ethers come with an expiration date; use or dispose of ethers before this time.

Finding the Right Meter for the Job

It is imperative when working with radiation that you monitor for contamination. However, there are several types of meters available for this. You must be certain that the meter you choose is designed to monitor the type of radiation with which you are working. You must also use these meters correctly so that they sufficiently protect you.

Types of Meters

Most of the meters used at CWRU laboratories are Ludlum meters and are one of three types:

  1. Model 44-9, or the pancake Geiger-Mueller probe: used for detecting beta particles such as P32, C14, and S35. It can also detect I125 emissions, but the efficiency is extremely low.
  2. Model 44-3, or the sodium iodide probe: used for detecting gamma radiation such as I125 emissions. The sodium iodide probe cannot detect other kinds of radiation well, so use this probe if you work with gamma emitters only and have no need to measure other isotopes.
  3. Model 44-21, or the sandwich probe: used for detecting all types of radiation isotopes, P32, C14, S35 and I125. It is specifically designed to pick up both beta and gamma emitters and is therefore the most universal in its detection.

How They Work

Again, finding the right meter is only the first step in efficiently monitoring radiation. The meter can only work efficiently if the cap if OFF. In fact, when you have your meter calibrated by the Radiation Safety Office, the efficiencies are calculated with a bare probe - no cap, or even parafilm. Why? Because beta radiation-particularly weak emitters such as C14 and S35-are partially or completely shielded by the plastic of the cap. They never reach the detector, and so they do not register on the meter. You could be passing up major contamination problems and never know it until someone meters properly.

If you use a combination of beta and gamma emitting isotopes in your lab, the best thing to do is always leave the cap OFF when using your meter. If you find contamination and you aren't certain which isotope it is, THEN put the cap on. If the reading is unaffected, it is probably a gamma emitter such as I125, though P32 will only be partially shielded. If you only use beta emitters, you should NEVER meter with the cap on. Just be careful to avoid contaminating the probe.

What and When to Monitor

Leave the meter on throughout the experiment as well as monitoring afterwards. Monitor your gloves several times throughout the experiment and don't forget to monitor your shoes, especially the shoe bottoms, before you leave the work area to avoid spreading radioactive contamination.

Tritium, remember, cannot be detected with any of these probes.

The above model numbers are specific to Ludlum probes. Different brands will use different model numbers, but the principles are the same. Call the Radiation Safety Office at x2906 if you have any questions concerning the above information. Monitoring radiation is effective only if done correctly.

Safety With Corrosive Materials

A corrosive material is defined as a chemical whose action will result in an immediate, acute erosive effect on bodily tissues as well as other substances. Though they are common in many laboratories, extreme care must be taken when working with these sorts of chemicals because they represent a hazard in several ways-through direct contact with the skin or eyes, through skin or eyes, through breathing or through ingestion.

Corrosive chemical liquids such as mineral acids, alkali solutions, and certain oxidizers, are especially dangerous to the skin and eyes because splashes so easily occur when working with them. Corrosive gases and vapors affect all parts of the body, though the eyes and respiratory tract are most susceptible to damage. Highly soluble gases such as ammonia or hydrogen chloride severely irritate the nose and throat, while less soluble materials like nitrogen dioxide phosgene, sulfur dioxide can penetrate further into the lungs.

Safe work practices in laboratory settings are explained in the CWRU Safety Manual, from which labs can create their Chemical Hygiene Plan (as required by OSHA). In addition to these general safety precautions, the following should be adhered to when working with corrosives.

Corrosive Chemical Liquids

  1. Wear proper face and eye protection. Accidental splashing occurs frequently, and eyes are extremely vulnerable to danger.
  2. Wear gloves and other chemically resistant protective clothing to prevent skin contact.
  3. Flash steam explosions can occur from mixing acids and bases, as large amounts of heat form at the liquids' interface. To prevent these steam explosions, always add acid and bases to water and not the other way around.
  4. Store acids and bases separately in the lab.
  5. Store liquid corrosives below eye level.
  6. Have adequate spill control ready in case an accident occurs.

Corrosive Gases and Vapors

  1. Use a fume hood when working with chemicals that may be harmful if inhaled, or wear other appropriate respiratory protection.
  2. Protect all skin surfaces from contact with corrosive gases or vapors.
  3. Remember that warning signs such as odor or eye, nose or respiratory tract irritation may be inadequate with some substances. They should not be relied upon as a warning of overexposure.

Awareness of the danger of corrosives materials is the first step in safe lab practice, so exercise the proper precautions when working with these materials. If you are unsure of a chemical's hazard, call the Department of Occupational and Environmental Safety (DOES) at x2907.

Waste Disposal Tags

Recently an article in the newsletter asked that waste amounts be listed in percentage concentration when filling out the waste disposal tag. However, the computer system we currently use requires that amounts be listed using the metric system. Therefore, we ask that you please convert percentages to liters or kilograms and write those amounts on the waste disposal tag. We apologize for the inconvenience this has caused some of you, and if you have further questions on the necessary procedure, please do not hesitate to call Safety Services (x2907).