Radiation Safety at Tufts Helpful Hints for Radioisotope Users

Personal Protective Equipment Be sure your lab coat is long enough; close/button it completely whenever in the lab; do not roll up sleeves exposing bare skin. Lab coats gathered or with elastic at the wrist are preferred to ones that hang away from the wrist. Double gloving is recommended to prevent skin contamination if one glove has a hole or tears. Avoid open-toed shoes, shorts and skirts when working with radioactive materials.

Eye Protection and handling RAM Wear safety goggles anytime there is a splash hazard. This includes when pouring liquid radioactive waste, handling concentrated solutions, and vortexing samples. Know where the nearest eyewash is located and how to use it.

Using stock vials of radioactive material [RAM] Thaw completely before attempting to take an aliquot from a stock vial. Incomplete thawing may result in a frozen portion of concentrated radioisotope escaping from the vial. Such ice can slide across counters and floors leaving large areas contaminated.

Tube selection in the lab When using radioactive material, screw top tubes are better than flip top tubes. The more secure the closure of the tube, the less likely it is to pop open, ex. during centrifugation or when heating the contents. Securely closed tubes prevent spills.

Using incubators with RAM Whenever possible, place flasks containing RAM cultures or solutions in secondary containers to prevent spills and contamination of the incubator. Use the lowest shelf available in the incubator so that you are not reaching for containers that are over your head. Straining to reach a container can lead to a spill.

Incubators continued Open dishes or flasks containing radioisotope, especially some chemical forms of S-35 [ex. Methionine], can result in the water within the incubator becoming contaminated. Be careful opening the inner incubator door to avoid contact with condensation droplets. Place absorbent paper on the counter in front of the incubator to catch any contamination. Place the incubator as far back on the bench top as feasible. Be sure to survey in front of incubators to check for radioactive contamination.

Spin Columns and RAM Used spin columns can pose a radiation contamination hazard. When the powder matrix in the column dries, radioactively contaminated powder can be spread around the lab. Place all used spin columns in conical tubes or plastic bags, and then into the radioactive waste container to avoid contamination of the lab.

Ice buckets Ice buckets used to cool tubes of radioactive material frequently become contaminated. Dispose of the used ice in a sink designated for radioactive material disposal. Rinse the sink well to help the ice melt and to decontaminate the sink before anyone else uses it.

Centrifuge Balance the centrifuge well to avoid breakage and Contamination of the inside of the centrifuge. Wipe off tubes before centrifugation to avoid contaminating the inside of the centrifuge. Close tubes tightly, preferably using screw top tubes. Let the centrifuge stop completely before opening, esp. bench top models. Broken tubes in a moving centrifuge can spray radioactive material on personnel and the lab.

Shakers Place plastic-backed absorbent on a shaker to catch any spills. This allows one to dispose of the contaminated absorbent in the RA waste container, and can save hours of cleaning. This is especially important with shared equipment = no down time.

Gel Handling Wear gloves and lab coat when handling gels. Be aware of dose rate from P-32 containing gels. Dispose of as a solid or dry RA waste. Ensure gel does not run through processor with the autoradiography X-ray film.

Electrophoresis &Autoradiography Prevent fires with proper use of gel electrophoresis equipment. Ensure proper voltage and avoid running gels overnight when labs are not attended. Equipment should be labeled as containing RAM. Be sure autoradiography cassette is labeled as containing RAM so all potential handlers/users are aware. Cassettes must also be kept secure from loss or theft per MA RCP regulations.

Avoid contamination of a meter If your geiger counter probe is contaminated, you will not be able to perform safety surveys. Do NOT cover the probe with Parafilm, as this reduces detector efficiency, esp. with C-14 and S-35. Turn/hold the probe sideways to survey your hands so any droplets do not fall onto the pancake probe. Do not touch the probe to surfaces to survey – use ½ inch detector to surface distance.

Post Experimental Surveys Performing radiation contamination surveys periodically during RAM use and immediately after each use of RAM is the “heart” of a good radiation safety program. Find any contamination early, before it is spread around the lab or contaminates others. Frequent surveys are ALARA and save work in the long run.

Change of clothing It is recommended that those who work directly with radioisotopes keep a change of clothing for emergencies. Spills can happen. If one’s clothing is splashed with radioactive materials [or other chemicals] having a clean set of clothing readily available is very helpful. This can be your own clothing or a set of scrubs, which you can keep in a locker or desk drawer in case it is needed.