wipes) and then counting the wipes by LSC analysis. A background (uncontaminated) wipe is counted as a comparison control. When using lower-energy beta emitters (H-3, C-14, S-35) surfaces should be checked with dry or damp pieces of filter paper or cotton swabs which are counted by liquid scintillation. Suggested areas to be examined: floor in front of work area, equipment (heaters, stirrers, tubing), and any items handled with work gloves during the experiment (faucet handles, drawer handles, pipetters). If extensive or high-level surface contamination (100 times background) is suspected, call EH&S. Record Keeping - Documentation is maintained on self-surveys. The count data should be tied to a survey map by means of numbers or letters, so that areas found to be contaminated can be identified.

########## CLEAN UP

All items involved in the experiment must be surveyed, discarded, or cleaned and properly stored. Rinse reusable contaminated glassware twice (dispose into the liquid radioactive waste) before cleaning. Do not allow potentially contaminated items to accumulate in the work area or the sink. Low-level surface contamination (bench or floor) may be cleaned in the following manner: rub alternately with a wet paper towel with cleaning solution, then a dry one. Start in least contaminated area and work to most contaminated. Discard the towels into the radioactive waste container after each application. If possible, one sink should be designated and labeled for radioisotope clean-up purposes and all glassware and liquids that might be slightly contaminated should be placed there.

########## WASTE DISPOSAL All contaminated or potentially contaminated material must be disposed of as radioactive waste.

Solid waste is placed in designated labeled containers. Place no liquid in the solid waste containers. Syringes and other sharp objects must be placed in appropriate infectious waste and sharps containers.

########## Liquid scintillation vials are disposed into designated containers. Animal and biological tissues are normally segregated from other wastes, labeled, and kept frozen until packaging.

If waste is transported out of the laboratory it must be properly contained. Liquid waste bottles must be labeled, bagged, and carried in secondary containment. Solid wastes must be double bagged. All wastes must be documented as to date, Principal Investigator, and activity present. Radioactive materials must be disposed CCR in accordance with the requirements of the CHORI radioactive material license and Title 17. Inappropriate disposal (such as to building trash) can result in significant expenditure to recover, regulatory action, potential criminal liability, and undesired publicity. Once materials such as radioactive shipping containers have been emptied and surveyed to assure that they are not contaminated, deface or remove the radioactive labeling and markings. The containers may then be disposed or recycled as appropriate.

########## METALLIC LEAD

DO NOT dispose of contaminated lead as dry waste or place it in common trash. Lead must be decontaminated or allowed to decay and disposed of as a hazardous material or recycled.

########## DISPOSAL OF LIQUID SCINTILLATION COUNTERS

Some liquid scintillation counters contain an internal radioactive source. This radioactive source must be