PRINCIPLES AND TECHNIQUES OF RADIOISOTOPE APPLICATIONS 135 of dry air at standard temperature and pressure. The 0.3 R/wk. tolerance dose would cause no injury to personnel even if continued for a lifetime. A dentist exposes your jaw to more radiation during a 1/10 second x-ray exposure than you would get in several years of exposure to the 0.3 R/wk. exposure. The handling of radioactive materials which may get into the air as dust, gases, vapors or mists presents a much more difficult control problem. The degree of hazard from this source will depend on several factors. The behavior of the elements is important. Elements stored in the body are more hazardous than those that are readily excreted. This kind of radiation must be considered since some types are more damaging than others. The intensity or quantity of radiation being handled is a measure of the hazard. The half-life of a radioactive material is a measure of its active life. The longer the half-life, the more hazardous if stored in the body as a result of inhalation. In many cases where radioactive materials are used there may be waste products involved and, thus, a definite program for the disposal of these materials must be set up. One must be absolutely certain that in using radioactive materials one does not endanger either his employees or the general public. There is no reason why he should do this, since there has been considerable experience gMned already in handling radioactive iso- topes. Proper techniques and control measures hav.e been well described in the literature. Once a company has decided to undertake an experimental program using radioisotopes, it must consider where the work is to be done and what special facilities will be required. Thoughtful planning is essential and a well planned laboratory will facilitate the attainment of a successful program. If the proposed isotope program seeks a definite answer to one specific problem, the work may best be done by consultation with a firm equipped to handle radioisotope programs. If it is expected to last only a few months, it may be best to remodel already existing laboratory space. If' it is a program of sustained duration, it is probably best to make permanent installations and to utilize more durable and better grades of equipment. Since work with radioisotopes is generally at several levels of activity, it is best to separate the working space into areas, each area to contain not more than a predetermined level of radioactivity. Within each area it may be necessary, if work is being done with several radioisotopes, to sub- divide into sub-areas, one for each particular isotope. All working surfaces, floors and walls, should be constructed so that they may be readily decontaminated. Storage facilities for radioisotopes must be provided. The nature of these facilities depends upon which isotope is being used and in what quantity. The fume hood is probably the most important item in a radiochemical laboratory. The characteristics required for hoods designed especially

136 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS for working with radioisotopes are well established and properly designed hoods are commercially available. Adequate records are required. These include records of accountability of isotopes, health physics records such as film badge reports and dosimeter readings, physical examinations, etc. The keeping of these records should be the responsibility of the person appointed to be health safety officer. To get started in a radioisotope program, I would advise contacting one of the commercial firms for assistance. They can advise you on your par- ticular problem and steer you through the necessary routine. We at Tracerlab do not presume to be familiar with your problems in the cosmetic chemistry field. However, we may be able to assist you in applying this tool in the solution of your problem. I would like to spend a few minutes to discuss the types of statements I frequently hear. One may say, "I'd like to start a program, but I don't want to get mixed up in all that government red tape and hush-hush security." There is no security problem. Your employees do not have to be cleared by the FBI and you can keep your original development work company confidential if you like. The AEC will completely cooperate on this. As far as govern- ment red tape is concerned, there is very little. To use radioisotopes, you must satisfy the AEC that you can handle them safely and effectively. To do this, you sutlmit a written form answering a series of questions. That is the extent of the so-called red tape. Some may say, "It costs too much." True, it costs some to get started. The amount depends upon what type of program you have in mind. Any new equipment will require additional expense. But bear in mind that isotopes pay off in material saved, better product quality, and in produc- tion-less labor. Another question, "It is too dangerous. I'm afraid to start with it." There is no more danger than any of the other potential hazards you now have under control. Toxic chemicals and high voltage lines are dangerous but you manage to protect against them. Insurance companies do not think there is any special danger. They will continue at the same rates, insurance against fire and accidents. In closing, I would like to leave a few salient points in mind. A radioactive isotope is a chemical element that has been exposed to neutron bombardment and thus becomes radioactive. It gives off radia- tion. You can heat it, pour it if a liquid or saw it if a solid, but it is still the same material and is still radioactive. It cannot be distinguished from its stable counterpart by any chemical means. You can use it as a source of radiation to follow liquid flow, locate leaks, turn on a pump, gauging, radiography and in many other ways. As a tracer, minute amounts will tell you with great accuracy, when products are fully mixed, when changes occur (chemical and physical) and when your process is working properly.