Aim. occur. Hyt. VoL 20, pp. 3OJ-311. Pergomon Pros 1977. Printed In Great Britain
RADIOLOGICAL SAFETY BY DESIGN—I A U.S. VIEWPOINT
Abstract—Under the Radiation Control for Health and Safety Act enacted by the U.S. Congress in 1968, the Food and Drug Administration's Bureau of Radiological Health may prescribe performance standards for products that emit radiation. This paper describes the development of these standards and outlines the administrative procedures by which they are enforced.
are many Federal and State laws in the United States that apply to manufacturers and users of equipment that produce ionizing radiation. One of the Federal laws that applies to manufacturers of these products and therefore has a direct relationship to the provision of radiological safety by design, is the Radiation Control for Health and Safety Act of 1968 (U.S.A. Congress, 1968). This paper describes the basis of this law and how performance standards, developed in the interest of public health and implemented through an active enforcement programme, can have a significant impact upon the safe use of a product without limiting its usefuless. The provisions of the Radiation Control for Health and Safety Act apply to all electronic products manufactured, assembled, or imported into the United States. The term "electronic product" is defined as any manufactured or assembled product capable of emitting electronic product radiation, or any manufactured article intended for use as a component or accessory of such a device which can affect the emitted radiation. Radiation as defined by the Act includes both ionizing and nonionizing electromagnetic and particulate radiation, as well as sonic, infrasonic, and ultrasonic waves. Types of products that fall within the definitions include: X-ray machines, television receivers, accelerators, diathermy units, laser products, microwave ovens, and ultrasonic cleaners. When the U.S.A. Congress was considering the need for legislative action, testimony before Congressional committees (U.S.A. CONGRESS HOUSE COMMITTEE, 1967; U.S.A. CONGRESS SENATE COMMITTEE, 1967) cited a number of electronic products that might present a hazard either from radiation produced as an unintended result of their use, as a consequence of a mechanical or electrical defect, or from a lack of training or experience of service personnel. In order to deal with these hazards, a legislative mechanism was provided which allowed the establishment of certain restraints upon the design and manufacture of certain categories of equipment. The responsibility for the day-to-day implementation and enforcement of the provisions of the Act has been delegated to the Food and Drug Administration's Bureau of Radiological Health which also has established and is maintaining liaison with interested persons, both inside and outside of government, and is supporting research and training in methods of eliminating unnecessary exposure to radiation. THERE
305
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W A L T E R E. G U N D A K E R
Bureau of Radiological Health, Food and Drug Administration, Roclcvilk, Maryland, U.S.A.
306
W. E. GUNDAKER
PRINCIPAL REQUIREMENTS
STANDARDS DEVELOPMENT PROCEDURE
The procedure for developing a standard has been prescribed in some detail by the Act and is given a high priority in the implementation of the law by the Bureau of Radiological Health. It is during this time that all parties concerned—manufacturers, purchasers, users and public health authorities—are invited to participate in a procedure for formulating the requirements that eventually become mandatory. The Bureau determines the need for a performance standard from many factors, including the results of biological effects investigations, products studies, and the reports of potential or demonstrated hazards associated with a type of radiation, or a specific product. Considerations are given to the last available scientific and medical data; to the standards currently recommended by other Federal agencies or public or private groups having an expertise in the particular field of electronic product radiation ; to the adaptability of standards to the need for uniformity and reliability of testing and measuring procedures; and in the case of components or accessories, to the performance of this article when it is assembled in a completed product. In developing the information necessary to prepare a standard, laboratory testing is generally carried out to identify the engineering parameters inherent in the design. This laboratory testing is also necessary to develop the instrumentation and compliance test procedures that enable a manufacturer and the Bureau to determine whether the standard is being complied with. The essential concern is always the protection of the public health, and the Bureau is limited in its efforts to achieve such protection only by considerations of reasonable and technical feasibility. The provisions of a performance standard may include a definition of the maximum level of radiation emission permissible from an electronic product and a procedure for the testing of the product and the measurement of the emitted radiation. It may also require the attachment of warning signs and labels, and the providing of instructions for the installation, operation, and use of the product. The requirements must address the performance of a product and not its design. This is most easily done when establishing the levels of radiation emission permitted from a product, such as a limit of 0.5 mR/h at 5 cm from the surface of cabinet X-ray system. It becomes much more difficult when describing warning signs and labels, but alternative working is generally permitted if there is a need to vary from the wording specified.
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The Act requires the Food and Drug Administration to prescribe performance standards for controlling radiation emission from specific products when it is deemed that such standards are necessary for the protection of the public health and safety. Once a standard takes effect, a manufacturer of that product can introduce into commerce only products that comply with the standard. If it is found that the products do not comply (or contain a defect which is described in a later section of this paper), the manufacturer must notify the purchasers of the noncompliance and remedy the noncompliance by either repairing, replacing, or refunding the cost of the product Products imported into the United States must comply with the same requirements as those manufactured in the United States. The importer, however, is defined by the law as the manufacturer and thus the importer has the responsibility of ensuring that the products comply and of remedying items which fail to do so.
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307
Television receivers. The television standard applies to all home television receivers, closed circuit projection television receivers, and video monitors manufactured after 15 January 1970. The standard establishes a maximum X-ray exposure rate of 0.5 mR/h at 5 cm from the television receiver under specified test conditions. Demonstration tubes. After the discovery of an X-ray hazard in demonstration type cold-cathode gas discharge tubes, a performance standard setting a maximum exposure rate (10 mR/h at 30 cm) was established for these devices (U.S. Dept. of Health, Education and Welfare, 1976). The standard became applicable on 19 May 1970. Microwave ovens. This standard applies to microwave ovens manufactured for use in homes, restaurants, and food vending establishments. It is applicable to all ovens manufactured after 6 October 1971, and limits radiation leakage from an oven at 5 cm from the external surface to 1 mW/cm2 at the time of manufacture, and 5 mW/cm2 during the lifetime of the oven. The standard also places specific requirements on the door and safety interlocks. Diagnostic X-ray systems and their major components. The standard applies to major components, as well as complete systems, manufactured after 1 August 1974. Components covered by the standard are tube housing assemblies, X-ray controls, X-ray high voltage generators,fluoroscopicimaging assemblies, tables, cradles,filmchangers, cassette holders and beam limiting devices. The requirements address beam limitation, reproducibility and linearity, beam quality,fluoroscopeexposure limits and automatic exposure control devices. Cabinet X-ray systems. The provisions of this standard are applicable to cabinet X-ray systems manufactured after 10 April 1975, except that the standard applies to
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After it is determined that a standard should be developed, the Bureau outlines the basic concepts of the radiation safety goals that are to be achieved, their technical feasibility, and how they could be measured. Members of the affected industry and other interested parties are consulted and a revised proposal is then submitted for review by a technical advisory committee, created specifically by the Act and composed of five representatives of the affected industry, five representatives of governmental agencies, andfiverepresentatives of the public. When the recommendations of the Committee have received adequate consideration, a proposed regulation is published in the Federal Register, and generally 60 days are allowed for submission of public comments. The proposal is revised in response to these comments, and thefinalversion is published in the Federal Register as an official performance standard. To give industry adequate time to make the necessary adjustments, it generally takes effect between one and two years after final publication in the Federal Register. Furthermore, any person who feels that he will be adversely affected by a performance standard mayfilea petition for judicial review in the United States Circuit Court of Appeals at any time within 60 days after final publication of the standard. All of the Bureau's documentation relating to the background and development of each performance standard is available for inspection. At present, six performance standards have been promulgated for the following categories of products:
308
W. E. GUNDAKER
X-ray systems designed primarily for the inspection of baggage and packages (such as those used at airports and entrances to buildings) manufactured after 25 April 1974. The standard specifies an emission limit and requirements for controls, safety interlocks, and user service instructions.
ENFORCEMENT OF THE STANDARDS One of the procedures by which the Bureau determines whether a product is being made in compliance with a performance standard is through a close review of the quality control and testing programmes carried out by a manufacturer for this purpose; these are the basis upon which the manufacturer issues his certification of the product. The submission to the Bureau of a manufacturer's testing and quality control programme is required in the form of initial reports, reports of model changes and annual reports. The reports are reviewed in detail by Bureau personnel and the submitted information is checked against Bureau laboratory results and field information that may be available on the product. If the review shows that the programme is not in accord with good manufacturing practice and does not ensure that the products comply with the standard as authorized by the law, the programme may be disapproved. If it is disapproved, the manufacturer can no longer issue a certification that the product complies with all applicable performance standards. Rather than take the risk that he will have to modify or retest his products, most manufacturers have chosen to stop production until the inadequacies have been resolved. In conjunction with reviewing a report on the testing programme, a visit is made to the manufacturing facility to observe the programme in operation. These visits also include compliance testing of products through a random sample procedure, a review of the manufacturer's instrumentation and calibration programme, and an inspection of the records that a manufacturer is required to maintain. Even though the Radiation Control for Health and Safety Act permits enforced inspections when the Agency finds good cause that there may be a violation of the law, the in-plant inspection programme is conducted on a voluntary basis. The programme, conducted at manufacturing sites within the United States and overseas, has been valuable both in allowing Bureau personnel to understand the manufacturer's quality control procedures and in assisting the manufacturer to understand the requirements of the Bureau's performance standards. The physical size of many of the products subject to a performance standard lend themselves to laboratory compliance testing. These include television receivers, microwave ovens, some dental X-ray equipment and most laser products. The
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Laser products. All laser products manufactured after 2 August 1976 must comply with the emission limits, protective housing and safety interlock requirements of this standard. Each laser product must also be classified into one of four categories based upon the accessible emission limits for laser radiation. Work is also progressing towards the development of performance standards for ultrasonic therapy and surgery products, sunlamps and microwave diathermy equipment. Of course, periodical amendments are used to ensure that the standards remain consistent with technical innovations.
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309
DEFECT PROVISIONS
In addition to the principal authorities previously described, the Radiation Control for Health and Safety Act contains a mechanism for ensuring that all radiation safety defects in products are appropriately corrected. The defect provisions apply to all products manufactured after 18 October 1968, and cover all products for which there is no performance standard (a product subject to a performance standard may contain a radiation safety defect, but the standard will generally contain provisions for all items relating to radiation safety. Thus, failure to comply with a performance standard will constitute a noncompliance action, rather than being classified as a 'defect'). The precise definition of a defect may be found in the regulations published subsequent to the Act. In general, a product is considered to contain a defect if it fails to meet the manufacturer's radiation safety design specification, or it emits radiation which creates a risk of injury. As with the requirements of the law when there is a failure to comply with a performance standard, a manufacturer of a defective product must notify the purchasers of the defect and remedy the defect by either repairing, replacing, or refunding the cost of the product. Between October 1968 and February 1977, there have been 189 compliance actions involving defective and noncompliant products. Table 1 shows a breakdown of these compliance actions by product type, and includes the approximate number of products involved in each category. The data in this table, therefore, represent the number of products that manufacturers have had to remedy through purchaser notification and product correction. TABLE 1. BUREAU OF RADIOLOGICAL HEALTH COMPLIANCE ACTIONS OCTOBER 1968 THROUGH FEBRUARY 1977
Product
Estimated no. of units
Medical X-ray Dental X-ray Industrial and cabinet X-ray Television receivers Microwave ovens Miscellaneous
480 800 101600 150 900
Total
761350
15 500 12 100 400
Defect
Actions Noncompliance
Total
6
59 23 8 26 26 4
31 26 10
43
146
189
13 11 8 5 0
72 34
16
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products are obtained on a loan basis from the manufacturer, and thoroughly tested and evaluated against the requirements of the standard. If a failure to comply is found, the manufacturer is provided with the findings and given an opportunity to refute the data, submit a corrective action programme to remedy products already distributed, or apply for exemption from having to remedy the noncompliance. Other products, because of their large size, are best tested in a field-use location rather than a laboratory. Medical X-ray systems, for example, cannot be readily tested in the laboratory, and must be tested in a doctor's office, hospital, or other place of use. The FDA has its own trained specialists in the field to perform this testing and report the results to the Bureau of Radiological Health. The performance standards also apply for the useful life of a product, and testing under conditions of use provides the best method to measure this aspect of compliance.
310
W. E. GUNDAKER
COMMENTS ON EFFECTIVENESS OF STANDARDS
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Performance standards as promulgated under the Radiation Control for Health and Safety Act can, and do, have a significant effect upon controlling radiation emissions of products that are not intended to emit radiation, or do not need to emit radiation. For example, the performance standard for television receivers does not allow the leakage X-radiation to exceed a maximum of 0.5 mR/h at 5 cm from the surface of the receiver. The conditions under which this limit is measured became progressively more stringent in three successive stages. The most severe of these three is for all sets manufactured after 1 June 1971. The measurement must be made with all user and service controls adjusted to produce maximum X-ray emission, together with a component or circuit failure that maximizes emission. This performance standard, with test conditions that stress a receiver far above its normal operating range, has eliminated the earlier findings of radiation emission from television receivers. Any significant X-ray emission from television receivers is, of course completely unnecessary, and a performance standard establishing a limit, but not prescribing how a manufacturer must design his product to meet this limit, works extremely well for this type of product. Some products are designed to produce radiation as part of their intended function but the radiation can be completely enclosed to protect the user of the product and other members of the general public. Performance standards are also the primary radiation safety mechanism for this type of product. Examples are the microwave oven and the cabinet X-ray system. Even though the radiation is different, the basic principles of the solution to the problem of controlling the radiation are the same. The standards include a maximum emission limit of radiation from the product and detail requirements for interlocks to ensure the radiation source is turned off before any access to any interior space is permitted. The effectiveness of performance standards is diminished for products that are intended to produce radiation, and that utilize this radiation in such a way that it cannot be completely enclosed from either the user or the general public. The standard can limit the dimensions of the radiation beam or its direction, define the quality and quantity of the radiation, and provide instructions for the user on ways to minimize unnecessary exposure and obtain optimum utilization of the radiation. However, for this type product, the control of the hazards shifts from the product to the user. It is for this reason that, in addition to a performance standard for medical and dental X-ray equipment, the Bureau has an extensive effort aimed at reducing unnecessary exposure to the patient and operators through improving the practices of health practitioners and ancillary personnel who prescribe and administer the examinations. Programmes are also directed at identifying special problems in the use of X-radiation in medicine that result in unnecessary exposure. There are also products where a performance standard will only have a minimum impact on improving radiation safety. Portable industrial X-ray equipment is a product for which the control of the hazard is primarily the responsibility of the user. A standard could ensure adequate instructions and labelling but would have little benefit beyond that. In summary, standards and their enforcement will never solve all problems with all products. In administering the Act, every effort is made to achieve co-operation with electronic product manufacturers. The Bureau must rely very heavily upon the
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REFERENCES U.S.A. CONGRESS (1968) Radiation Control for Health and Safety Act of 1968. Public Law 90-602. 90th Congress, H.R. 10790,18 October 1968. U.S. Government Printing Office, Washington, D.C. (Copies of this Act and a compilation of the regulations published subsequent to it are available from Office of Information (HFX-25), FDA Bureau of Radiological Health, 5600 Fishers Lane, Rockville, Md 20857, U.S.A.). U.S.A. CONGRESS HOUSE COMMITTEE (1967) Hearings before the Subcommittee on Public Health and Welfare of the Committee on Interstate Commerce, House of Representatives. 90th Congress, first session, on H.R. 10790, 14 August 1967, ser. 90-11; second session, 1 February 1968, ser. 90-27. U.S. Government Printing Office, Washington, DC, U.S.A. U.S.A. CONGRESS SENATE COMMITTEE (1967) Hearings before the Committee on Commerce, United States Senate. 90th Congress, first session, on S.2O67, 28 August 1967; second session, on S.2067 and H.R. 10790, 6 May 1968, ser. 90-49. U.S. Government Printing Office, Washington, DC, U.S.A. U.S. DEPARTMENT OF HEALTH, EDUCATION AND WELFARE (1976) Regulations for the Administration
and Enforcement of The Radiation Control for Health and Safety Act of1968, p. 23. HEW Publication (FDA) 76-8035. FDA Bureau of Radiological Health, Md, U.S.A. DISCUSSION W. H. WALTON (Institute of Occupational Medicine): What is covered by 'cold-cathode discharge tubes'? Does it, for example, cover small neon pilot lights? MR GUNDAKER : The provisions of this performance standard apply to cold-cathode gas discharge tubes designed to demonstrate the effects of a flow of electrons or the production of X-radiation. Examples include fluorescence effect (also known as shadow effect or maltese cross tubes), magnetic effect and heat effect tubes. Neon lights are not covered by this standard, A. R. EYRES (Mobil Services Co. Ltd.): You mentioned that you have a programme for checking microwave ovens in use. To what extent do you find that ovens do not meet the standards ? MR GUNDAKER: Only a very small percentage of the microwave ovens tested in use fail to comply with the requirements of the performance standard. For example, in 1976 approximately 3000 ovens subject to the standard were tested and less than 2 % were found in noncompliance. Most of these noncompliant ovens were made by one manufacturer who is currently conducting a modification programme on all ovens sold.
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manufacturers themselves, to comply fully with the performance standard and the regulations concerning maintenance of records and submission of reports. To make a performance standard effective, however, it is necessary for the Bureau to conduct an enforcement programme. This is based upon the belief that if there is a need for a standard, there is a need for enforcement of it. This programme costs the Bureau both in terms of manpower and resources, and efforts are continually being made to streamline operations without a loss in capacity. The effectiveness of a radiation safety performance standard is derived from the clarity of the requirements in the law itself, and the regulations published subsequent to it. The Radiation Control for Health and Safety Act is very clear in the obligations it places on manufacturers who fail to comply with a standard. If the law had not been definitive, the Bureau would have been involved in many disputes over the need to remedy items of noncompliance. Finally, the standards, themselves, must be understandable, with a heavy emphasis on test conditions and measurement so that all parties have minimum room for individual interpretation that could result ultimately in difference of opinion.
RADIOLOGICAL SAFETY BY DESIGN—I A U.S. VIEWPOINT
Abstract—Under the Radiation Control for Health and Safety Act enacted by the U.S. Congress in 1968, the Food and Drug Administration's Bureau of Radiological Health may prescribe performance standards for products that emit radiation. This paper describes the development of these standards and outlines the administrative procedures by which they are enforced.
are many Federal and State laws in the United States that apply to manufacturers and users of equipment that produce ionizing radiation. One of the Federal laws that applies to manufacturers of these products and therefore has a direct relationship to the provision of radiological safety by design, is the Radiation Control for Health and Safety Act of 1968 (U.S.A. Congress, 1968). This paper describes the basis of this law and how performance standards, developed in the interest of public health and implemented through an active enforcement programme, can have a significant impact upon the safe use of a product without limiting its usefuless. The provisions of the Radiation Control for Health and Safety Act apply to all electronic products manufactured, assembled, or imported into the United States. The term "electronic product" is defined as any manufactured or assembled product capable of emitting electronic product radiation, or any manufactured article intended for use as a component or accessory of such a device which can affect the emitted radiation. Radiation as defined by the Act includes both ionizing and nonionizing electromagnetic and particulate radiation, as well as sonic, infrasonic, and ultrasonic waves. Types of products that fall within the definitions include: X-ray machines, television receivers, accelerators, diathermy units, laser products, microwave ovens, and ultrasonic cleaners. When the U.S.A. Congress was considering the need for legislative action, testimony before Congressional committees (U.S.A. CONGRESS HOUSE COMMITTEE, 1967; U.S.A. CONGRESS SENATE COMMITTEE, 1967) cited a number of electronic products that might present a hazard either from radiation produced as an unintended result of their use, as a consequence of a mechanical or electrical defect, or from a lack of training or experience of service personnel. In order to deal with these hazards, a legislative mechanism was provided which allowed the establishment of certain restraints upon the design and manufacture of certain categories of equipment. The responsibility for the day-to-day implementation and enforcement of the provisions of the Act has been delegated to the Food and Drug Administration's Bureau of Radiological Health which also has established and is maintaining liaison with interested persons, both inside and outside of government, and is supporting research and training in methods of eliminating unnecessary exposure to radiation. THERE
305
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W A L T E R E. G U N D A K E R
Bureau of Radiological Health, Food and Drug Administration, Roclcvilk, Maryland, U.S.A.
306
W. E. GUNDAKER
PRINCIPAL REQUIREMENTS
STANDARDS DEVELOPMENT PROCEDURE
The procedure for developing a standard has been prescribed in some detail by the Act and is given a high priority in the implementation of the law by the Bureau of Radiological Health. It is during this time that all parties concerned—manufacturers, purchasers, users and public health authorities—are invited to participate in a procedure for formulating the requirements that eventually become mandatory. The Bureau determines the need for a performance standard from many factors, including the results of biological effects investigations, products studies, and the reports of potential or demonstrated hazards associated with a type of radiation, or a specific product. Considerations are given to the last available scientific and medical data; to the standards currently recommended by other Federal agencies or public or private groups having an expertise in the particular field of electronic product radiation ; to the adaptability of standards to the need for uniformity and reliability of testing and measuring procedures; and in the case of components or accessories, to the performance of this article when it is assembled in a completed product. In developing the information necessary to prepare a standard, laboratory testing is generally carried out to identify the engineering parameters inherent in the design. This laboratory testing is also necessary to develop the instrumentation and compliance test procedures that enable a manufacturer and the Bureau to determine whether the standard is being complied with. The essential concern is always the protection of the public health, and the Bureau is limited in its efforts to achieve such protection only by considerations of reasonable and technical feasibility. The provisions of a performance standard may include a definition of the maximum level of radiation emission permissible from an electronic product and a procedure for the testing of the product and the measurement of the emitted radiation. It may also require the attachment of warning signs and labels, and the providing of instructions for the installation, operation, and use of the product. The requirements must address the performance of a product and not its design. This is most easily done when establishing the levels of radiation emission permitted from a product, such as a limit of 0.5 mR/h at 5 cm from the surface of cabinet X-ray system. It becomes much more difficult when describing warning signs and labels, but alternative working is generally permitted if there is a need to vary from the wording specified.
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The Act requires the Food and Drug Administration to prescribe performance standards for controlling radiation emission from specific products when it is deemed that such standards are necessary for the protection of the public health and safety. Once a standard takes effect, a manufacturer of that product can introduce into commerce only products that comply with the standard. If it is found that the products do not comply (or contain a defect which is described in a later section of this paper), the manufacturer must notify the purchasers of the noncompliance and remedy the noncompliance by either repairing, replacing, or refunding the cost of the product Products imported into the United States must comply with the same requirements as those manufactured in the United States. The importer, however, is defined by the law as the manufacturer and thus the importer has the responsibility of ensuring that the products comply and of remedying items which fail to do so.
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307
Television receivers. The television standard applies to all home television receivers, closed circuit projection television receivers, and video monitors manufactured after 15 January 1970. The standard establishes a maximum X-ray exposure rate of 0.5 mR/h at 5 cm from the television receiver under specified test conditions. Demonstration tubes. After the discovery of an X-ray hazard in demonstration type cold-cathode gas discharge tubes, a performance standard setting a maximum exposure rate (10 mR/h at 30 cm) was established for these devices (U.S. Dept. of Health, Education and Welfare, 1976). The standard became applicable on 19 May 1970. Microwave ovens. This standard applies to microwave ovens manufactured for use in homes, restaurants, and food vending establishments. It is applicable to all ovens manufactured after 6 October 1971, and limits radiation leakage from an oven at 5 cm from the external surface to 1 mW/cm2 at the time of manufacture, and 5 mW/cm2 during the lifetime of the oven. The standard also places specific requirements on the door and safety interlocks. Diagnostic X-ray systems and their major components. The standard applies to major components, as well as complete systems, manufactured after 1 August 1974. Components covered by the standard are tube housing assemblies, X-ray controls, X-ray high voltage generators,fluoroscopicimaging assemblies, tables, cradles,filmchangers, cassette holders and beam limiting devices. The requirements address beam limitation, reproducibility and linearity, beam quality,fluoroscopeexposure limits and automatic exposure control devices. Cabinet X-ray systems. The provisions of this standard are applicable to cabinet X-ray systems manufactured after 10 April 1975, except that the standard applies to
Downloaded from http://annhyg.oxfordjournals.org/ at The University of British Colombia Library on July 12, 2015
After it is determined that a standard should be developed, the Bureau outlines the basic concepts of the radiation safety goals that are to be achieved, their technical feasibility, and how they could be measured. Members of the affected industry and other interested parties are consulted and a revised proposal is then submitted for review by a technical advisory committee, created specifically by the Act and composed of five representatives of the affected industry, five representatives of governmental agencies, andfiverepresentatives of the public. When the recommendations of the Committee have received adequate consideration, a proposed regulation is published in the Federal Register, and generally 60 days are allowed for submission of public comments. The proposal is revised in response to these comments, and thefinalversion is published in the Federal Register as an official performance standard. To give industry adequate time to make the necessary adjustments, it generally takes effect between one and two years after final publication in the Federal Register. Furthermore, any person who feels that he will be adversely affected by a performance standard mayfilea petition for judicial review in the United States Circuit Court of Appeals at any time within 60 days after final publication of the standard. All of the Bureau's documentation relating to the background and development of each performance standard is available for inspection. At present, six performance standards have been promulgated for the following categories of products:
308
W. E. GUNDAKER
X-ray systems designed primarily for the inspection of baggage and packages (such as those used at airports and entrances to buildings) manufactured after 25 April 1974. The standard specifies an emission limit and requirements for controls, safety interlocks, and user service instructions.
ENFORCEMENT OF THE STANDARDS One of the procedures by which the Bureau determines whether a product is being made in compliance with a performance standard is through a close review of the quality control and testing programmes carried out by a manufacturer for this purpose; these are the basis upon which the manufacturer issues his certification of the product. The submission to the Bureau of a manufacturer's testing and quality control programme is required in the form of initial reports, reports of model changes and annual reports. The reports are reviewed in detail by Bureau personnel and the submitted information is checked against Bureau laboratory results and field information that may be available on the product. If the review shows that the programme is not in accord with good manufacturing practice and does not ensure that the products comply with the standard as authorized by the law, the programme may be disapproved. If it is disapproved, the manufacturer can no longer issue a certification that the product complies with all applicable performance standards. Rather than take the risk that he will have to modify or retest his products, most manufacturers have chosen to stop production until the inadequacies have been resolved. In conjunction with reviewing a report on the testing programme, a visit is made to the manufacturing facility to observe the programme in operation. These visits also include compliance testing of products through a random sample procedure, a review of the manufacturer's instrumentation and calibration programme, and an inspection of the records that a manufacturer is required to maintain. Even though the Radiation Control for Health and Safety Act permits enforced inspections when the Agency finds good cause that there may be a violation of the law, the in-plant inspection programme is conducted on a voluntary basis. The programme, conducted at manufacturing sites within the United States and overseas, has been valuable both in allowing Bureau personnel to understand the manufacturer's quality control procedures and in assisting the manufacturer to understand the requirements of the Bureau's performance standards. The physical size of many of the products subject to a performance standard lend themselves to laboratory compliance testing. These include television receivers, microwave ovens, some dental X-ray equipment and most laser products. The
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Laser products. All laser products manufactured after 2 August 1976 must comply with the emission limits, protective housing and safety interlock requirements of this standard. Each laser product must also be classified into one of four categories based upon the accessible emission limits for laser radiation. Work is also progressing towards the development of performance standards for ultrasonic therapy and surgery products, sunlamps and microwave diathermy equipment. Of course, periodical amendments are used to ensure that the standards remain consistent with technical innovations.
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309
DEFECT PROVISIONS
In addition to the principal authorities previously described, the Radiation Control for Health and Safety Act contains a mechanism for ensuring that all radiation safety defects in products are appropriately corrected. The defect provisions apply to all products manufactured after 18 October 1968, and cover all products for which there is no performance standard (a product subject to a performance standard may contain a radiation safety defect, but the standard will generally contain provisions for all items relating to radiation safety. Thus, failure to comply with a performance standard will constitute a noncompliance action, rather than being classified as a 'defect'). The precise definition of a defect may be found in the regulations published subsequent to the Act. In general, a product is considered to contain a defect if it fails to meet the manufacturer's radiation safety design specification, or it emits radiation which creates a risk of injury. As with the requirements of the law when there is a failure to comply with a performance standard, a manufacturer of a defective product must notify the purchasers of the defect and remedy the defect by either repairing, replacing, or refunding the cost of the product. Between October 1968 and February 1977, there have been 189 compliance actions involving defective and noncompliant products. Table 1 shows a breakdown of these compliance actions by product type, and includes the approximate number of products involved in each category. The data in this table, therefore, represent the number of products that manufacturers have had to remedy through purchaser notification and product correction. TABLE 1. BUREAU OF RADIOLOGICAL HEALTH COMPLIANCE ACTIONS OCTOBER 1968 THROUGH FEBRUARY 1977
Product
Estimated no. of units
Medical X-ray Dental X-ray Industrial and cabinet X-ray Television receivers Microwave ovens Miscellaneous
480 800 101600 150 900
Total
761350
15 500 12 100 400
Defect
Actions Noncompliance
Total
6
59 23 8 26 26 4
31 26 10
43
146
189
13 11 8 5 0
72 34
16
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products are obtained on a loan basis from the manufacturer, and thoroughly tested and evaluated against the requirements of the standard. If a failure to comply is found, the manufacturer is provided with the findings and given an opportunity to refute the data, submit a corrective action programme to remedy products already distributed, or apply for exemption from having to remedy the noncompliance. Other products, because of their large size, are best tested in a field-use location rather than a laboratory. Medical X-ray systems, for example, cannot be readily tested in the laboratory, and must be tested in a doctor's office, hospital, or other place of use. The FDA has its own trained specialists in the field to perform this testing and report the results to the Bureau of Radiological Health. The performance standards also apply for the useful life of a product, and testing under conditions of use provides the best method to measure this aspect of compliance.
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W. E. GUNDAKER
COMMENTS ON EFFECTIVENESS OF STANDARDS
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Performance standards as promulgated under the Radiation Control for Health and Safety Act can, and do, have a significant effect upon controlling radiation emissions of products that are not intended to emit radiation, or do not need to emit radiation. For example, the performance standard for television receivers does not allow the leakage X-radiation to exceed a maximum of 0.5 mR/h at 5 cm from the surface of the receiver. The conditions under which this limit is measured became progressively more stringent in three successive stages. The most severe of these three is for all sets manufactured after 1 June 1971. The measurement must be made with all user and service controls adjusted to produce maximum X-ray emission, together with a component or circuit failure that maximizes emission. This performance standard, with test conditions that stress a receiver far above its normal operating range, has eliminated the earlier findings of radiation emission from television receivers. Any significant X-ray emission from television receivers is, of course completely unnecessary, and a performance standard establishing a limit, but not prescribing how a manufacturer must design his product to meet this limit, works extremely well for this type of product. Some products are designed to produce radiation as part of their intended function but the radiation can be completely enclosed to protect the user of the product and other members of the general public. Performance standards are also the primary radiation safety mechanism for this type of product. Examples are the microwave oven and the cabinet X-ray system. Even though the radiation is different, the basic principles of the solution to the problem of controlling the radiation are the same. The standards include a maximum emission limit of radiation from the product and detail requirements for interlocks to ensure the radiation source is turned off before any access to any interior space is permitted. The effectiveness of performance standards is diminished for products that are intended to produce radiation, and that utilize this radiation in such a way that it cannot be completely enclosed from either the user or the general public. The standard can limit the dimensions of the radiation beam or its direction, define the quality and quantity of the radiation, and provide instructions for the user on ways to minimize unnecessary exposure and obtain optimum utilization of the radiation. However, for this type product, the control of the hazards shifts from the product to the user. It is for this reason that, in addition to a performance standard for medical and dental X-ray equipment, the Bureau has an extensive effort aimed at reducing unnecessary exposure to the patient and operators through improving the practices of health practitioners and ancillary personnel who prescribe and administer the examinations. Programmes are also directed at identifying special problems in the use of X-radiation in medicine that result in unnecessary exposure. There are also products where a performance standard will only have a minimum impact on improving radiation safety. Portable industrial X-ray equipment is a product for which the control of the hazard is primarily the responsibility of the user. A standard could ensure adequate instructions and labelling but would have little benefit beyond that. In summary, standards and their enforcement will never solve all problems with all products. In administering the Act, every effort is made to achieve co-operation with electronic product manufacturers. The Bureau must rely very heavily upon the
Radiological safety by design—I. A U.S. viewpoint
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REFERENCES U.S.A. CONGRESS (1968) Radiation Control for Health and Safety Act of 1968. Public Law 90-602. 90th Congress, H.R. 10790,18 October 1968. U.S. Government Printing Office, Washington, D.C. (Copies of this Act and a compilation of the regulations published subsequent to it are available from Office of Information (HFX-25), FDA Bureau of Radiological Health, 5600 Fishers Lane, Rockville, Md 20857, U.S.A.). U.S.A. CONGRESS HOUSE COMMITTEE (1967) Hearings before the Subcommittee on Public Health and Welfare of the Committee on Interstate Commerce, House of Representatives. 90th Congress, first session, on H.R. 10790, 14 August 1967, ser. 90-11; second session, 1 February 1968, ser. 90-27. U.S. Government Printing Office, Washington, DC, U.S.A. U.S.A. CONGRESS SENATE COMMITTEE (1967) Hearings before the Committee on Commerce, United States Senate. 90th Congress, first session, on S.2O67, 28 August 1967; second session, on S.2067 and H.R. 10790, 6 May 1968, ser. 90-49. U.S. Government Printing Office, Washington, DC, U.S.A. U.S. DEPARTMENT OF HEALTH, EDUCATION AND WELFARE (1976) Regulations for the Administration
and Enforcement of The Radiation Control for Health and Safety Act of1968, p. 23. HEW Publication (FDA) 76-8035. FDA Bureau of Radiological Health, Md, U.S.A. DISCUSSION W. H. WALTON (Institute of Occupational Medicine): What is covered by 'cold-cathode discharge tubes'? Does it, for example, cover small neon pilot lights? MR GUNDAKER : The provisions of this performance standard apply to cold-cathode gas discharge tubes designed to demonstrate the effects of a flow of electrons or the production of X-radiation. Examples include fluorescence effect (also known as shadow effect or maltese cross tubes), magnetic effect and heat effect tubes. Neon lights are not covered by this standard, A. R. EYRES (Mobil Services Co. Ltd.): You mentioned that you have a programme for checking microwave ovens in use. To what extent do you find that ovens do not meet the standards ? MR GUNDAKER: Only a very small percentage of the microwave ovens tested in use fail to comply with the requirements of the performance standard. For example, in 1976 approximately 3000 ovens subject to the standard were tested and less than 2 % were found in noncompliance. Most of these noncompliant ovens were made by one manufacturer who is currently conducting a modification programme on all ovens sold.
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manufacturers themselves, to comply fully with the performance standard and the regulations concerning maintenance of records and submission of reports. To make a performance standard effective, however, it is necessary for the Bureau to conduct an enforcement programme. This is based upon the belief that if there is a need for a standard, there is a need for enforcement of it. This programme costs the Bureau both in terms of manpower and resources, and efforts are continually being made to streamline operations without a loss in capacity. The effectiveness of a radiation safety performance standard is derived from the clarity of the requirements in the law itself, and the regulations published subsequent to it. The Radiation Control for Health and Safety Act is very clear in the obligations it places on manufacturers who fail to comply with a standard. If the law had not been definitive, the Bureau would have been involved in many disputes over the need to remedy items of noncompliance. Finally, the standards, themselves, must be understandable, with a heavy emphasis on test conditions and measurement so that all parties have minimum room for individual interpretation that could result ultimately in difference of opinion.
