Hazards of Circulating Air Contaminated by Unsealed Radioisotopes in Clean Benches and Safety Cabinets

Most of the antineoplastic drugs used in the treatment of tumors are carcinogenic to humans. Hospital nurses are often subject to possible occupational carcinogen exposure. Exposure may occur during handling and administration of infusion solutions containing cytostatics. A genotoxicological monitoring system to detect genotoxic changes was developed in our laboratory, helping to improve working conditions and subserving primary prevention. Multiple-endpoint follow-up genotoxicological monitoring was performed in peripheral blood lymphocytes (PBLs) among 4 groups of 95 nurses (152 investigations) occupationally exposed to cytostatics. The results were compared to those of historical and industrial controls. The genotoxicological endpoints were the determination of the frequency of sister chromatid exchanges (SCEs) and the cells with high-frequency SCEs (HFC), the frequency of structural and numerical chromosome aberrations, and the measurement of ultraviolet-light-induced unscheduled DNA-repair synthesis (UDS). In Hospital 1, where nurses worked without a safety cabinet, the percentage of cells with chromosome aberrations (AC) was significantly higher than that of the controls. In Hospital 2, where nurses used inadequate safety cabinets (with horizontal airflow), significantly elevated levels of AC, SCE, HFC, and UDS were detected. During follow-up, in Hospital 2 at the time of the second investigation AC was still significantly higher, although safety conditions had been improved. The results indicate the presence of genotoxic damage in hospital nurses working with no or inadequate safety equipment. In Hospitals 3 and 4 where nurses using biological safety cabinets, the results were lower than those in the previous two groups. In Hospital 3 in the first year of the study AC was as at the level of industrial controls. During follow-up in the course of the repeated investigations a fluctuation in AC above the control level and an increase in HFC in yr 4 and 6 of the study were observed. In this group, the fluctuation in AC and HFC during the study points to the possibility of genotoxic exposure with cytostatics despite of the use of suitable safety cabinets, drawing attention to other possible routes of exposure. In Hospital 4, both AC and HFC were elevated. These data corroborate the need to maintain safety measures to avoid exposure, and the necessity of intervention in the case of exposure when using and handling hazardous carcinogenic agents. The results also indicate a certain expression time for genotoxic changes, which can lead to late somatic mutations as well as to a possible higher risk of cancer.

Periodically testing the performance of any biological safety cabinet or other sterilization chambers is mandatory; hence, the importance of evaluating the effects of error factors on this performance arises. Until now, despite the necessity of disinfection against many microorganisms, particularly protection against the current pandemic, international standards for the manufacturing and evaluation of safety cabinets did not recommend testing the ultraviolet C performance inside these safety cabinets. The main aim of this paper is to use the sensitivity coefficient as one of the essential terms in uncertainty evaluation, to study the effect of different distances and tilt angles on the irradiance and, hence, the uniformity inside the cabinet or chamber. It was found that the homogeneity of the distribution of irradiance levels along the irradiated area was significantly affected by the distance and angle. The results obtained utilizing the sensitivity coefficient indicated that a simple increase in distance will result in a considerable loss in the irradiance value reaching around 30%. Every 5° increment in the tilt angle causes a decrement in the irradiance value by about 14% compared to the original value (0°); hence, the uniformity decreased significantly by around 45%. These effects may reflect on the sterilization performance of the cabinet as an essential process. At the end of this paper, due to the importance of considering these measurements and the effect of the two parameters on irradiance and, hence, the uniformity, the author recommends that these measurements be added to international standards for safety cabinets manufacturing and evaluation. The recommendation may help to focus more on evaluating the ultraviolet C homogeneity performance inside biosafety cabinets.

The biological safety cabinet is the one piece of laboratory and pharmacy equipment that provides protection for personnel, the product, and the environment. Through the history of laboratory-acquired infections from the earliest published case to the emergence of hepatitis B and AIDS, the need for health care worker protection is described. A brief description with design, construction, function, and production capabilities is provided for class I and class III safety cabinets. The development of the high-efficiency particulate air filter provided the impetus for clean room technology, from which evolved the class II laminar flow biological safety cabinet. The clean room concept was advanced when the horizontal airflow clean bench was manufactured; it became popular in pharmacies for preparing intravenous solutions because the product was protected. However, as with infectious microorganisms and laboratory workers, individual sensitization to antibiotics and the advent of hazardous antineoplastic agents changed the thinking of pharmacists and nurses, and they began to use the class II safety cabinet to prevent adverse personnel reactions to the drugs. How the class II safety cabinet became the mainstay in laboratories and pharmacies is described, and insight is provided into the formulation of National Sanitation Foundation standard number 49 and its revisions. The working operations of a class II cabinet are described, as are the variations of the four types with regard to design, function, air velocity profiles, and the use of toxins. The main certification procedures are explained, with examples of improper or incorrect certifications. The required levels of containment for microorganisms are given. Instructions for decontaminating the class II biological safety cabinet of infectious agents are provided; unfortunately, there is no method for decontaminating the cabinet of antineoplastic agents.

During the outbreak and future public health security, the safety cabinet industry gradually took to the forward momentum of development, the safe cabinet from the normal delivery tank through the software design to implement the "sell" face-to-face in universities. According to the survey, most students lose some take-out. Safety cabinets not only solve the problem of the safety delivery courier, also pay attention to public health in this era of successful implementation without personnel contact. Through the software design, the dining room also unified blocks with the school management, and students can order food through the canteen they want to go to, which provides a large number of different choices for students so that they won't get tired of eating in the same area. With the popularization of 5G in the future, the combination of "unmanned delivery mode" can reduce more risks in terms of public health and make people's lives more convenient.

The high incidence of tuberculosis among necropsy workers is well known and several problems related to their working conditions have been pointed out. We investigated the possibility of infection with tubercle bacilli under necropsy working conditions using guinea pigs housed in a necropsy room in which about 2,000 necropsies per year were carried out. Tuberculosis infection developed in one out of five guinea pigs. In addition, we exposed five guinea pigs to tubercle bacilli and sacrificed them in a safety cabinet. The lungs, livers, and spleens were resected, flattened, and sliced finely on a cutting board. Detection of tubercle bacilli from filtered air and the surfaces of the room was attempted, however, no bacilli were cultured. The resected tuberculous lungs were intra-tracheally treated with formalin or physiological saline and the viability of the bacilli in the lung was assessed. Bacilli survived up to two hours after physiological saline injection but no viable organisms were detected after 15 minutes of formalin treatment. These findings indicate that the necropsy room workers were exposed to tuberculosis infection. As a preventive control measure, we recommend to treat tuberculous organs in the safety cabinet and to slice lungs after formalin treatment.

Safety cabinets—the British Standard revised

소방서, 스쿠버 등 공기호흡기 용기 충전시설의 고압가스안전관리법에 따른 허가 또는 신고를 하지 않고 운영하고 있으며, 시설개선 및 공기호흡기 충전중 사고발생에 따른 안전관리가 필요하다. 정부에서는 불법운영 해소를 위해 노력하고 있으며, 고압으로 인한 위험으로부터 안전거리와 방호벽 설치와 동등이상의 안전성을 확보하기 위한 방법으로 안전충전함을 설치하여 운용하는 방법을 대안으로 제시하였다. 방호벽 설치기준을 갈음할 수 있는 안전충전함은 용기파열 시 순간 과압이 원만하게 분산될 수 있는 내부구조를 가져야 하며, 파편이 분산하는 것을 최소화 하고 모든 파편의 외부 비산을 방지하고, 외부로 방출되는 과압이 작업자가 위치하지 않은 곳(상부 및 하부)으로 분출되도록 하여 방호벽의 성능을 갖추도록 하여야 한다. 본 연구에서는 압축공기의 물리적 폭발에 따른 피해 영향을 계산하고, 실제 충전함 시제품을 제작하여 시험용 용기를 가스로 파열시키는 파열시험으로 안전충전함의 외함변화를 관찰 한 결과, 공기 배출구조설계 등을 통하여 안전충전함 내부의 과압을 해소할 수 있음을 확인 하였다. A fire station and scuba have operated filling facilities for respiratory high-pressure cylinder without getting authority or reporting according to High-Pressure Gas Safety Control Act. They need facility improvement and special management to make provision for the time of accident during filling process. The Government have strived to correct illegal operations and suggested an alternative, establishing and operating the safety cabinet. It insures a safety being distance from danger caused by overpressure and a safety provoked by the protective wall equals or superiors. The safety cabinet is required to have an internal structure that smoothly distribute overpressure at the time of rupture. Plus, it needs to minimize fragments. It is also equipped with the performance of protective wall that makes overpressure to outside vent on the place where there is no person (top or bottom). This study calculated the consequence of physical explosion damage and built a prototype of safety cabinet. In addition, through the gas burst test, it derives for the ways to mitigate the physical explosion damage.

Most antineoplastic agents used in chemotherapy are cytotoxic and could damage the health of medical staff when they are exposed to them. To counter this risk, a safety cabinet is commonly used. Since such cabinets have been reported to be lacking, the PhaSeal® system (PS-s, a sealed-type safety device) was developed for use with the safety cabinet, and has been reported to be effective in studies done in Europe and the US. We tested the PS-s at a medical institution in Japan with regard to suitability and easy of operation. In the testing, the PS-s was compared with the conventional system (C-s) as regards preparation time using ten pharmacists and ten nurses as subjects. Afterwards, a questionnaire survey on the test results was conducted.The total preparation time required for C-s was 42.6±11.15 seconds and that for PS-s was significantly longer at 63.3±14.99 seconds (p<0.01). The time required for aspiration of drug from the vial was 27.2±9.08 seconds for C-s and 17.7±5.53 seconds for PS-s, which was significantly shorter (p<0.01). The questionnaire survey results indicated that PS-s was much safer to use for medical professionals but their opinions were divided as to whether it was easier to operate or not. We concluded that PS-s would be useful in the preparation of cytotoxic anticancer agents if medical staff could become more familiar with its operating procedure.

A method for determining operator protection factors in Class I and Class II microbiological safety cabinets and for evaluating product protection factors in Class II cabinets, is described. The technique employs an aerosol of potassium iodide droplets produced by a spinning disc generator together with special centripetal air samplers detecting any aerosol escape. The method meets the requirements of British Standard (BS) 5726 and is an alternative to the microbiological technique.The method has been used to evaluate the performance of a number of safety cabinets in relation to the requirements of BS 5726.Working procedures and unsuitable environments have been shown to prejudice the containment performance of open‐fronted cabinets by several orders of magnitude.The relationship between inflow air velocity and protection factors in Class I safety cabinets has confirmed the optimum requirements defined in the British Standard.

In many biological research laboratories, besides the paramount need to protect the workers from infection, there is also an important requirement to maintain clean or sterile conditions for the work being handled. It should be noted that potentially hazardous biological material used in microbiological safety cabinets generally can be rendered safe by decontamination methods such as fumigation with formaldehyde gas. Filter testing methods, although playing a vital part in the safety performance of many containment systems are outside the scope of this chapter. It is now fully described in BS 5726 for testing microbiological safety cabinets; in addition, it is widely used to measure the operator protection of a whole range of other containment systems including laboratory fume cupboards. National Standards for safety cabinets and microbiological safety cabinets specify methods for assessing operator protection and these techniques can be used for risk assessment as is required by many regulatory authorities in many countries.

This report describes a survey of microbiology laboratories (n = 467) serving Brazilian hospitals with ≥10 intensive care beds and/or involved in the government health care adverse event reporting system. Coordinators were interviewed and laboratories classified as follows: Level 0 (no minimal functioning conditions-85.4% of laboratories); Level 1 (minimal functioning conditions but inadequate execution of basic routine-6.7%); Level 2 (minimal functioning conditions and adequate execution of basic routine but no adequate procedures for quality control-5.8%); Level 3 (minimal functioning conditions, adequate execution of basic routine, and adequate procedures for quality control, but no direct communication with the infection control department-0.9%); Level 4 (minimal functioning conditions, adequate execution of basic routine, adequate procedures for quality control, and direct communication with infection control, but no available advanced resources-none); and Level 5 (minimal functioning conditions, adequate execution of basic routine, adequate procedures for quality control, direct communication with infection control, and available advanced resources-0.9%). Twelve laboratories did not perform Ziehl-Neelsen staining; 271 did not have safety cabinets; and >30% without safety cabinets had automated systems. Low quality was associated with serving hospitals not participating in government adverse-event program; private hospitals; nonteaching hospitals; and those outside state capitals. Results may reflect what occurs in many other countries where defining priorities is important due to limited resources.

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