Protective aprons

For the above scales, eye protection should be worn and work should be undertaken in a standard fume-cupboard behind a well-anchored polycarbonate screen. It is advisable to wear a protective apron and hand protection whether leather gauntlets or tongs should be used will be dictated by circumstances. Such measures are recommended but it should be ensured that they do not precipitate a hazard as a result of loss of tactile sensitivity (e.g. dropping a flask, overtightening clamps, exerting excessive pressure when assembling apparatus). The material of gloves needs consideration. (PVC but not rubber is suitable for tert-butyl peroxide.)... 

TAP Apron Toxicological Agent Protective Apron (Military). 

As a second example, consider a case in which the front of the body is irradiated by a nonuniform field of scattered radiation, the trunk is shielded by a protective apron on the front of the body, and the personal monitor value and tissue doses are as given in Table 1.3. The resulting values for He and E are 0.12 mSv and 0.05 mSv, respectively. In this case, the difference is caused primarily by the manner in which the remainder contribution is calculated (see Tables 1.1 and 1.2). Note also that a personal monitor located on the front at the neck outside and above the protective apron would have indicated a value of 1 mSv (see Table 1.3), which is a large overestimate of either He or . 

Irradiation of the front of the body by nonuniform field of scattered radiation, trunk shielded by protective apron on front of body. 

For many situations where protective aprons are worn, the exposure is primarily to the front of the individual. Under these circumstances, a personal monitor located under the apron on the trunk of the individual indicates the dose equivalent to the shielded trunk of the body, and unshielded parts of the body may receive higher exposure. A monitor located outside and above the apron indicates the dose equivalent to the unshielded parts of the body. 

Specific Approach When Protective Aprons Are Worn During Diagnostic and Interventional Medical Procedures Using Fluoroscopy... 

Clinical staff taking part in diagnostic and interventional procedures using fluoroscopy wear protective aprons to shield internal tissues and organs in the torso from scattered x rays. Use of the measurements from monitoring devices worn outside and above protective aprons as the record of or E for these individuals results in significant overestimates of their actual risk. 

The current situation is exemplified by a study of clinical staff exposures in cardiac angiography at the Montreal Heart Institute (Renaud, 1992). Extensive measurements of staff exposures were made using thermoluminescent dosimeters (TLDs) for 15,000 procedures in three cardiac catheterization laboratories over a 5 y period (1984 to 1988). The TLDs were located under the protective apron at the waist and at the collar outside and above the apron. Readings were made at three-month intervals, with a minimum reportable value of 0.2 mSv. Average values (in mSv per y) for various groups of staff, based on measurements with TLDs worn at the collar, are given in Table 3.3. 

NCRP recommends the u.se of protective aprons that are at least 0.5 mm lead equivalent (NCRP, 1989b). 

Table 3.3—Clinical staff exposures in cardiac angiography. Group averages (in mSv per y) based on measurements with TLDs worn on the collar outside and above protective aprons (Renaud, 1992). ...

When only one individual monitoring device is used and it is located at the neck outside the protective apron, the reported deep dose equivalent shall be the [//g] for external radiation or 2. When only one individual monitoring device is used and it is located at the neck outside the protective apron, and the reported dose exceeds 25 percent of the limit specified. .., the reported deep dose equivalent value multiplied by 0.3 shall be the [ITe] for external radiation or 3. When individual monitoring devices are worn, both under the protective apron at the waist and outside the protective apron at the neck, the [He] for external radiation shall be assigned the value of the sum of the deep dose equivalent reported for the individual monitoring device located at the waist under the protective apron multiplied by 1.5 and the deep dose equivalent reported for the individual monitoring device located at the neck outside the protective apron multiplied by 0.04. ... 

In this work, x-ray scatter radiation was produced at various x-ray tube potentials in the range of 60 to 120 kVp, with the x-ray tube in the over- or undertable position. Dose equivalents for clinical staff were determined using film badges placed at four or five locations, including the neck and waist, on a Rando phantom. Absorbed doses to tissues and organs, when a protective apron was not present, were determined using numerous TLDs in the phantom and auxiliary data from the literature when necessary. Absorbed doses to the tissues, when a protective apron was present, were estimated from the absorbed doses without an apron, as modified by transmission data for the appropriate x-ray tube potential and equivalent lead thickness. and E were computed for the noted range of x-ray tube... 

Tables 3.4 and 3.5 present the results for the neck and waist film badges when the indicated thicknesses of protective aprons are worn. Usually, the apron thickness is 0.5 mm lead equivalent, but auxiliary staff sometimes use thinner aprons or the back portion of a wraparound apron may be thinner, such as 0.3 mm lead equivalent.

Hw is the value of //p(10) for the personal monitor worn under a protective apron at the waist and Hk is the value of Hfi 10) for the personal monitor worn outside and above the apron at the neck. 

When a single personal monitor worn at the neck outside and above a protective apron is used, dividing/In, [i.e., the i/p(10) value for this personal monitor] by 5.6 to obtain a conservatively high estimate of He is recommended. Likewise, dividing/In by 21 to obtain a conservatively high estimate ofE is recommended. These modifications ofHti give appropriate credit for the protection afforded by the apron and do not overestimate the value of He by more than a factor of three or the value of E by more than a factor of 3.4. 

If an individual performs both radiographic procedures (i.e., procedures without use of a protective apron) and fluoroscopic procedures i.e., procedures with the use of a protective apron) during a given monitoring period, there may be no practical way to determine precisely the relative contribution each type of procedure made to the total /fp(lO) value recorded by a personal monitor. However, occupational exposure during radiographic procedures should be very low, since the worker is at a relatively large distance from the x-ray source and most often i.e., except for use of mobile x-ray systems) in a protective cubicle. 

If an individual s workload consists predominantly of fluoroscopic procedures, the recommendations given above with the protective apron are appropriate, when either a personal monitor is worn only at the neck outside and above the apron, or when personal monitors are worn both at the neck outside and above the apron and at the waist or chest under the apron. When the Hp(10) values recorded by the personal monitor worn at the waist or chest under the apron are consistently below the minimum detectable values, use of the recommendation for a personal monitor worn only at the neck outside and above the apron would be the more conservatively safe approach. 

If an individual s workload consists predominantly of radiographic procedures, where protective aprons are not worn, the recommendation given in Section 4.1 for use of Hp(lO) from one personal monitor as a surrogate for would be appropriate. For radiographic procedures, the irradiation conditions are adequately characterized by an anterior to posterior irradiation at effective energies of greater than 30 keV, with a personal monitor located on the front of the individual. 

ROSENSTEIN, M. and WEBSTER, E.W. (1994). Effective dose to personnel wearing protective aprons during fluoroscopy and interventional radiology, Health Phys. 67, 88-89. 

WEBSTER, E.W. (1989). EDE for exposure with protective aprons, Health Phys. 56, 568-569. 

Wear a protective apron. Use reasonable care in handling tools and materials Have proper ventilation. 

Staff should always wear personal protective clothing and equipment e.g. eye protection, face protection, aprons, gloves, protective boots, whenever handling fast pyrolysis liquid, in particular vdien handling large quantities ... 

KOH-sugar solution (10 grams of KOH -i- 5 grams of sugar -I- 20 mL deionized water). The liquid temperature for digestion should be approximately 80°C. This solution is extremely caustic and proper laboratory safety precautions such as eye protection, apron, and rubber gloves are recommended. 

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