Mark A. Puskar

INTERNAL WALL LOSSES OF PHARMACEUTICAL DUCTS DURING CLOSED-FACE, 37-MM POLYSTYRENE CASSETTE SAMPLING

A current practice for the determination of personal exposures to dusts involves the aspiration of known quantities of air through membrane filters held in 37-mm plastic cassettes. Samples are collected with the cassettes in the closed-face configuration. A major negative bias error has been identified with this sampling procedure for low-level pharmaceutical dusts. For the pharmaceuticals studied, on average, 62% of the active dust collected in each sample was found on the inside surface of the cassette top. Only 22% of the total active ingredient of the dust was found on the filters. The remaining 16% was found on the inside of the cassette bottoms; electrostatic attraction appears to be the reason that pharmaceutical dusts adhere to the inside surface of the cassette. Adherence to the inside surfaces of the polystyrene cassette occurs without regard to the type of material used to seal the two-piece cassette together. The use of shrink wrap versus plastic tape versus using no sealing material had no effect on where or how much of the active ingredient was found on the inside cassette surfaces. Because very little active ingredient was identified in backup cassettes, it is hypothesized that the active ingredient found on the inside of the bottom portion of the cassettes (past the filter and support pad) got there by falling off the filter during filter removal from the cassette prior to analysis. To eliminate both of these errors, an internal cassette extraction procedure was developed that (1) negates the error caused by static charging and (2) eliminates the need for opening the cassettes prior to analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

ANALYSIS OF ORGANIC VAPORS IN THE WORKPLACE BY REMOTE SENSING FOURIER TRANSFORM INFRARED SPECTROSCOPY

A Remote Sensing-Fourier Transform Infrared (RS-FTIR) system was applied to identify and quantify air contaminants along the beam, ranging from single compounds to mixtures, in various workplaces. Gas chromatography (GC) was used to provide information of point concentration variation by means of analyzing charcoal tube samples placed along the beam path. The results indicated a correlation between the charcoal tube-GC and the RS-FTIR for the analysis of most compounds. Discrepancies were found for some compounds, such as acetone, due to inhomogeneous concentration distributions along the IR beam, and due to the overlap of the acetone signal with off-scale water peaks. The study also demonstrated that there was little effect on quantitative analysis from partial or complete IR beam blockages during measurement. Qualitative analysis of unexpected compounds using RS-FTIR was also evaluated. In addition, the ability of the RS-FTIR to detect a sudden release of chemicals was demonstrated in the study.

GRAVIMETRIC DETERMINATION OF AIRBORNE DUST BY USING A FILTER CARTRIDGE INSIDE A CLOSED-FACE, 37-MM POLYSTYRENE CASSETTE

The current practice for the determination of personal exposures to airborne dusts involves the aspiration of known quantities of air through membrane filters held in filter holders. The two-piece, 37-mm polystyrene cassette is the most typically used filter holder. Two potential major errors exist with filter-based air-sampling methods. The first error is caused by potential sample loss on the inside of the cassette top during the samples collection and shipment back to the laboratory for analysis. A second error is caused by sample loss during the removal of the filter from the cassette prior to analysis. The potential for sample loss creates a third problem that is specific to gravimetric methods. A small linear range exists for gravimetric methods between their limit of quantitation and filter capacity. A new filter cartridge device was developed and evaluated to estimate the concentration of airborne total dusts over a larger linear range while eliminating negative bias errors associated with both s...

Field validation of passive dosimeters for the determination of employee exposures to ethylene oxide in hospital product sterilization facilities

Passive dosimetry has considerable advantages over active sampling for monitoring exposures to ethylene oxide (EtO), including reduced complexity, reduced cost, and increased sample stability. The major disadvantage of these methods is the conflicting data currently being reported in the literature regarding their ability to meet Occupational Safety and Health Administration (OSHA) method accuracy requirements at the 1 ppm permissible exposure limit (PEL). A field validation study was performed to determine the accuracy of three EtO passive dosimeters (3M-3550®, DuPont Pro-tek,® and AMSCO EO-Self-Scan®) and a common active method (Qazi-Ketchum [QK]) as area samples at four unique concentrations inside a hospital products sterilization facility. Collected at each location were 12 dosimeters of each type along with 12 QK tubes and hourly Tedlar® bag grab samples analyzed by gas chromatography with flame ionization detection (GC-FID). To enhance the strength of this study, manufacturers of EtO dosimeters wer...

Evaluation of Real-Time Techniques to Measure Hydrogen Peroxide in Air at the Permissible Exposure Limit

The major occupational concern from bio-decontamination of equipment using vapor phase hydrogen peroxide (VHP) generation systems is potential operator exposure outside the protective barrier from possible VHP leaks or accidental releases from the sealed piece of equipment during decontamination. For this reason, different real time monitoring techniques were evaluated to determine their ability to accurately measure VHP at concentrations ranging from 0.5 ppm to 5 ppm. The results of this laboratory evaluation suggest that two of the four methods evaluated (the ion mobility spectrometer [IMS] and Polytron) will approximate the National Institute for Occupational Safety and Health +/- 25% accuracy requirements for measuring the concentration of VHP at and near the Occupational Safety and Health Administration permissible exposure limit of 1.0 ppm. Over the range of 0.5 ppm to 5.1 ppm VHP, the IMS had an approximate pooled method accuracy of +/- 21%, while the Polytron had a pooled method accuracy of +/- 22%. However, both instruments had false readings when exposed to nominal concentrations of methanol, bleach, and sulfur dioxide. The two additional VHP monitoring techniques evaluated (the single point monitor [SPM] and Draeger tube) were unable to accurately measure the concentration of VHP when the relative humidity was below 20%.

A SHORT-TERM SOLID SORBENT DETERMINATION OF HYDRAZOIC ACID IN AIR

A sampling and analytical method for the measurement of hydrazoic acid (HN3) at the short-term ceiling limit was developed and validated under both laboratory and field conditions. The HN3 was collected on sodium hydroxide pretreated Orbo 52 silica gel tubes at a sampling flow rate of 1.0 L/min for 15 min. The samples were stored at room temperature until analyzed, and sample stability at 4 weeks was documented. The HN3 was desorbed with distilled water and the eluent was analyzed by high-pressure liquid chromatography with ultraviolet detection (210 nm). The desorption efficiency of HN3 from the Orbo 52 tubes was determined to be 96% over the 15-min time-weighted average concentrations of 0.025, 0.1, and 1.0 ppm HN3. The method limit of detection was determined to be 0.01 ppm. The coefficient of variation of the combined sampling and analytical method was 8.7%. A 2% method bias and total method accuracy of ±19% were estimated. The field validation of the method occurred over the concentration ranges of <...

Evaluation of a personal monitor employing an electrochemical sensor for assessing exposure to hydrogen peroxide in the workplace.

A commercially available direct-reading instrument designed for personal monitoring of vapor phase hydrogen peroxide (VHP) was evaluated in the laboratory and the workplace. Monitoring VHP has gained increasing importance in the pharmaceutical industry because sterilization using VHP has proven to be a good alternative to previously used sterilizing methods. The current Occupational Safety and Health Administration impinger method for VHP measurements, based on bubbling air through an acid solution with subsequent laboratory analysis, is not practical for monitoring personal exposures. By employing an electrochemical sensor, the instrument evaluated provides real-time exposure data with auxiliary functions such as displaying concentrations in parts per million, data logging, and alarms. A double-dilution technique using a syringe pump was used to generate dynamic test atmospheres ranging from 0.2 to 10 ppm in an exposure chamber. Time-weighted average concentration data from the direct-reading instrument was compared with concentration data from the impingers. The overall accuracy was less than the +/-25%, National Institute for Occupational Safety and Health criterion. No significant differences in accuracy were observed at three humidity levels (i.e., 15, 50, and 80%). The instrument was similarly evaluated in a workplace under typical conditions. The results agreed within +/-0.2 ppm. Selected performance characteristics of the instrument also were investigated, including reproducibility, response and recovery times, calibration frequency, and suitability of the calibration adapter. Results of the investigation suggest that the instrument provides a means for simple and accurate monitoring of personal exposures to VHP in workplace environments.

DEVELOPMENT AND VALIDATION OF A PROTOCOL FOR FIELD VALIDATION OF PASSIVE DOSIMETERS FOR ETHYLENE OXIDE EXCURSION LIMIT MONITORING

An exposure and analysis protocol is described for the field validation of passive dosimeters for ethylene oxide (EtO) excursion limit monitoring. The protocol calls for the use of a field exposure chamber with concurrent sampling using Tedlar air-sampling bags. The bags are analyzed immediately after sampling by gas chromatography with flame ionization detection (GC-FID). The chamber design allows all monitors to be exposed for the exact same time in the field. The sampling and analysis procedure not only determines the actual concentration of EtO present during the monitors exposure but estimates if concentrations of EtO vary from point to point in the monitor array during the exposure. In chamber operation, the accuracy of the standard generator used to calibrate the GC-FID was independently verified in the field by the standard additions method. The sampling bias of the sampling train was determined to be -3.5% in the 2.4 ppm to 14.3 ppm concentration range. To estimate the stability of collected EtO samples in Tedlar bags, the rate of EtO loss in the bags was determined to be 0.011 ppm/hr at 2.57 ppm and 0.066 ppm/hr at 8.07 ppm. Sampling bias of the passive methods by additional EtO exposure of the monitors in the closed chamber after sampling and during purging was determined to be +1.5%. The Tedlar bag sampling method with subsequent GC-FID determination demonstrated a coefficient of variation of 1.8% at 2.43 ppm.

Fourier transform infra-red spectroscopy applied to hazardous waste: I--Preliminary test of material analysis for improvement of personal protection strategies.

Many chemicals, when mixed, can produce potentially hazardous effects which are harmful to human health and to the environment such as heat, pressure, fire, explosion, violent reaction, and toxic dusts, mists, fumes, and/or gases. Waste chemicals handled on a remedial action site are analyzed by simple chemical methods for compatibility. Because it is difficult to base worker and community protection programs on this limited knowledge of material content, extreme precautions must be taken to ensure safety to all working on or living near hazardous waste remedial action sites. The approach used in this study involved the application of Fourier transform infra-red spectroscopy (FTIR) to the analysis of samples taken from the Chem-Dyne remedial action hazardous waste site. The data generated are compared to the results obtained using compatibility and GC-MS analysis procedures. Illustrations are given of improved personal protection strategies, based on drum material composition obtainable by FTIR. The requirements for further testing are defined.

Generation of Ethylene Oxide Permissible Exposure Limit Data with On-Site Sample Analysis Using the EO Self-ScanTM Passive Monitor

A sampling and analytical method is presented for the use of EO Self-ScanTM dosimeters for the determination of ethylene oxide permissible exposure limit (PEL) data. Analysis and report generation are performed on-site by trained personnel. A computer program for performing the calculations required to obtain accurate exposure data is described. The computer program is written in Microsoft BASICATM for use on MS-DOS based systems. The advantages and disadvantages of this method are described in detail.