Monitor work area

When it is necessary to monitor work areas or the intakes to ventilation systems, a highly sensitive system is desirable. 

A majority of eompanies - 60 pereent - said they monitored work areas for particles, but many said they swept and vacuumed those areas, apparently not realizing that those activities would result in nanoparticles being more widely dis-... 

Air Monitoring. The atmosphere in work areas is monitored for worker safety. Volatile amines and related compounds can be detected at low concentrations in the air by a number of methods. Suitable methods include chemical, chromatographic, and spectroscopic techniques. For example, the NIOSH Manual of Analytical Methods has methods based on gas chromatography which are suitable for common aromatic and aHphatic amines as well as ethanolamines (67). Aromatic amines which diazotize readily can also be detected photometrically using a treated paper which changes color (68). Other methods based on infrared spectroscopy (69) and mass spectroscopy (70) have also been reported. 

A variety of instmments are available to analyze carbon monoxide in gas streams from 1 ppm to 90%. One group of analyzers determines the concentration of carbon monoxide by measuring the intensity of its infrared stretching frequency at 2143 cm . Another group measures the oxidation of carbon monoxide to carbon dioxide electrochemically. Such instmments are generally lightweight and weU suited to appHcations requiring portable analyzers. Many analyzers are equipped with alarms and serve as work area monitors. 

The bench should be supplied with HEPA-filtered unidirectional airflow, having a velocity sufficient to sweep particulate matter away from the working area. Normally a velocity of 0.45 m s plus or minus 20% is adequate. It is important to monitor the air velocity at suitable intervals because significant reduction in velocity or uniformity in velocity can increase the risk of contamination. 

All monitoring systems have drawbacks because (1) the workers move in and out of the exposed workplace and (2) the concentration of toxicants may vary at different locations in the work area. Industrial hygienists play an important role in the selection and placement of workplace monitoring equipment and the interpretation of the data. 

Temperature and humidity is controlled to minimize evaporation of reagents and to keep performance of electronic equipment optimal. Ventilation is adequate for the removal of noxious fumes and odors. Formaldehyde and xylene vapor concentrations must be below maximum permissible levels. For formaldehyde, this level is 0.75 ppm for an 8-h time-weighted average, or 2.0 ppm for a 15-min short-term exposure. For xylene, the level is 100 ppm for an 8-h time-weighted average and 200 ppm for a 15-min short-term exposure. The monitoring of the work area and employees can be performed on a yearly basis. Chemical and biological safety cabinets are checked for proper airflow on a yearly basis. 

Room Activity/Works Area Position for Routine Monitoring Position for Intensive Monitoring Frequency Alert Limit Action Limit... 

The PhRMA Environmental Monitoring Work Group published an article in the March 1997 issue of Pharmaceutical Technology on microbiological monitoring of environmental conditions for nonsterile manufacturing [4]. This publication is a compilation of survey results of nonsterile manufacturing facilities within the United States and recommendations based on the survey results. In this section, a summary of the survey results and recommendations pubhshed in this article are reviewed with a few comments from this author based on experiences in this area. 

Diverse instruments employing the principle of this experiment are used to measure mercury, a toxic and volatile element, present in many work areas. A device has been designed as a colorimeter dedicated for this single element. The source is a mercury vapour lamp and the cell is a transparent tube filled with the atmosphere to be monitored. If mercury vapours are present in the optical path, absorption of radiation emitted by the lamp will occur and this will lead to a decrease in the transmitted light intensity measured by the instrument. 

Figure 4-1. Diagram of work area of a proposed pharmacy-run anticoagulation monitoring clinic.

These devices are now being tested in demilitarization plants as monitors of stack exhaust atmospheres and work areas. We have not had the opportunity to determine the sensitivity of the devices to the numerous enzyme-inhibiting compounds which would be of interest to others. Generally, however, it is reasonable to expect, for instance, less sensitivity to P=S and P—S linkages and conversely better sensitivity to compounds where the sulfur is replaced by oxygen due to greater toxicity of these compounds. Such compounds as the carbamates, due to their inhibiting qualities, would also be expected to be detected with these systems. 

Methods and monitoring equipment used for detecting presence or release of hazardous chemicals in the work area. 

Monitor your working area frequently for contamination. 

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