Osh Case

The first instrument used was an MSA Solaris multigas detector. We carry the detector for use in confined space entry emergencies. Our detectors are equipped with sensors for oxygen, carbon monoxide, hydrogen sulfide and methane. Our primary use is to detect oxygen concentration. The device is set to alarm at 19.5% oxygen concentration for the low side and 23% on the high side. Methane alarm is 10% of the LEL, carbon monoxide is 35 ppm and hydrogen sulfide is 10 ppm. Calibration of the instrument is conducted annually by the plant metrology lab. The instrument is easy to use due to its small size but would be better with a wand that could extend the reach of the user.

All the employees in our area of the plant have to wear Thermoluminescent Dosimeters. These are attached to our badges and are designed to measure whole body dose from beta, x-ray or gamma radiation. They are exchanged every 3 months or in the event of a possible exposure. Administrative control levels at our facility are 1.0 rem/yr. In 23 years of employment my TLD has never shown an exposure.

We also carry Alpha and Beta detectors on our ambulances in the event we have a possibly contaminated patient. Our Alpha detectors are Ludlum Model 12’s set with a go/no go level of 2500 cpm. The Beta detectors are Ludlum Model 3’s with a go/no go level of 800 cpm.

I participated in a building survey with plant Industrial Hygiene technicians; the building had legacy mercury contamination. The device used was a Jerome 431-X which is the primary instrument utilized for mercury at our plant. The device was calibrated prior to use. The Jerome 431-X uses a strip of thin gold film that reacts in the presence of mercury causing an increase in electrical resistance proportional to the mass of mercury in the sample. The technicians went to several areas in the building and took readings. The action level for mercury at our plant is .125 milligrams per cubic meter, none of the samples taken registered any reading.

A type of photoionization detector used at our facility is the MiniRAE 2000. This detector uses a 10.6 electron volt bulb to detect for compounds. Isobutylene is the calibration gas used for this instrument. The MiniRAE 2000 has a library of compounds so if the material being monitored is known, such as benzene, a conversion factor can be used to arrive at a reasonably accurate reading in parts per million for the chemical. This device is generally used when checking areas when the chemical is unknown and a check is needed to determine the presence of a gas or vapors. We have numerous calls for the contents of unmarked/labeled drums to be checked for hazardous contents, this is the first instrument used before a sample is drawn.

The noise dosimeter used is the NoisePro DLX. It is a personal dosimeter that is carried by the employee to monitor exposure