Continuing Respirator Effectiveness

The employer is required to address in its written program the type of regular surveillance of the workplace necessary to evaluate the effectiveness of the respirator program. Other items discussed in the standard include  

Consult the complete body of the document for complete information. 

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Continuing respirator effectiveness, (i) Appropriate surveillance shall be maintained of work area conditions and degree of employee exposure or stress. When there is a change in work area conditions ordegree o f employee exposure or stress that may affect respirator effectiveness, the employer shall reevaluate the continued effectiveness of the respirator. 

Respirators prevent the inhalation of harmful airborne substances and provide fresh air in oxygen-deficient environments. An effective respiratory protection plan must address the following (1) hazards encountered, (2) type and degree of protection needed, (3) medical evaluation for respirator usage, (4) selection and fit requirements, (5) training on use and care, and (6) methods to ensure continued program effectiveness. 

The effect of rifaximin on cardiovascular (CY) and respiratory systems was investigated in anesthetized rats and guinea pigs, respectively [59]. Rifaximin was given intraduodenally at doses up to 100 mg/kg and carotid pressure and flow as well as heart rate were continuously measured in rats while respiration amplitude and frequency were monitored in guinea pigs. The rifamycin derivative did not affect any of the measured parameters at any time after its administration. 

Continuous culture systems of aerobic treatment are likely to be more cost effective since in steady state conditions the respiration rate and hence oxygen requirement, remain constant. This report describes the effects of mean treatment time, treatment temperature and dissolved oxygen level in aerobic continuous culture systems on the removal of odorants from piggery slurry and on the heterotrophic oxygen demand during treatment. 

No MRLs were derived for inhalation exposure to phenol. Human inhalation studies of phenol alone were not identified. Inhaled phenol is a respiratory irritant in animals and decreased respiration rate in mice by 50% during a 5-minute exposure at 166 ppm (De Ceaurriz et al. 1981). Based on their studies in mice, De Ceaurriz et al. (1981) estimated that a level of 2 ppm would be aNOAEL for respiratory effects in humans. A study in rhesus monkeys, rats, and mice did not find significant effects following a 90-day continuous exposure at 5 ppm (Sandage 1961). Intermittent exposure of guinea pigs and rabbits to 26-52 ppm phenol resulted in severe respiratory, cardiovascular, hepatic, and renal toxicity (Deichmann et al. 1944). Similar effects were not observed in rats exposed in a similar manner. 

Depth profiles from the eastern tropical North Pacific (Figure 24.8) show the effects of nitrogen metabolism under 02-deficient conditions. The thermocline is characterized by a sharp decline in O2 concentrations that coincides with increasing nitrate and phosphate concentrations. The oxycline is produced by the respiration of sinking POM under vertically stagnant conditions. Below the oxycline, in depths where O2 concentrations are suboxic, phosphate concentrations continue to increase, but at a slower rate. In contrast, nitrate concentrations decline and reach a mid-water minimum that coincides with a nitrite maximum. The latter is referred to as the secondary nitrite maximum. (At this site the primary nitrite maximum is located at 50 m.)... 

Some articles, for example, include an identical table of effective and lethal doses of high potency Fentanyl derivatives. The estimated safety margins are as high as 30,000. I could find no source for these data. I sent out several inquiries but thus far have received no definitive answers. I also discussed the questions with Harry Salem, who continues to study the toxicology of opioids at Edgewood. He is hopeful that the concomitant use of drugs tailored to suppress the effect of potent opioids on respiration may produce much safer agents. 

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