Emerson Process Management OXYMITTER 4000 IM-106-340 - Manual (Page 165)

Instruction Manual
IM-106-340, Rev. 4.0
May 2006
A-17
Oxymitter 4000
EXPOSURE TO USED CERAMIC FIBER PRODUCT
Product which has been in service at elevated temperatures (greater
than 1800ºF/982ºC) may undergo partial conversion to cristobalite, a
form of crystalline silica which can cause severe respiratory disease
(Pneumoconiosis). The amount of cristobalite present will depend on
the temperature and length of time in service. (See Section IX for
permissible exposure levels).
SPECIAL TOXIC EFFECTS
The existing toxicology and epidemiology data bases for RCF's are still
preliminary. Information will be updated as studies are completed and
reviewed. The following is a review of the results to date:
EPIDEMIOLOGY
At this time there are no known published reports demonstrating
negative health outcomes of workers exposed to refractory ceramic
fiber (RCF). Epidemiologic investigations of RCF production workers
are ongoing.
1. There is no evidence of any fibrotic lung disease (interstitial fibrosis)
whatsoever on x-ray.
2. There is no evidence of any lung disease among those employees
exposed to RCF that had never smoked.
3. A statistical "trend" was observed in the exposed population between
the duration of exposure to RCF and a decrease in some measures
of pulmonary function. These observations are clinically insignificant.
In other words, if these observations were made on an individual
employee, the results would be interpreted as being within the
normal range.
4. Pleural plaques (thickening along the chest wall) have been
observed in a small number of employees who had a long duration of
employment. There are several occupational and non-occupational
causes for pleural plaque. It should be noted that plaques are not
"pre-cancer" nor are they associated with any measurable effect on
lung function.
TOXICOLOGY
A number of studies on the health effects of inhalation exposure of rats
and hamsters are available. Rats were exposed to RCF in a series of
life-time nose-only inhalation studies. The animals were exposed to 30,
16, 9, and 3 mg/m3, which corresponds with approximately 200, 150,
75, and 25 fibers/cc.
Animals exposed to 30 and 16 mg/m3 were observed to have
developed a pleural and parenchymal fibroses; animals exposed to 9
mg/m3 had developed a mild parenchymal fibrosis; animals exposed to
the lowest dose were found to have the response typically observed any
time a material is inhaled into the deep lung. While a statistically
significant increase in lung tumors was observed following exposure to
the highest dose, there was no excess lung cancers at the other doses.
Two rats exposed to 30 mg/m3 and one rat exposed to 9 mg/m3
developed masotheliomas.