OSHA Hazard Information Bulletins
December 23, 1986
MEMORANDUM FOR REGIONAL ADMINISTRATORS
| THRU: | JOHN MILES
Director
Directorate of Field Operations |
| |
| FROM: | EDWARD BAIER
Director
Directorate of Technical Support |
| |
| SUBJECT: | Health Hazard Information Bulletin: Potentially Hazardous Amoebae Found in Eyewash Stations |
Region VI has brought to our attention a Department of Energy (DOE) bulletin
indicating that Acanthamoebae, small amoebae capable of causing serious eye
infections, have been found in numerous portable and stationary eyewash
stations at several DOE facilities.
The infections caused by Acanthamoebae are difficult to recognize and treat
and may result in loss of the infected eye. Acanthamoebae are able to
survive conventional water plant treatment regimens, and clinical treatments
with most antibiotics are ineffective against this amoeba.
Control by chlorination of the water (with a free residual of 25 ppm) has
been tested and found to be effective in destroying Acanthamoebae. However,
corrosion of the equipment occurred in some of the stainless steel eyewash
stations. One-minute and three-minute flushings of the units were also
tested. One-minute flushing was not effective in reducing the number of
Acanthamoebae; three-minute flushings drastically reduced the number of
positive samples.
Acanthamoebae are ubiquitous in tap water. The water can be tested using
the method outlined at the end of this bulletin. In most instances the
number of amoebae present will not be significant, but they proliferate in
stagnant, residual water and then become dangerous. Until other control
methods are investigated, such as the optimal level of chlorination, we
recommend that the following DOE guidelines be used:
1. Plumbed eyewash units should be flushed for at least three
minutes weekly to reduce Acanthamoebae and to verify proper
operation.
2. Self-contained eyewash stations should not be used in areas
where a continuous source of potable water is available. They should be used
only in remote areas where installation of a portable water system is not
economically feasible. The water in self-contained eyewash stations should
be changed weekly.
3. In general, squeeze bottles should not be used except where the
hazard severity or distance from plumbed eyewash equipment requires personal
equipment at work stations for immediate flushing prior to prolonged flushing
at a plumbed or self-contained unit.
Compliance and consultation personnel should be aware of the possibility
that eyewash stations filled with or connected to portable water supplies may
be contaminated with the Acanthamoebae. Please disseminate this information
to Area Offices, State Plan States, and Consultation Project Officers.
Method for testing water for Acanthamoebae:
i. Filter water samples through 1.2 micrometer cellulose membranes
ii. Invert filters and place on non-nutrient agar plates coated with
iii. Incubate at 37 deg. C for 2-3 days which is the time necessary for amoebae outgrowths
iv. Observe trophozoites and cysts for morphology indicative of
Acanthamoebae.
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