Ice Chests and Ice Machines
Investigations by the Center for Disease Control (CDC) have determined
that ice may become contaminated from use of impure water, contamination
of ice-making machines or from improper storage or handling of ice.
The following are CDCs recommended procedures to reduce the
likelihood of contamination of ice chests (ice storage compartments)
and ice machines:
- Ice machines that dispense ice directly into portable containers
at the touch of a control provide a more sanitary method to store
and obtain ice than use of ice chests, but such ice machines may
be more expensive to purchase and to operate.
- All ice handlers should be taught the following precautions:
- Wash hands frequently
- Hold scoop used with ice chest by handle; do not touch bowl
surface with hands
- Do NOT handle ice with hand
- Do NOT return unused ice to an ice storage chest
- Keep access doors to chests closed except when removing ice
- Ice scoops should be smooth, impervious and easy to clean. They
should be stored in a fashion that will preclude their contacting
the floor (tethered, in sleeve, stored in ice within the unit).
Scoops may also be kept on an uncovered, stainless steel, impervious
plastic or fiberglass tray on top of the chest when not in use.
The tray and the scoop should be run through a dishwasher or sterilized
- Remove all extraneous equipment and items from around or on
the ice chests and machines. If possible, limit access to ice
- Clean ice storage compartments on a preset schedule; weekly
to monthly cleaning of open chests is suggested; less frequent
cleaning may be possible with ice dispensing machines. Cleaning
should be carried out with a fresh soap or detergent solution
after disconnecting the unit, removing and discarding all ice
allowing the chest to warm to room temperature. Use clean
rags or disposable wipes to scrub all surfaces. Pay particular
attention to door tracks, guides and gaskets. After cleaning,
rinse all surfaces of the compartment with potable water, rinse
it again with a 100-ppm (mg/1) solution of hypochlorite, allow
it to dry and then return the unit to service.
- On an arbitrary schedule, perhaps monthly to quarterly, disconnect
ice-making machines, discard all ice and disassemble removable
parts of the machine. Thoroughly clean the machines and the parts.
Check for the need of possible repair of any portion of the machine.
Insure the presence of an air gap at all inlets for potable water.
Inspect for insect or rodent infestation under the unit and treat,
if necessary. Check the gasket around the ice chest door (open
compartment models) for cleanliness and evidence of possible leakage
or dripping of contaminants into the ice chest. Clean the ice
storage compartment as in No. 5 above. Place a 50-ppm of solution
of hypochlorite in the ice machine for at least 4 hours of a 200-ppm
solution for at least 2 hours. Circulate the solution throughout
the entire ice making and storing system according to the manufacturers
recommended cleaning and sanitizing procedures. Remove the disinfecting
solution, flush the system with potable water, allow the ice compartment
to dry and then return the unit to service.
Routine microbiologic sampling of ice from ice machines is recommended.
To sample, remove and melt ice aseptically and do quantitative plate
counts (or use membrane filter technique) on the resulting water;
possible pathogens should be identified, if present. If laboratory
service to conduct such evaluations is not readily available, ice
melted in a sterile container might be submitted to the local health
department in their water sampling bottles to determine whether
or not coliform contamination is present. Sampling for microbial
contamination on ice scoops could be conducted very occasionally
for educational purposes.