CMS SOM App. H, Tag V214

5.3.4 Bacterial control devices

5.3.4.1 Ultraviolet irradiators

Ultraviolet irradiators: When used to control bacterial proliferation in water storage and

distribution systems, UV irradiation devices shall be fitted with a low-pressure mercury

lamp that emits light at a wavelength of 254 nm and provides a dose of radiant energy of 30

milliwatt-sec/cm2, [except in the case described below]. The device shall be sized for the

maximum anticipated flow rate according to the manufacturer's instructions. [ANSI/AAMI

RD52:2004 requirements for UV irradiators intended for use in hemodialysis applications

directs users to RD62:2001, Section 4.3.13]

5.3.4.1 Ultraviolet irradiators

If the irradiator includes a meter as described above, the minimum dose of radiant energy

should be at least 16 milliwatt-sec/cm2.

To prevent the use of sublethal doses of radiation that may lead to the development of

resistant strains of bacteria, UV irradiators shall be equipped with a calibrated ultraviolet

intensity meter …or with an on-line monitor of radiant energy output that activates a

visible alarm, which indicates that the lamp should be replaced. Alternatively, the lamp

should be replaced on a predetermined schedule according to the manufacturer’s

instructions to maintain the recommended radiant energy output.

6.3.4 Bacterial control devices

6.3.4.1 Ultraviolet irradiators

Ultraviolet irradiators intended for use as a direct means of bacterial control shall be

monitored for radiant energy output. UV irradiators should be monitored at the frequency

recommended by the manufacturer. A log sheet should be used to indicate that monitoring

has been performed.

Interpretive Guidance § 494.40(a)

ANSI/AAMI RD52:2004

5.3.4 Bacterial control devices

5.3.4.1 Ultraviolet irradiators

[Equipment]

The recommendations provided in this clause concern UV irradiators used specifically for

bacterial control.

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Ultraviolet irradiators (also known as UV lights) may be used to control bacterial proliferation

in purified water storage and distribution systems. UV irradiators contain a low-pressure

mercury lamp that emits ultraviolet light at a wavelength of 254 nm. The lamp is housed in a

transparent quartz sleeve that isolates it from direct contact with the water. If the irradiator is

not fitted with a calibrated ultraviolet intensity meter that is filtered to restrict its sensitivity to

the disinfection spectrum and that is installed in the wall of the disinfection chamber at the point

of greatest water depth from the lamp, the dose of radiant energy provided by the lamp shall be

at least 30 milliwatt-sec/cm2.

6.3.4 Bacterial control devices

6.3.4.1 Ultraviolet irradiators

[Monitoring]

UV irradiators are available equipped with radiant energy intensity sensors. A visual alarm or

an output meter is acceptable for determining if the UV lamp is emitting sufficient radiant

energy.

Because the radiant energy decreases with time, annual lamp replacement is typically required.

Periodic cleaning of the quartz sleeve may also be required, depending on the water quality.

Additional Guidance:

Monitoring may be accomplished by any of the following options: use of a meter to monitor

intensity of the lamp, use of an on-line monitor that activates an alarm, or replacement on a

predetermined schedule.

The use of a UV irradiator in a bicarbonate distribution system may have a totally different role.

If ozone is used to disinfect that system, the UV irradiator may be used to break down the ozone.

If the UV irradiator is part of the bicarbonate distribution system, responsible staff must be able

to describe the intended purpose of the UV in that application. Monitoring of the irradiator is

still required, but there is no need to follow an irradiator used in the bicarbonate distribution

system with an ultrafilter or other endotoxin-retentive device.