622-Hygiene / 748
H
ygiene
BOS-PRD-0304.900902
quality and protecting public health. Frequent testing for these faecal indicators is still the most sensitive and
specific way of assessing the quality of potable water.
H
ydroc
a
r
b
ons
Test for hydrocarbons is conducted due to the potential for cross contamination with fuel and oil.
C
hl
orides
Legislative limits <250 mgCl/l.
Test for chlorides is conducted due to the potential for cross contamination with sea water.
T
o
ta
l V
i
ab
l
e Coun
t
(
TV
C)
The original guideline for acceptable levels of bacterial contamination in mains/drinking water was laid down
by the World Health Organisation (WHO) to be no more than 100 cfu/ml at 22°C and 10 cfu/ml at 37°C.
WHO now consider this to be an unrealistic restriction and suggests that the TVC trend is monitored for any
abnormal change.
For an indication of the general condition of the water, a TVC at 22°C and 37°C check will be taken on each
sample. The results should show
no
ab
nor
m
a
l
c
h
a
nge
.
In order to measure this, the results
should
be trended and analysed with reference to the historical levels
achievable within that vessel, Company or area, depending on the information available.
L
egione
ll
a
The danger of infection caused by Legionella bacteria is caused when it gains entry to the respiratory
system. This can occur from water suspended in air in the form of a fine mist as created by showers or tap
sprays.
Maintenance of cargo potable water tanks, pipe work, pumps and hoses as defined in these guidelines
should
control any contamination by Legionella in the water carried.
Should
an operator require cargo potable water to be tested for Legionella the following test limit applies:
T
es
t
L
i
m
i
t
Legionella <
10
3
cfu/l (cfu = colony forming units).
If the level of alert is > 10
3
cfu/l, vessel will need to:
x
Verify the origin of the deviation compared to the results obtained previously;
x
Strengheting the hygienic measures and controls.
If the level of alert is > 10
4
cfu/l, the vessel will need to:
x
Schedule a technical intervention to eliminate the risks: prohibite any risky situation (shower…);
x
Implement immediate curative measures such as desinfectation, heat shock, etc…
4
.
7
.
2
W
a
r
m w
at
er
ins
ta
ll
at
ion
The temperature of the outlet at warm water systems
shall
be at least 60
q
C. The identification and assessing
of the risk
should
focus on areas where this could not be reached.
Measures
should
be taken to improve the system (i.e. to increase the temp. setting of the boiler.) Or
measures
should
be taken to control this risk (i.e. the system
shall
be heated up to 60ºC temperature for at
least 20 minutes every week).
Version 04. Original date: 25/05/2012. Version date: 31/12/2014. Valid version only on QMS site. Uncontrolled document when printed.
Procedure prepared by: BOS QHSE Coordinator. Approved by: BOS QHSES Manager. Validated by: BOS Quality Representative
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