Lab glass cleaning

Advice and tips for clean and residue-free lab glass and laboratory equipment - cleaning agents and cleaning process

1. com
Lab Glass Cleanin
g
.com
Advice for clean and residue
free
residue
-
free
laboratory equipment
© Dr. Weigert & DURAN Group 2012

2. Good
p
ractice
–
type
of
glass
.com
Good
p
ractice
type
of
glass
Selection of right types of glass a high quality of the raw materials and their
ii
compos
it
ion
wall thickness distribution in order to attain
a
g
ood resistance to tem
p
erature and
gp
changes in temperature, high level of mechanical stability

averyhighhydrolyticresistance

a
very
high
hydrolytic
resistance

(corresponds to class 1 according to ISO 719).
very small expansion coefficients, a high level
of resistance to quick changes in temperature
© Dr. Weigert & DURAN Group 2012

3. Good
p
ractice
–
conformity
to
standards
.com
Good
p
ractice
conformity
to
standards
•Why should attention be paid to conformity to
standards?

standards
set
thepropertiesand

standards
set
the
properties
and
geometries for laboratory glass products -> products can be still be obtained with the samecharacteristicsanddimensions same
characteristics
and
dimensions

even after many years
characteristics which are decisive for safety
such as distribution of wall thickness in
beakers, are given in the standards for many
articles
© Dr. Weigert & DURAN Group 2012

4. Good
p
ractice
–
instruction
for
use
.com
Good
p
ractice
instruction
for
use
•What is important when selecting a glass item for use? 
beforeeachusetheglasssurfaceshouldbe

before
each
use
the
glass
surface
should
be

checked for damage such as scratches,
cracks or chips

lhld lb dh h

vesse
ls s
h
ou
ld
on
ly
b
e use
d
w
h
en t
h
ey are in
a flawless condition, this is particularly
important for work under pressure or at high
temperatures
damaged glass may not be used for safety reasons.
© Dr. Weigert & DURAN Group 2012

5. Cleaning
–
cleaning
process
.com
Cleaning
cleaning
process
The advantage and disadvantages of
•manual cleaning
greater risk of injury
slower and less economical when there
arelotsofitemstobewashed are
lots
of
items
to
be
washed
time consuming when the laboratory
appliances have a complex geometry
is clearly quicker if only single laboratory
glass items are being cleaned

flexibleintermsofdurationofcleaning

flexible
in
terms
of
duration
of
cleaning

and selection of cleaning agent
© Dr. Weigert & DURAN Group 2012

6. Cleaning
–
cleaning
process
.com
Cleaning
cleaning
process
Advantages and disadvantages of •cleaning in a washer/disinfector 
reducedbreakagerisk

reduced
breakage
risk
reduced risk if injury
saves staff resources
quicker and more economical for
large quantities of items to be
washed washed

inflexible in terms of duration of
cleaning and selection of cleaning
agent
© Dr. Weigert & DURAN Group 2012

7. Cleaning
–
type
of
soiling
.com
Cleaning
type
of
soiling
Type of soiling
•Organic soiling
peptides/ proteins, fats/oils,
carbohydrates/ polysaccharides,
organiccolourings pigmentresidues organic
colourings
,
pigment
residues

and felt tip residues, resins and
paraffin
© Dr. Weigert & DURAN Group 2012

8. Cleaning
–
type
of
soiling
.com
Cleaning
type
of
soiling
Type of soiling
•Inor
g
anic soilin
g

gg
carbonates, salts, metal oxides,
waterysolutionsofinorganicacids
(
HCl
H
SO
)/
(
HCl
,
H
2
SO
4
)/

alkali(NaOH, KOH),
saltsolutions
(NaCl, NaNO
3
, FeCl
2
etc.)
© Dr. Weigert & DURAN Group 2012

9. Cleaning
–
typeofsoiling
.com
Cleaning

type
of
soiling
Type of soiling •Microbiolo
g
ical residue
g
growth media, cell cultures and
tissue residues, nutrient broth,
ii
m
icroorgan
isms
© Dr. Weigert & DURAN Group 2012

10. Cleaning
-
cleaningagents .com
Cleaning
cleaning
agents
Which cleaning agents are suitable for which soiling?
•Alkaline cleaning agents

it bl f th d t i d l

are su
it
a
bl
e
f
or
th
e
d
ena
t
ur
ing an
d
remova
l
of residues which contain protein, fat and
carbohydrates
•Acid cleaning agents are effective against inorganic salts,
lime and other carbonates.
•Bleaching agents help with the removal of paints and with disinfection.
© Dr. Weigert & DURAN Group 2012

11. Cleaning
-
cleaningagents .com
Cleaning

cleaning
agents
•What requirements must a cleaning agent meet? The selection is linked to the type of soiling to
bddthfkditi(ti b
e remove
d
an
d
th
e
f
ramewor
k
con
diti
ons
(ti
me,
material properties and mechanical system, quality
of water)
fundamental requirements:
good ability to remove dirt

highdirt
carryingcapacity
•Which resources can be used?
abrasive materials (steel wool)

high
dirt
-
carrying
capacity
suitable for most surfaces

g
ood rinsin
g
p
ro
p
erties
must not be used -> these will
cause surface damage to the
glass
ggpp
not hazardous to health
very cost-effective
soft sponges, cloths and brushes
are suitable
© Dr. Weigert & DURAN Group 2012
environmentally friendly

12. Cleaning
–
parameters
ofcleaning
.com
Cleaning

parameters
of
cleaning
•Chemistry (=cleaning agents) helps with the decomposition of dirt
tdthilifi
componen
t
s an
d
th
us s
imp
lifi
es
the removal of dirt from surfaces
the surfactants contained in cleaning
agents improve the wetting of the item
to be cleaned and the dirt-carrying
capac
ity
o
f
t
h
e
w
ate
r
capactyo t e ate
the selection of the cleaning agent to
be used depends on the dirt to be
removed thematerialoftheitemstobe removed
,
the
material
of
the
items
to
be
cleaned and the quality of water used for automated cleaning
© Dr. Weigert & DURAN Group 2012

13. Cleaning
–
parameters
ofcleaning
.com
Cleaning

parameters
of
cleaning
•Temperature high temperatures can accelerate physical,
hild ti d
c
h
em
ica
l an
d
enzyma
ti
c processes an
d

thus benefit removal of contaminations
temperatures which are too high can,
however, reduce enzyme activity
Another disadvantage of excessive temperature
ith i f b i id ti di is
th
e convers
ion o
f
car
b
on
ic ac
id
con
t
a
ine
d
in
the water to carbonate via hydrogen carbonate
which is then precipitated as a poorly soluble
compound with the water hardening salts magnesium and calcium. This results in stubborn ‘lime deposits’.
© Dr. Weigert & DURAN Group 2012

14. Cleaning
–
parameters
ofcleaning
.com
Cleaning

parameters
of
cleaning
•Time an extended reaction time for the
li lti kth l
c
lean
ing so
lu
ti
on ma
k
es
th
e remova
l
of dirt from the surface easier due
to better swelling of the contaminants
and a stronger chemical decomposition of the dirt components
© Dr. Weigert & DURAN Group 2012

15. Cleaning
–
parameters
ofcleaning
.com
Cleaning

parameters
of
cleaning
•Mechanics The use of mechanical agents such as the
fb h d
use o
f
b
rus
h
es or pressurize
d
water jets
enables bonding forces between dirt
and surface to be overcome so that
dirt can then be removed more easily.

Chemistry temperature timeandmechanicsarethefourcomponents

Chemistry
,
temperature
,
time
and
mechanics
are
the
four
components

of the so-called Sinner’s Circle which describes the mode of action of the
cleaning process and which was named after the chemist Dr. Herbert
Sinner Sinner
.
© Dr. Weigert & DURAN Group 2012

16. Cleaning
–
Dr.
Sinner
´
s
Circle
.com
Cleaning
Dr.
Sinner
s
Circle
Dr. Sinner’sCircle
Each parameter is variable in size. However, if one factor is changed this
will affect the size of at least one other factor if the cleaning performance
is to remain the same. This means that a longer reaction time is necessary if there is a lower temperature in the rinsing process for example. A reduced parameter is thus compensated by the increase of another.
© Dr. Weigert & DURAN Group 2012

17. Cleaning
–
qualityofwater
.com
Cleaning

quality
of
water
Quality of water defines
•microbiological factors (germ count)
•the degree of water hardness, given in °GH (German hardness)
(
magnesiumandcalciumionsinthewater
)
(
magnesium
and
calcium
ions
in
the
water
)
If water with a high degree of hardness is used for cleaning, significant
residues may be deposited on the cleaned surfaces
Depending on the water quality (e.g. deionised water or softened water)
different effects are achieved in combination with the used cleaning
agents. These affect the material compatibility and the cleaning results.
© Dr. Weigert & DURAN Group 2012

18. AdviceandTips
•
Howcanlaboratoryglassbestoredcorrectly
.com
Advice
and
Tips
•
How
can
laboratory
glass
be
stored
correctly

whilst saving as much space as possible?
•Marking –what has to be observed?
•How can stubborn residues be avoided?
•How should the glass be disposed of?
•
Whatshouldyouknowaboutvolumetric
•
What
should
you
know
about
volumetric

glassware?
•How should you clean cover glass and slides?
All this and more at
:
www.labglasscleaning.com
© Dr. Weigert & DURAN Group 2012

19. LaboratoryGlassCleaning
.com
Laboratory
Glass
Cleaning
From ex
p
erts for ex
p
erts
–
pp
© Dr. Weigert& DURAN Group 2012
www.labglasscleaning.com PicturesbyKarin
Gerdes
© Dr. Weigert & DURAN Group 2012
Pictures
by
Karin
Gerdes
http://www.karingerdes.de