DEPARTMENT OF CHEMISTRY
TEACHING LAB EXPERIMENT RISK ASSESSMENT FORM
This form must be completed jointly by the Lab Officer in charge and the Lecturer in charge. A
hardcopy of the completed form should be kept in a file together with the Project Risk
Assessment.
Name of Lecturer in Charge
Name of Lab Officer in Charge
Module / Expt No.
Prof Lam Yulin
Activity being assessed:
Tan Lay San
CM1101/ 2
Chemical Kinetics : Rate of an Iodine-clock Reaction
Known or expected hazards associated with the activity:
Hazards of reagents, solvents and known reaction products.
State each substance and the approximate amounts to be used/produced.
See Appendix 1.4
Incompatible materials (special precautions):
Potassium persulphate : strong oxidizer, avoid contact with combustible materials, may cause fire.
The risk of injury and its severity likely to arise from these hazards:
Low level of risks.
Who is at risk?
Person performing the experiment and those in the vicinity
Measure to be taken to reduce the level of risk:
Proper laboratory attire and safety measures must always be used in order to reduce the level
of risk. Wash hands thoroughly after handling. Do not take internally. Eye wash and safety
equipment should be readily available.
Eye protection: Chemical safety goggles.
Hand protection: Gloves.
Refer to prepared PSSO SAFETY Information Center website:
http://www.chemistry.nus.edu.sg/PSSO/index.htm#undergrad
Training prerequisites:
This assessment should be read by everyone who will be using the above mentioned
chemicals.
Refer to Completed Risk Assessment forms for common activities:
http://www.chemistry.nus.edu.sg/PSSO/safety/risk/risk.htm#Common
Use of Glassware
Use of Standard Electrical Equipment
Use of Laboratory Heating Equipment
Level of risk remaining:
Low but constant vigilance should be maintained to avoid injuries.
Emergency action if :
Spill:
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(i)
(ii)
(iii)
Eyes : Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the
upper and lower eyelids. Get medical aid.
Skin : Wash affected area with water for 10mins. Remove contaminated clothing.
Consult physician if necessary.
Bench: Spillages on the work bench should be mopped up with a piece of cloth
immediately.
Fire: not a fire hazard.
Is the experiment suitable for out-of-hours operation?
Yes
No
References if any: Refer to the following MSDS for more information
Potassium iodide: http://www.sciencelab.com/msds.php?msdsId=9927571
Potassium persulphate : http://www.sciencelab.com/msds.php?msdsId=9927234
Sodium thiosulphate : http://www.sciencelab.com/msds.php?msdsId=9927606
Starch indicator, 1% : http://www.sciencelab.com/msds.php?msdsId=9926916
Oxalic acid : http://www.sciencestuff.com/msds/C2193.html
Potassium permanganate: http://www.sciencelab.com/msds.php?msdsId=9927406
Signature of Lab Officer in Charge:………………………………………………………………..
Date:…………………………
Signature of Lecturer in Charge:………… ……………………………………..
Date:… ……………………..
Prepared Risks Assessments for standard equipment and operation are with the kind permission of Dr. Ken MacNeil,
School of Chemistry, University of Bristol.
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Activity being assessed:
Note any activity to be used which entail risk (e.g. use of glass vacuum apparatus, high pressures, high
voltage, radiation, high temperatures). Give reference to any special protocols to be followed, and if
appropriate attach copies to the risk assessment form. State any additional precautions taken to minimise
risk.
Known or expected hazards associated with the activity:
FOR EACH CHEMICAL, read the MSDS and note:a) Particular hazards (e.g. highly toxic, carcinogenic, corrosive, flammable, pyrophoric, explosive, volatile,
dust hazard). Note any dangerous combinations of properties (e.g. volatile and toxic).
b) Requirements for safe handling (e.g. fume cupboard, inert atmosphere, low temperature).
c) How to dispose of residuals
 Dispose to drain, with water dilution
 Neutralise, then to drain with suitable dilution
 To flammable liquid waste receptacle
 To non-flammable liquid waste receptacle
 Keep for recovery/recycling
 Keep for special disposal later (e.g. heavy metals)
 Double bag and dispose to dry waste
 Special procedure (specify)
Incompatible materials (special precautions)
Note any dangerously incompatible materials and hazards arising from contact of any reagents and
substances used with common materials such as paper, benches, hoses, etc.
Measures to be taken to reduce the level of risk
Include hazards of previously unknown products.
Location of work – laboratory, open bench, fume cupboard
Level of risk remaining:
Likelihood and consequences of any accident or unforeseen events whilst carrying out the activity. When
this has been done, choose the appropriate procedure:a) Close supervision and/or attendance of trained first-aider needed.
b) Specific approval of supervisor needed.
c) Training is needed prior-to or during the operations specified.
d) Training is complete and only general laboratory competence required.
e) No risk perceived.
Emergency action:
a) Any special requirements to deal with accidental spillage or leakage.
b) What to do in the event of accidental exposure (skin contact, inhalation, etc.).
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Appendix 1.4
Reagents
Potassium iodide
Concentration Amount used
0.2M
80mL
Pot. persulphate
0.1M
80mL
Sod. thiosulphate
0.0033M
50mL
Starch
1%
10mL
Oxalic acid
0.3M/2M
H2SO4
0.1M
30mL
Pot. permanganate
30mL
Expected hazards
May cause irritation to
eyes, skin and
respiratory tract.
Strong oxidizer. May
cause burns to eyes and
skin.
May cause irritation to
skin and eyes.
May cause irritation to
skin and eyes.
Corrosive, causes severe
burns to eyes and skin.
Irritating to skin and
eyes.
Treatment/Disposal
Wash spillages away
with plenty of water.
Avoid combustibles.
Wash spillages away
with plenty of water.
Wash spillages away
with plenty of water.
Wash spillages away
with plenty of water.
Wash spillages away
with plenty of water.
Determination of rate order and rate constants
2I+
( ~4mmol)
S2O82-
I2
+
2SO42-
I2
(~1mmol)
2S2O32-
2I-
+
S4O62-
+
Investigation of the temperature effect on a chemical reaction
2MnO4- +
(~1mmol)
5C2O42-
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+
16 H+
2Mn2+
+
10 CO2
+ 8H2O