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.
A/P Jaenicke Stephan
Activity being assessed:
Tan Lay San
CM 2161/Expt 1

Distillation of methyl cyclohexane & n-heptane

Fractional distillation of a ternary mixture of n-pentane, n-hexane & n-heptane with the
bubble tray column
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.
List of activities involved in this experiment which inevitably entail risks. The following are the
activities being use:
1)
Glass Apparatus. Refer to prepared risk assessment on Use of Glassware
2)
Syringes with needles, Pasteur pipettes. Refer to prepared risk assessment on Use and Disposal of
"Sharps"
3)
Refractometer with water bath, Heating Mantle. Refer to prepared risk assessment on Use of
Laboratory Heating Equipment
4)
Electricity. Refer to prepared risk assessment on Use of Standard Electrical Equipment
5)
Waste disposal: All organic waste have to be disposed of in the appropriately labelled waste
container placed in a secondary containment housed under the designated fume hood.
Methyl Cyclohexane: 105ml
Flammable liquid and vapour. Vapour may cause flash fire. May be harmful to environment if
released in large amounts. Harmful if inhaled or swallowed. Causes damage to the following
organs: Respiratory tract, skin, central nervous eye lens or cornea. May cause eye and skin
irritation.
n-Heptane: 115ml
Flammable liquid and vapour. Vapour may cause flash fire. Harmful if inhaled or swallowed. May
be harmful to environment if released in large amounts. Aspiration hazard. Causes respiratory
tract, eye and skin irritation. Causes damage to the following organs: Respiratory tract, skin,
central nervous system.
n-Hexane: 50ml
Extremely flammable liquid and vapour. Vapour may cause flash fire. Aspiration hazard if
swallowed- can enter lungs and cause damage. Harmful if inhaled or swallowed. Causes
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respiratory tract, eye and skin irritation. Causes damage to the following organs: Peripheral
nervous system, respiratory tract, skin, central nervous system, eye, lens or cornea.
n-Pentane: 50ml
Extremely flammable liquid and vapour. Vapour may cause flash fire. May be harmful to
environment if released in large amounts. May be fatal if swallowed. Aspiration hazard (lung
irritant). Harmful if inhaled. Causes damage to the following organs: Lungs, respiratory tract,
skin, central nervous system, eye, lens or cornea. May cause respiratory tract, eye and skin
irritation. Repeated exposure may cause skin dryness or cracking.
* Above amount stated are computed for the whole experiment.
Incompatible materials (special precautions):
All above chemicals are highly reactive with oxidizing agents.
The risk of injury and its severity likely to arise from these hazards:
Methyl Cyclohexane:
Eye Contact: May be hazardous in case of eye contact (irritant).
Skin Contact: May be hazardous in case of skin contact (irritant). Skin inflammation is
characterized by itching, scaling, reddening, or, occasionally, blistering.
Inhalation: Hazardous in case of inhalation.
Ingestion: Hazardous in case of ingestion.
n-Heptane:
Eye Contact: Hazardous in case of eye contact (irritant). Inflammation of the eye is
characterized by redness, watering, and itching.
Skin Contact: Hazardous in case of skin contact (irritant). Skin inflammation is characterized by
itching, scaling, reddening, or, occasionally, blistering.
Inhalation: Hazardous in case of inhalation (lung irritant).
Ingestion: Hazardous in case of ingestion. Aspiration hazard if swallowed- can enter lungs and
cause damage.
n-Hexane:
Eye Contact: Hazardous in case of eye contact (irritant). Inflammation of the eye is
characterized by redness, watering, and itching.
Skin Contact: Hazardous in case of skin contact (irritant). Skin inflammation is characterized by
itching, scaling, reddening, or, occasionally, blistering
Inhalation: Hazardous in case of inhalation (lung irritant). Danger of serious damage to health
by prolonged exposure through inhalation. Possible risk of impaired fertility.
Ingestion: Hazardous in case of ingestion. Aspiration hazard if swallowed- can enter lungs and
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cause damage.
n-Pentane:
Eye Contact: May be hazardous in case of eye contact (irritant).
Skin Contact: May be hazardous in case of skin contact (irritant). Skin inflammation is
characterized by itching, scaling, reddening, or, occasionally, blistering.
Inhalation: Hazardous in case of inhalation. May be hazardous in case of inhalation (lung
irritant).
Ingestion: Extremely hazardous in case of ingestion. May be fatal if swallowed.
Who is at risk?
Persons handling the chemicals as well as 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.
Please
refer
to
PSSO
Safety
Information
Centre
website
on
safety
measures:
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.
Please
refer
to
Completed
Risk
Assessment
on
Common
Activities:
http://www.chemistry.nus.edu.sg/PSSO/safety/risk/risk.htm#Common
Level of risk remaining:
The level of risk is low although constant vigilance is necessary to avoid injury.
Emergency action if :
Spill:
Small Spill: Absorb with an inert material and put the spilled material in an appropriate waste
disposal.
Large Spill: Keep away from heat. Keep away from sources of ignition. Stop leak if without risk.
Absorb with DRY earth, sand or other non-combustible material. Do not get water inside
container. Do not touch spilled material. Call for assistance on disposal.
Fire:
Small Fire: Use DRY chemical powder.
Large Fire: Use water spray or fog. Cool containing vessels with water jet in order to prevent
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pressure build-up, autoignition or explosion. Water must never be used on an electrical fire.
Is the experiment suitable for out-of-hours operation ?
Yes
No
References if any:
Methyl Cyclohexane: http://www.sciencelab.com/msds.php?msdsId=9924678
n-Heptane: http://www.sciencelab.com/msds.php?msdsId=9924237
n-Hexane: http://msds.chem.ox.ac.uk/HE/hexane.html
n-Pentane: http://www.sciencelab.com/msds.php?msdsId=9926418
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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