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 Chuah Gaik Khuan
Activity being assessed:
Tan Lay San
CM3193/94
Organic Project
The Preparation of Butylated Hydroxytoluene via Fridel Crafts Alkylation
CH3
H3C
CH3
OH + H
C
+
H3C
CH3
C
C
+
H2O
OH
OH
H3C
+
CH3
OH
H
CH3
H
CH3
+
+
H3C
CH3
C
CH3
+
H3C
CH3
CH3
CH3
C
CH3
CH3
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)
Hotplate/Stirrer. Refer to prepared risk assessment on Use of Laboratory Heating
Equipment
3)
Electricity. Refer to prepared risk assessment on Use of Standard Electrical Equipment
4)
Rotary Evaporator, Pump. Refer to prepared risk assessment on Use of Reduced
Pressure or Vacuum
5)
Fume Hood. Refer to prepared risk assessment on Use of Fume Hoods
6)
Disposal of Pasteur pipettes. Refer to prepared risk assessment on Use and Disposal of
"Sharps"
7)
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.
Page 1 of 10
Printed on: 12 February 2016
4-Methylphenol (Hydroxytoluene, p-Cresol): 2.61 g (24.1 mmol)
Toxic!
Danger! May be fatal if inhaled, absorbed through skin or swallowed. Causes eye and skin
burns. Causes respiratory tract irritation. Contains material which causes damage to the
following organs: kidneys, liver, respiratory tract, skin, central nervous system, eye, lens or
cornea, pancreas.
Tert-butyl Alcohol (2-Methyl-2-Propanol): 5.6 mL or 4.4 g (60mmol)
Warning! Flammable liquid and vapor. Vapor may cause flash fire. Causes respiratory tract and
eye irritation. Causes damage to the following organs: respiratory tract, skin, central nervous
system, eye, lens or cornea. May be harmful if inhaled or swallowed. May cause skin irritation.
Glacial Acetic Acid: 1 mL
Extremely hazardous in case of eye contact (corrosive). Causes severe eye burns. Extremely
hazardous in case of skin contact (corrosive). Skin contact produces severe burns. Hazardous
in case of inhalation (lung irritant). Extremely hazardous in case of ingestion. May be fatal if
swallowed.
Highly flammable in presence of open flames, sparks and static discharge, of heat, of oxidizing
materials.
Concentrated Sulphuric Acid: 5 mL add dropwise
Extremely hazardous in case of eye contact (corrosive). Causes severe eye burns. Extremely
hazardous in case of skin contact (corrosive). Skin contact produces severe burns. Extremely
hazardous in case of inhalation. May be fatal if inhaled. Hazardous in case of inhalation (lung
corrosive). Extremely hazardous in case of ingestion. May be fatal if swallowed.
Diethyl Ether: 2 x 30mL
Danger! Extremely flammable liquid and vapor. Vapor may cause flash fire. May form explosive
peroxides. Harmful if inhaled or swallowed. Causes respiratory tract, eye and skin irritation.
Contains material which causes damage to the following organs: mucous membranes,
respiratory tract, skin, eyes, central nervous system, eye, lens or cornea.
2% Potassium Hydroxide: 10 mL
Warning! May be harmful if inhaled or swallowed. Harmful if absorbed through skin. Causes eye
irritation. May cause skin irritation. Contains material which causes damage to the following
organs: lungs, respiratory tract, skin, eye, lens or cornea.
Page 2 of 10
Printed on: 12 February 2016
Methanol (Anhydrous): 15 mL
Hazardous in case of eye contact (irritant). Inflammation of the eye is characterized by redness,
watering, and itching. Hazardous in case of skin contact (permeator, irritant). Skin inflammation
is characterized by itching, scaling, reddening, or, occasionally, blistering. Hazardous in case of
inhalation (lung irritant). Extremely hazardous in case of ingestion. May be fatal if swallowed.
Highly flammable & explosive in presence of open flames, sparks and static discharge, of heat,
of oxidizing materials. Flammable & explosive in presence of shocks.
Sodium Sulphate, Anhydrous: 2 – 3 g
May be hazardous in case of eye contact (irritant). May be hazardous in case of skin contact
(irritant). Skin inflammation is characterized by itching, scaling, reddening, or, occasionally,
blistering. May be hazardous in case of inhalation (lung irritant). May be hazardous in case of
ingestion.
*amount stated are computed for the whole experiment.
Incompatible materials (special precautions):
p-Cresol & Diethyl Ether
Reactive with oxidizing agents.
Tert-butyl Alcohol
Reactive with oxidizing agents, acids.
Glacial Acetic Acid
Substances to be avoided: Reactive with oxidizing agents, metals, alkalis.
Concentrated Sulphuric Acid
Extremely reactive or incompatible with reducing agents, combustible materials, organic
materials, metals, acids, alkalis, moisture.
2% Potassium Hydroxide
Highly reactive with oxidizing agents, organic materials, metals, acids.
Methanol
Highly reactive with oxidizing agents. Reactive with metals, acids.
Sodium Sulphate, Anhydrous
Not available.
The risk of injury and its severity likely to arise from these hazards:
Page 3 of 10
Printed on: 12 February 2016
p-Cresol
Eye: Hazardous in case of eye contact (corrosive). Causes eye burns.
Skin: Extremely hazardous in case of skin contact (permeator). May be fatal if absorbed.
Hazardous in case of skin contact (corrosive). Skin contact produces burns.
Inhalation: Extremely hazardous in case of inhalation. May be fatal if inhaled. Hazardous in
case of inhalation (lung irritant).
Ingestion: Extremely hazardous in case of ingestion. May be fatal if swallowed.
Tert-butyl Alcohol, Diethyl Ether & Methanol
Eye: Hazardous in case of eye contact (irritant). Inflammation of the eye is characterized by
redness, watering, and itching.
Skin: 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 (lung irritant). May be hazardous in case of
inhalation.
Ingestion: May be hazardous in case of ingestion.
Glacial Acetic Acid
Skin Contact: In case of contact, immediately flush skin with plenty of water for at least 15
minutes while removing contaminated clothing and shoes. Cold water may be used. Wash
clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention immediately.
Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing
is difficult, give oxygen. Get medical attention immediately.
Ingestion: If swallowed, do not induce vomiting unless directed to do so by medical personnel.
Never give anything by mouth to an unconscious person. Loosen tight clothing such as a collar,
tie, belt or waistband. Get medical attention immediately.
Concentrated Sulphuric Acid
Eye: Extremely hazardous in case of eye contact (corrosive). Causes severe eye burns
Skin: Extremely hazardous in case of skin contact (corrosive). Skin contact produces severe
burns.
Inhalation: Extremely hazardous in case of inhalation. May be fatal if inhaled. Hazardous in
case of inhalation (lung corrosive).
Ingestion: Extremely hazardous in case of ingestion. May be fatal if swallowed.
2% Potassium Hydroxide
Eyes: Hazardous in case of eye contact (irritant). Inflammation of the eye is characterized by
redness, watering, and itching.
Page 4 of 10
Printed on: 12 February 2016
Skin: Hazardous in case of skin contact (permeator). May be hazardous in case of skin contact
(irritant). Skin inflammation is characterized by itching, scaling, reddening, or, occasionally,
blistering.
Inhalation: May be hazardous in case of inhalation
Ingestion: May be hazardous in case of ingestion.
Sodium Sulphate, Anhydrous
Eye: May be hazardous in case of eye contact (irritant).
Skin: May be hazardous in case of skin contact (irritant). Skin inflammation is characterized by
itching, scaling, reddening, or, occasionally, blistering.
Inhalation: May be hazardous in case of inhalation (lung irritant).
Ingestion: May be hazardous in case of ingestion.
Who is at risk?
Persons handling the chemicals and as well as those present 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 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
Level of risk remaining:
The level of risk is low although constant vigilance is necessary to avoid injury.
Emergency action if :
Spill:
p-Cresol
Small Spill & Leak: Use appropriate tools to put the spilled solid in a convenient waste disposal
container.
Large Spill & Leak: Stop leak if without risk. Do not get water inside container. Do not touch
spilled material. Prevent entry into sink. Eliminate all ignition sources. Call for assistance on
disposal.
Page 5 of 10
Printed on: 12 February 2016
Tert-butyl Alcohol
Small Spill & Leak: Dilute with water and mop up, or absorb with an inert dry material and place
in an appropriate waste disposal container.
Large Spill & Leak: Keep away from heat. Keep away from sources of ignition. Stop leak if
without risk. If the product is in its solid form: Use a shovel to put the material into a convenient
waste disposal container. If the product is in its liquid form: Absorb with DRY sand or other noncombustible material. Absorb with an inert material and put the spilled material in an appropriate
waste disposal. Do not touch spilled material. Prevent entry into sink.
Glacial Acetic Acid
Small Spill & Leak: Dilute with water and mop up, or absorb with an inert dry material and place
in an appropriate waste disposal container.
Large Spill & Leak: Away from heat. Keep away from sources of ignition. Stop leak if without
risk. If the product is in its solid form: Use a shovel to put the material into a convenient waste
disposal container. If the product is in its liquid form: Cover with DRY sand or other noncombustible material. Absorb with an inert material and put the spilled material in an appropriate
waste disposal. Do not touch spilled material. Prevent entry into sink. Call for assistance on
disposal.
Concentrated Sulphuric Acid
Small Spill & Leak: Dilute with water and mop up, or absorb with an inert dry material and place
in an appropriate waste disposal container. If necessary: Neutralize the residue with a dilute
solution of sodium carbonate.
Large Spill & Leak: Stop leak if without risk. Cover with DRY sand or other non-combustible
material. Avoid contact with a combustible material (wood, paper, oil, clothing...). Do not touch
spilled material. Prevent entry into sink. Call for assistance on disposal. Neutralize the residue
with a dilute solution of sodium carbonate. Finish cleaning by spreading water on the
contaminated surface and allow evacuating through the sanitary system.
Diethyl Ether, Methanol
Small Spill & Leak: Dilute with water and mop up, or absorb with an inert dry material and place
in an appropriate waste disposal container.
Large Spill & Leak: Keep away from heat. Keep away from sources of ignition. Stop leak if
without risk. Cover with DRY sand or other non-combustible material. Do not touch spilled
material. Prevent entry into sink. Call for assistance on disposal.
2% Potassium Hydroxide
Small Spill & Leak: Dilute with water and mop up, or absorb with an inert dry material and place
Page 6 of 10
Printed on: 12 February 2016
in an appropriate waste disposal container. If necessary: Neutralize the residue with a dilute
solution of acetic acid.
Large Spill & Leak: Stop leak if without risk. Absorb with sand or other non-combustible
material. Do not touch spilled material. Prevent entry into sink. Call for assistance on disposal.
Neutralize the residue with a dilute solution of acetic acid.
Sodium Sulphate, Anhydrous
Small Spill & Leak: Use appropriate tools to put the spilled solid in a convenient waste disposal
container.
Large Spill & Leak: Use a shovel to put the material into a convenient waste disposal container.
Finish cleaning by spreading water on the contaminated surface and allow evacuating through
the sanitary system.
Fire:
p-Cresol
Small Fire: Use DRY chemical powder.
Large Fire: Use water spray, fog or foam. Do not use water jet.
Tert-butyl Alcohol, Diethyl Ether & Methanol
Flammable liquid, soluble or dispersed in water.
Small Fire: Use DRY chemical powder.
Large Fire: Use alcohol foam, water spray or fog. Cool containing vessels with water jet in order
to prevent pressure build-up, autoignition or explosion.
Glacial Acetic Acid
Small Fire: Use DRY chemical powder.
Large Fire: Use alcohol foam, water spray or fog. Cool containing vessels with water jet in order
to prevent pressure build-up, autoignition or explosion.
Concentrated Sulphuric Acid, 2% Potassium Hydroxide & Sodium Sulphate
Non-flammable.
Is the experiment suitable for out-of-hours operation?
Yes
No
References if any:

p-Cresol: http://www.sciencelab.com/msds.php?msdsId=9923572

tert-Butyl alcohol: http://www.sciencelab.com/msds.php?msdsId=9923195

Acetic acid: http://www.sciencelab.com/msds.php?msdsId=9922769

Sulfuric acid: http://www.ee.iitb.ac.in/~nanoe/msds/sulphuric%20acid.pdf
Page 7 of 10
Printed on: 12 February 2016

Diethyl ether: http://www.sciencelab.com/msds.php?msdsId=9923942

Potassium Hydroxide Solution:
http://sargentwelch.com/pdf/msds/Potassium_Hydroxide_Solution_0.1M_571.00.pdf

Methyl alcohol: http://www.sciencelab.com/msds.php?msdsId=9927227

Sodium sulfate anhydrous: http://www.sciencelab.com/msds.php?msdsId=9927278
Signature of Lab Officer in Charge:………………………………………………………………..
Date:…………………………
Signature of Lecture 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.
Page 8 of 10
Printed on: 12 February 2016
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.
Page 9 of 10
Printed on: 12 February 2016
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.).
Page 10 of 10
Printed on: 12 February 2016