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:
Toh Soh Lian
CM 2166/Expt 5
Quantitative Thin-Layer Chromatography: Photometry of an Eluate
A) Preparation of the dye:
OH
O
+
N N Cl
O
N N
OH
+
MW=99
O
O
270
312
Fast Red A1
C20H12O3N2
MW=328
B) To demonstrate TLC as a quantitative analytical method.
Chromatographic separation of the dye zones of the phenol derivative. The phenol derivative
eluted from the layer and the solution measured photometrically (UV spectrophotometer) at a
wavelength of 500nm.
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)
Electricity. Refer to prepared risk assessment on Use of Standard Electrical Equipment .
Phenol: 200mg
Toxic in contact with skin and if swallowed. Cause burns.
Fast Red AL Salt: 200mg
May be harmful or act as an irritant.
0.05M Sodium Hydroxide: 0.4ml
Danger! Corrosive. Causes skin burns. Causes eye burns. Causes digestive tract burns.
Causes respiratory tract burns.
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1M Hydrochloric Acid: 1ml
Causes severe burns. May be fatal if inhaled or swallowed. Vapor extremely irritating. May
cause damage to respiratory passages and lungs.
Chloroform: 16ml
Danger! May be fatal if swallowed, inhaled or absorbed through skin. Causes irritation to skin,
eyes and respiratory tract. May affect central nervous system, cardiovascular system, liver and
kidneys. Suspect cancer hazard. May cause cancer. Risk of cancer depends on level and
duration of exposure.
* Above amount stated are computed for the whole experiment.
Incompatible materials (special precautions):
Phenol:
Reactive with oxidizing agents, acids. Avoid aluminium(heat), aldehydes, halogens, nitrites,
nitrates, hydrogen peroxides, iron (III) compounds, salts of oxyhalogenic acids, peroxi
compounds, formaldehyde. Avoid heating.
Fast Red AL Salt:
Strong oxidants.
0.05M Sodium Hydroxide:
Incompatible materials, acids.
Reacts with mineral acids to form corresponding salts; reacts with weak acids gases like
hydrogen sulfide, sulfur dioxide, and carbon dioxide; ignites when in contact with
cinnamaldehyde or zinc; and reacts explosively with a mixture of chloroform and methane.
Corrosive to metals such as aluminum, tin, and zinc as well as to alloys such as steel, and may
cause formation of flammable hydrogen gas.
1M Hydrochloric Acid:
Conditions to Avoid: Heat, contact with metals
Materials to Avoid: Bases, alkalies and amines
Chloroform:
Strong caustics and chemically active metals such as aluminum, magnesium powder, sodium,
or potassium; acetone, fluorine, methanol, sodium methoxide, dinitrogen tetroxide, tert-butoxide,
triisopropylphosphine.
Conditions to Avoid: Light, heat, air and incompatibles.
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The risk of injury and its severity likely to arise from these hazards:
Phenol:
Inhalation: Mucosal irritations, coughing, dyspnoea, damage of respiratory tract.
Skin Contact: Burns. Danger of skin adsorption.
Eye Contact: Burns! Risk of blindness.
Swallowed: Burns in the mouth, throat, oesophagus and gastrointestinal tract.
Absorption: Headache, drowsiness, inebriation, confusion, unconsciousness, cardiovascular
disorders, changes in the blood picture, respiratory arrest, death.
Damage of liver, kidneys, heart.
Fast Red AL Salt:
The toxicological properties of this material have not been investigated. Use appropriate
procedures to prevent opportunities for direct contact with the skin or eyes and to prevent
inhalation.
0.05M Sodium Hydroxide:
Eye: Causes severe eye burns.
Skin: Causes skin burns. May cause deep, penetrating ulcers of the skin.
Ingestion: Causes gastrointestinal tract burns. Causes severe pain, nausea, vomiting, diarrhea,
and shock.
Inhalation: Irritation may lead to chemical pneumonitis and pulmonary edema. Causes severe
irritation of upper respiratory tract with coughing, burns, breathing difficulty, and possible coma.
Chronic: Prolonged or repeated skin contact may cause dermatitis.
1M Hydrochloric Acid:
Eyes: May cause irritation
Skin: May cause irritation
Ingestion: May cause gastrointestinal discomfort
Inhalation: May cause irritation to respiratory tract
Chloroform:
Inhalation: Acts as a relatively potent anesthetic. Irritates respiratory tract and causes central
nervous system effects, including headache, drowsiness, dizziness. Exposure to higher
concentrations may result in unconsciousness and even death. May cause liver injury and blood
disorders. Prolonged exposure may lead to death due to irregular heart beat and kidney and
liver disorder.
Ingestion: Causes severe burning in mouth and throat, pain in the chest and vomiting. Large
quantities may cause symptoms similar to inhalation.
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Skin Contact: Causes skin irritation resulting in redness and pain. Removes natural oils. May be
absorbed through skin.
Eye Contact: Vapors causes pain and irritation to eyes. Splashes may cause severe irritation
and possible eye damage.
Chronic Exposure: Prolonged or repeated exposure to vapors may cause damage to the
nervous system, the heart and the liver and kidneys. Contact with liquid has defatting effect and
may cause chronic irritation of skin with cracking and drying, and corresponding dermatitis.
Chloroform is a suspect carcinogen. Persons with pre-existing skin disorders or eye problems,
or impaired liver, kidney or respiratory function may be more susceptible to the effects of the
substance.
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
or risk. Wash 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/Safety.htm.
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:
Phenol:
Small Spill: Use appropriate tools to put the spilled solid in a convenient waste disposal
container.
Large Spill: Stop leak if without risk. Do not get water inside container. Do not touch spilled
material. Use water spray to divert vapor drift. Use water spray to reduce vapors. Prevent entry
into sinks or drainages. Eliminate all ignition sources. Call for assistance on disposal.
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Fast Red AL Salt:
Use proper personal protective equipment as indicated in Section 8 in the MSDS.
Clean up spills immediately, observing precautions in the Protective Equipment section in the
MSDS.
0.05M Sodium Hydroxide:
Absorb spills with absorbent (vermiculite, sand, fuller's earth) and place in plastic bags for later
disposal.
1M Hydrochloric Acid:
Ventilate area of spill. Eliminate all sources of ignition.
Remove all non-essential personnel from area. Clean-uppersonnel should wear proper
protective equipment and clothing. Absorb material with suitable absorbant and containerize for
disposal.
Chloroform:
Ventilate area of leak or spill. Wear appropriate personal protective equipment as specified in
Section 8 in MSDS. Isolate hazard area. Keep unnecessary and unprotected personnel from
entering. Contain and recover liquid when possible. Collect liquid in an appropriate container or
absorb with an inert material (e. g., vermiculite, dry sand, earth), and place in a chemical waste
container. Do not use combustible materials, such as saw dust.
Fire:
Phenol:
Flammable solid.
Suitable Extinguishing Media: Water, foam.
Small Fire: Use DRY chemical powder.
Large Fire: Use water spray or fog. Cool containing vessels with water jet in order to prevent
pressure build-up, autoignition or explosion.
Fast Red AL Salt:
As in any fire, Wear protective gear. During a fire, irritating and highly toxic gases may be
generated by thermal decomposition or combustion.
Extinguishing Media: Use agent most appropriate to extinguish fire.
0.05M Sodium Hydroxide:
Extinguishing Media: For small fires, use dry chemical, carbon dioxide, water spray or alcoholresistant foam.
1M Hydrochloric Acid:
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Extinguisher Media: Water spray.
Special Firefighting Procedures: Firefighters should wear full protective equipment and NIOSH
approved self-contained breathing apparatus.
Chloroform:
Slight fire hazard when exposed to high heat; otherwise, practically not flammable.
Explosion: Sealed containers may rupture when heated.
Fire Extinguishing Media: Use any means suitable for extinguishing surrounding fire.
Is the experiment suitable for out-of-hours operation ?
Yes
No
References if any:
http://www.chemdat.de/cdrl/catalog/standard/en/ (Cat no: 822296)
http://www.emdchemicals.com/analytics/doc/msds/msds-display.asp?materialid=PX0510
http://physchem.ox.ac.uk/MSDS/FA/fast_red_A1_salt.html
http://www.acros.be/ (Cat no: 19134)
http://www.jtbaker.com/msds/englishhtml/C2915.htm
http://www.alkemlab.com/pdf/msds/875275.pdf
http://www.carolina.com/STCMS/acrobat/stc_msds/POM_MSDS/Hydrochloric%20Acid.pdf
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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