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Lesson 3
Hazardous Chemical Management

Module Chair: Cherry Chan

Last updated on: 23/4/2025
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Learning Objectives
1. Describe the roles of the four authorities (MOM, NEA, SCDF, SPF) involved in regulating
Hazardous Chemical Management in Singapore
2. Identify the hazards and classifications of chemicals by using Safety Data Sheet (SDS) and
Globally Harmonized System of Classification and Labelling of Chemicals (GHS) pictograms for
safe use of chemicals.
3. Describe the four considerations (containment methods, chemical compatibility/ incompatibility
using compatibility charts, labelling/good documentation practice (GDP) and storage methods) for
safe chemical and chemical waste storage.
4. Apply the correct SOP and GDP to safely identify, handle, label chemicals for proper storage for
examples of chemicals given.

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Activity 1: The Curious Intern

You are an intern working in a chemistry lab.

You discover several unlabeled chemical
bottles on your first day.
• What questions should you ask?
• What should you do?

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Chemical
Chemical
Any substance with a defined composition,
whether naturally occurring or man-made.
Example: water (H₂O) always consists of two
hydrogen atoms and one oxygen atom.

Non Hazardous Hazardous/Toxic

• Do not pose significant risk to • Can cause harm to human,

health, safety, or the animals, property, or the
environment under normal usage environment
• Still requires proper handling and • Defined by
disposal in laboratories • Physical hazard
• Health hazard
• Environmental Hazards
Can you name some
• Requires proper handling and
examples of chemicals? disposal
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REGULATION
• Define the Environmental Protection and Management Act (EPMA) of
Singapore.
• Identify and explain the role of four authorities (MOM, NEA, SCDF, SPF)
involved in regulating Hazardous Chemical Management in Singapore

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Use of Hazardous Chemicals in Singapore

The Environmental Protection and Management Act (EPMA), Chapter 94A is Singapore's principal
legislation for regulating environmental pollution and hazardous substances. It is administered by
the National Environment Agency (NEA) and covers air, water, and land pollution, as well as the
management of hazardous substances and waste
Link: https://sso.agc.gov.sg/Act/EPMA1999

In terms of hazardous substances, the act ensures PROPER:

1 Storage

2 Usage

3 Dealings

This ensures risks to individuals and the environment is minimised.

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Authorities Involved in Hazardous

Chemical Management
MOM NEA
Ministry of National
Manpower Environment
Agency

Authorities

SPF
SCDF
Singapore
Singapore Civil
Police Force
Defence Force

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Ministry of Manpower (MOM)

Role: Ensures workplace safety and health concerning hazardous chemicals under the
Workplace Safety and Health Act (WSHA). (recall Lesson 2)

Knowledge
• Oversees competency training
Hazards Communication programs (e.g., bizSAFE, Chemical
Safety Courses).
• All hazardous chemicals must
be clearly labelled using the Key
Globally Harmonised System Responsibilities
(GHS)
Proper storage, handling, and disposal
• Employes must ensure that
Safety Data Sheets (SDS) are • Mandates risk assessments and safety
available and accessible to all measures for hazardous chemicals.
employees • Regulates chemical exposure through
• Workers must be informed Permissible Exposure Limits (PELs).
and trained on chemical • Implements control measures like ventilation
hazards in their work area. and Personal Protective Equipment (PPE).
• Signages and communication • Conducts inspections and investigates
tools incidents involving hazardous chemicals.
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National Environment Agency (NEA)

Role: Regulates environmental pollution and hazardous substances under the Environmental Protection
and Management Act (EPMA)

Chemical/toxic
Licensing and Monitoring and
waste management
Regulations enforcement
and disposal

• Issues licenses for • Regulates the safe • Conducts inspections and

hazardous substances disposal and treatment environmental testing
• Sets environmental of chemical waste • Enforces compliance
standards and discharge • Ensures compliance through audits and
limits with environmental penalties
protection laws

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Singapore Civil Defence Force (SCDF)

Role: Ensures emergency preparedness and fire safety involving hazardous materials under the Fire Safety Act.

Fire Safety Issues fire safety permits

Regulation and regulates storage
requirements for
flammable and hazardous
chemicals.
Conducts audits, drills,
and training for Inspection
emergency preparedness and
and chemical safety Training
compliance.

Emergency Responds to and mitigates

Response HazMat incidents, including
chemical spills and fires.

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Singapore Police Force (SPF)

Role: Regulates the security and control of regulated explosive precursors and dangerous chemicals under the
Arms and Explosives Act

Controls the access, storage, Monitors and investigates suspicious

and transport of regulated activities or misuse of hazardous chemicals,
hazardous substances to especially those with potential security
prevent misuse. threats.

Chemical Security Licensing of Investigation and

Regulation Controlled Chemicals Enforcement

Issues licenses for the

import, storage, and use of
explosive precursors and
controlled chemicals.
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HAZARDS
IDENTIFICATION AND
CLASSIFICATIONS
Identify the hazards and classifications of chemicals by using
• Safety Data Sheet (SDS), and
• Globally Harmonized System of Classification and Labelling of Chemicals
(GHS) pictograms for safe use of chemicals.

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Commonly Used Chemicals in the Laboratory

Hydrochloric acid Methanol Sodium hydroxide

Dimethyl sulfoxide Ethidium bromide

Acetonitrile Sulphuric acid

Acetone Ethanol

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Globally Harmonised System (GHS)

The Globally Harmonised System of Classification and Labelling of Chemicals (GHS) is a system for chemical hazard
communication.

The United Nations developed the GHS through standardised:

• Chemical hazard classification
• Chemical product labelling
• Safety Data Sheets (SDS)

In this system, chemical hazards are classified based on the type of hazards cause:

• Physical hazards can be subdivided into 16 hazard classes.

• Health hazards can be subdivided into 10 hazard classes.
• Environment hazards can be subdivided into 3 hazard classes.

Each of these hazard class is further divided into different hazard category. Note that a lower category number
indicates a more hazardous nature of the chemical.
Link to subdivided hazard classes: https://pubchem.ncbi.nlm.nih.gov/ghs/ 14
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GHS and Labelling of Chemicals

Consistent chemical hazard communication

GHS

GHS
pictograms

Chemical Chemical
Safety Data
Hazard Product
Sheets (SDS)
Classification Labelling

Identify
chemical hazard Communicate chemical hazard
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GHS Pictogram

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Safety Data Sheet (SDS)

Safety Data Sheet (SDS) includes information such as:
• properties of each chemical
• physical, health, and environmental health hazards;
• protective measures; and
• safety precautions for handling, storing, and transporting the
chemical.

It provides guidance for each specific chemical on things such as:

• Personal Protective Equipment (PPE)
• First aid procedures
• Spill clean-up procedures

Safety Data Sheet (SDS) must be reviewed:

• Within 5 years from the date of issue.
• When there is new information or change in properties of the
chemical. An example of SDS

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Activity 2: Interpretation of SDS

Let’s take a look at the SDS of sulphuric acid.

Click the 2 resource link to view the SDS of 2 suppliers of sulphuric acid.
Each chemical supplier must issue its own SDS for each chemical.

Resource from:
1. LabChem CAEN_LC25550_SDS.pdf

2. Merck https://www.merckmillipore.com/SG/en/product/msds/MDA_CHEM-480364?Origin=PDP

With reference to the SDS of sulphuric acid from the 2 suppliers:

1. List the 16 sections in each SDS.
2. Identify the GHS pictogram, signal word and hazards associated with the use of sulphuric acid?
3. What are the preventive measures to minimise the hazards associated with the use of sulphuric acid?
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CHEMICAL AND
CHEMICAL WASTE
STORAGE
Describe the four considerations for safe chemical and chemical waste storage
• containment methods,
• chemical compatibility/ incompatibility using compatibility charts,
• labelling/good documentation practice (GDP) and
• storage methods

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Correct Containment of Chemicals for Storage

When storing chemicals:
store chemicals:

In proper containers Breakable chemical containers should By compatibility first, Away from sources of heat
be stored in a secondary container then by alphabetical order

Segregated away from In properly labelled specially All chemical containers should be Equip chemical storage areas
incompatible chemicals designed cabinets for storage. dated when received or opened with facilities for emergency
Cabinets for should be clearly response
labelled on the hazardous nature
of the content.
Eg. flammable, toxic etc
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Wrong containment of Chemicals for Storage

store chemicals:
On the floor In fume hood Excessive quantity of
chemicals

Odorous chemicals, may disrupt

At risk of being walked into airflow of the hood and cause More chemicals might cause
or knocked over/hit vapors to travel back into the larger cost in disposing unused
laboratory environment chemicals

Above eye-level On laboratory benchtops

Contents can splash onto Knocked over, or not protected

face when containers fails or from a laboratory fire
breaks
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Chemical Classification For Storage

For storage of chemicals, SIX groups are important to take note of:

Corrosive Flammable Gaseous

Oxidizers Reactive Toxic (Severe)

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Importance of Chemical Compatibility

When incompatible chemicals are place next to one another this may results in adverse reactions when in contact,
leading to hazards such as:

Heat Fire Explosion Toxic gas Flammable Greater

generation toxicity
corrosives and corrosives and corrosive acid and corrosives and corrosives and chlorine and
water flammables corrosive alkali plastic metals ammonia

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Determining Chemical Compatibility

To determine Chemical Compatibility, we should refer to:

Chemical Compatibility Matrix Safety Data Sheet (SDS)

serves as a general guideline to determine should also be referred to determine
chemical compatibility handling and storage requirements

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Chemical Compatibility Matrix

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An example of a Chemical Compatibility Matrix
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How to read a Chemical Compatibility Matrix

Step 1

Step 2
Step 3
Step 1: Identify the Group of
the 1st chemical hazard for
storage (eg: Hydrochloric Acid is an inorganic
acid)

Step 2: Identify the Group of the

2nd chemical hazard for storage
(eg: Sodium Hydroxide also known as caustic soda is
a caustic (group 3))

Step 3: Look for the intercepting

point to identify chemical
compatibility

In this example, hydrochloric acid and

sodium hydroxide are not compatible to
be stored together.
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Good Documentation Practice (GDP)

Good Documentation Practice (GDP) is a set of principles and standards used to ensure that documentation is
accurate, consistent, and traceable — especially in regulated environments like laboratories, chemical handling,
pharmaceuticals, and workplace safety.

GDP Is Important Because:

•Ensures safety and accountability
•Enables compliance with Singapore laws (e.g., WSH Act, EPMA)
•Provides an audit trail in case of inspections or incidents
•Supports good communication among staff and departments

In Singapore, GDP is especially important for:

•chemical handling and storage
•safety audits and inspections
•regulatory compliance with agencies like MOM, NEA, and SCDF

GHS chemical labelling is an example of good documentation practice.

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GHS Chemical Product Labelling

GHS labels must follow a standardized
labeling format.
• They are to be affixed on all
chemical packages and workplace
chemical containers with
hazardous chemicals.
• It allows individuals to identify the
chemicals they are handling and 1. Product name 2. GHS Pictogram
most importantly the hazards Chemical ABC
involved and the precautionary Danger
measures to take. 3. Signal word
Causes skin burns and eye 4.Hazard statement
damage
There are 7 items required in a GHS
label. 5. Precautionary Wear protective gloves

1. Product identifier, statement 6. Supplementary

For other information, refer to
2. GHS pictogram, SDS information
3. Signal word, Company XYZ
4. Hazard statement, 7. Supplier xxxxxxxx
5. Precautionary statement, information
6. Supplementary information
7. Supplier information
All these information can be obtained from the SDS of the chemical. 28
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Label Dimensions
Dimensions required:

Capacity of container Dimensions (in millimetres)

125ml – 3 litres If possible, at least 52 X 74

Greater than 3 litres but not exceeding
At least 74 X 105
50 litres
Greater than 50 litres but not exceeding
At least 105 X 148
500 litres
Greater than 500 litres At least 148 X 210

Are labels required for chemicals that

are transferred and stored in
containers less than 125mL?

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Reduced Workplace Labels

Reduced workplace labels for chemicals in containers of ≤125ml.
• Allowed in the laboratory for chemicals that are transferred into secondary containers of 125 milliliters or lesser in volume.
• They can be sent for research and analysis but should not be supplied to another workplace.

There are 2 items required in reduced workplace labels namely the

1. Product identifier
2. GHS pictograms.

1. Product name Sulphuric acid

2. GHS Pictogram

Example of reduced workplace label: 30

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Activity 3: Create a label

With reference to this SDS of sulphuric acid, create GHS

labels for:
 500mL bottle of sulphuric acid
 100mL bottle of sulphuric acid

Resource from:
LabChem https://labchem.com/ASSETS/DOCUMENTS/ITEMS/EN/CAEN_LC25550_SDS.pdf
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Chemical and Chemical Waste Storage

Safe chemical storage practices can Chemicals should not be
reduce the risk of injury or exposure,

Stored haphazardly Damage to property

Stored in alphabetical order

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SOP AND GDP ON HOW

TO HANDLE CHEMICALS
• Apply the correct SOP and GDP to safely identify, handle, label
chemicals for proper storage for examples of chemicals given.

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SOP and GDP on Handling Chemicals

Identification of Unknown Safe Handling of Chemicals Labeling (GDP compliant and GHS Storage and Compatibility
Chemicals •Always wear the required PPE: aligned) •Segregate chemicals by hazard
•Do not assume chemical identity • Lab coat, gloves Label all containers clearly and class:
based on appearance, smell, or (material based on legibly using permanent ink or •Store in clearly labeled,
container type. chemical), safety printed labels. dedicated cabinets
•Quarantine unlabeled chemicals goggles or face shield. •Use secondary containment
in a designated “Unknown” zone. •Use fume hoods or ventilation Secondary containers (e.g. trays to catch leaks or spills.
•Refer to: when handling volatile or dropper bottles, working flasks) •Ensure all storage areas have
• Chemical inventory hazardous substances. must also be labeled, even if warning signs
records •Never eat, drink, or touch your temporarily used. •Avoid storing chemicals above
• SDS (Safety Data face while handling chemicals. eye level or on the floor.
Sheets) •Avoid working alone when •Lock cabinets for highly
• Labels or logs from handling unknown or hazardous hazardous or controlled
previous users chemicals. substances.
•If identification is uncertain,
contact the Safety Officer for
chemical testing or safe disposal.
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Exit Ticket: The Curious Intern Part 2

You are an intern working in a chemistry lab. You notice a small glass bottle containing a yellowish liquid. The
label is faded, partially peeled, and missing hazard information. Your colleague mentions, “I think it’s nitric acid,
but not 100% sure.”
The chemical is currently stored beside a bottle of acetone and a container of sodium hydroxide, all on an open
shelf with no spill tray or signage.

As a trained lab personnel, apply the appropriate SOP and Good Documentation Practice (GDP) to address the
following:
1.Identification:
• What steps should you take to confirm the identity of the chemical?
• Why is it important not to assume the identity based on appearance or memory?
2.Handling:
• What personal protective equipment (PPE) should be used to safely assess or move the bottle?
• What precautions should be taken before moving the chemical?
3.Labeling:
• What information must be included on the new label according to GHS and GDP standards?
4.Storage:
• Evaluate if the current storage is appropriate.
• How should the chemical be stored based on its hazard class?
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What you have learnt

 Describe the roles of the four authorities (MOM, NEA, SCDF, SPF) involved in
regulating Hazardous Chemical Management in Singapore

 Identify the hazards and classifications of chemicals by using Safety Data Sheet
(SDS) and Globally Harmonized System of Classification and Labelling of
Chemicals (GHS) pictograms for safe use of chemicals.

 Describe the four considerations (containment methods, chemical compatibility/

incompatibility using compatibility charts, labelling/good documentation practice
(GDP) and storage methods) for safe chemical and chemical waste storage.

 Apply the correct SOP and GDP to safely identify, handle, label chemicals for
proper storage for examples of chemicals given.

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