Viji Vijayan
Assistant Dean
Safety, Health and Emergency Management
President
Biorisk Association of Singapore
Singapore - small island state in South East
Asia
Total area 716.1 sq km
Population 5.54 mill
Work force 3.5 mill
Unemployment 2%
Per capita GDP SGD 71,000
• Established in 2005, first US-style graduate-entry
medical school
• Annual enrolment of over ~ 60 medical students
• Strong PhD program
• Over S$280 million in grants
• 1,400 peer-reviewed journal articles
• Five wet bench lab based programs
• Co-located – Singapore’s largest healthcare group –
augments translational research
Analysis of New Risks Posed by
Biological Waste and Mitigation
Methods
Outline:
• Biological waste definition
• Cradle to grave concept
• Challenges
• Potential solutions
Definition:
Any waste that is generated in the diagnosis, treatment,
or immunization of human beings or animals; in
biological research; or in the production or testing of
biologicals
There is no globally agreed upon definition of medical
waste, healthcare or healthcare-related facility.
Life cycle of waste material
Research laboratory
Purchase, storage,
use
Waste generation
Storing waste
Transporting waste
Final disposal
Life cycle of waste material
Have a plan
Before you open
Color coding for waste
Clearing of the waste with
transport
Clearing of the waste with
transport
Special waste disposal for hazmat
Purchase, storage,
use
Waste generation
Storing waste
Transporting waste
Final disposal
Risk at every stage of the life cycle of waste
In our School:
• Biological
o liquid waste or solid waste
o infective and non infective
• Radioactive disposed as solid
• Chemical mostly liquid
• Toxic liquid and solid
• General solid
Cost for 50 labs
• Solid biological waste 240 L bins annually
2670 bins costing SDG 80,100
• Per L SGD 0.125
• General Waste 660L bins 3650 bins annual
SGD 68,500
• Per L SGD = 0.028
4.5 times more expensive
• Medical/Biological waste most expensive
• What constitutes medical waste
• Primary objective is to minimize the risk of infection
• As much as 50% of waste is general waste
• This results in unnecessarily high disposal costs
• Improved segregation - substantial savings
Waste Hierarchy
There are four tiers to waste management:
1. at source reduction
2. reuse or redistribution
3. treatment, reclamation, and recycling of materials
within the waste
4. disposal through incineration, treatment, or land
burial
First tier at source reduction
• Segregation at source
• should have a good strategy
• training
• clear instructions
• Decontaminating at source to dispose as general waste
• Risk assessment of the waste
Clearing of the waste with
transport
Education and Communication
Second tier is to reuse unwanted material, redistribute
surplus chemicals, and reduce hazards.
• purchasing only what is needed
• sharing material
• keeping inventories to prevent the purchase of
duplicates
• sewer disposal of certain aqueous liquids, based on
regulations
Third tier
recycling material that can be recovered safely
“waste-to-energy”
Examples: silver from film processing solutions
The fourth tier
Incineration and landfill – incineration reduces the
volume but can produce toxic gases
Non incineration methods like autoclaving do not reduce
the volume
The incineration of solid waste reduces its volume by about
90%.
Singapore has four waste-to-energy plants
this has helped land-scarce Singapore to reduce her need
for future landfills, hence creating a sustainable waste
management framework
Waste-to-energy
The heat from the combustion process is used to
generate superheated steam in boilers. The steam is
in turn used to drive turbo generators to produce
electricity
Ferrous scrap metal contained in the ash is
recovered
In Singapore the ash is used for laying roads
New types of waste
• nanomaterial
• synthetic material
• biological mixed with the above
Nanomaterials
particles of approximately 1-100 nm range
Nanoparticle are produced in countless process like
erosion, combustion, volcanic eruptions in addition
they are used in cosemetics, paints, fabric.
Some of the applications of nanoparticles used for
biology they form a part of biological waste
Nanowaste has not yet triggered legislative
amendments
Most places dispose them as chemical
waste
Regulatory re-classification may influence
management practices
Concern over nano-objects exhibiting
increased toxicological properties
Incineration can release toxic material
Dealing with unknown materials
• simple steps for newer chemicals and material
• simple in-laboratory test procedures by trained
persons
• some basic information and hazard classification
• err on the side of some caution when assessing the
risk
• precise molecular structure not necessary for waste
management
My message today
• Waste Management starts when you order any
material
• Risk Assessment should include waste management
• Segregation and decontamination at source
• Sharing to reduce duplication
• Waste-to-energy