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