biosafety & biosecurity

1. Safety and biosecurity
Lecture 4:-Biological agents
Dr. Raghda Saad Mohammed

2. Biological agents
 Biological agents are widely found in the natural
environment and as a result found in many work
sectors. They include bacteria, viruses, fungi
(including yeasts and moulds) and internal human
parasites (end parasites). The majority of these
agents are harmless however some may have
potential to cause ill health.

3. The Effects of Biological Agents
 As they are usually invisible, it is often difficult to
appreciate the risks they present. As a worker you
may be harmed by:
being infected by a biological agent,
being exposed to toxins produced by the biological agent,
or
having an allergic reaction to the biological agent or
substances it produces, for example, enzymes.
Biological agents have the ability to replicate rapidly,
require minimal resources to survive and can infect at very
small doses.

4. Types of Exposure
 In the workplace, exposure to biological agents can be
intentional, whereby the employee works directly with them, for
example, in a laboratory or research facility, or
unintentional, whereby the employee is exposed to the biological
agent due to the work they do, for example, a healthcare worker
who is exposed to a blood borne virus, a laundry worker who
receives a needle stick injury or a farmer who is exposed to an
animal disease that can also affect humans (a zoonose).

5. Routes of infection
One of the unfortunate consequences of working with biological hazards is the
potential for acquiring an infection. History has shown that such infections occur
and that laboratory workers are clearly at higher risk for infection with certain
agents, such as the hepatitis B virus, than the general population.
Although work-related infections can occur via routes that differ from those in
naturally occurring disease, there are limited routes of exposure and modes of entry
into the body. A worker exposed to an infectious aerosol could inhale respirable
particles. Larger droplets of that aerosol could fall on skin, mucous membranes, or
environmental surfaces. The worker could then inadvertently inhale or ingest the
agent without experiencing an overt accident. On the other hand, a needle stick or
an animal bite would usually be noticed. Providing awareness and barriers for these
routes of infection is a preventative approach to biosafety. The following are the
primary routes of transmission that can result in laboratory acquired infections.

6. 1. Injection (percutaneous)
1. Contaminated sharp objects (e.g. needle, scalpel)
2. Animal bites, scratches
3. Through broken or abraded skin (including rashes, eczema, split cuticles,
etc.)
2. Absorption (mucous membrane contact)
1. Splashes to the eyes, nose, mouth
2. Hand to face movements (i.e., applying cosmetics, cell phone usage, etc.)
3. Ingestion
1. Eating/drinking
2. Applying cosmetics
3. Contact with tear ducts
4. Inhalation (aerosols)
1. Liquid disturbance
2. Syringe preparation
3. Dried animal excretions
4. Leakage from injection site

8. Basic of control measures
 In the case of any activity in relation to which there is a risk to the safety
or health of employees caused by working with a biological agent, the
employer must take appropriate measures to ensure that:
1. Employees do not eat or drink in any location within a place of work
where there is a risk of contamination by a biological agent
2. Employees are provided with suitable washing and toilet facilities,
which may include eye washes and skin antiseptics (or both)
3. Employees are provided with suitable personal protective equipment
(PPE)

9. Basic of control measures
4. Any necessary PPE is:
a. properly stored in a designated place
b. checked and cleaned if possible, before, and in any case after each use
c. repaired, where defective, or replaced, before further use
5. Procedures are specified for taking, handling and processing samples of
human or animal origin
6. Working clothes and PPE, which may be contaminated by a biological
agent, are removed on leaving the working areas and, before taking
measures for cleaning/decontaminating/destroying, kept separately from
other clothing

10. Hazards groups classification system

11. Hazards groups classification system

12. Hazards groups classification system

13. CLASSIFICATION OF HAZARD
 The Globally Harmonized System (GHS) was developed by the
United Nations for international standardization of hazard
classification and communication.
 The GHS classification is divided as health, environmental and
physical hazards into separate classes such as toxicity, irritation,
sensitization, flammability, etc.
 The severity of the hazard within each class is described by the
category. The higher the category number, the lower the hazard.
 1) Health hazards :-
 Acute Toxicity (Category 1 through 4)
◦ Compounds in Category 1 through 3 are identified by the Skull and Cross
Bone pictogram. They are highly toxic in small amounts and can cause
serious health effects or death.
◦ Compounds in Category 4 are labelled with the Exclamation Mark symbol
(!). They are still harmful but cause lethal effects only after exposure to
large amounts.

14. CLASSIFICATION OF HAZARD
 Skin Corrosion / Irritation (Category 1 through 3)
◦ Compounds in Category 1 can cause severe skin damage. They are
marked with the Corrosion symbol.
◦ Compounds in Category 2 and 3 can cause reversible damage and are
labelled with the Exclamation Mark symbol.
 Eye Effects
◦ Compounds that can cause irreversible, serious eye damage are
classified as Category 1 and are marked with the Corrosion symbol.
◦ Eye irritants are classified as Category 2a and 2b. They can cause
reversible adverse effects and are labelled with the Exclamation Mark.

15. CLASSIFICATION OF HAZARD
 Sensitization
◦ Respiratory sensitizers that can induce hypersensitivity of the airways after
inhalation are marked with the Health Hazard symbol.
◦ A skin sensitizer that can induce an allergic response following skin contact
is labelled with the Exclamation Mark.
2) ENVIRONMENTAL HAZARD:-
 Acute and chronic aquatic toxicity
◦ A substance that can cause injury or other adverse effects to •aquatic
organisms with either a short-term or long-term exposure.
◦ Acute aquatic toxicity Category 1 and chronic aquatic toxicity Category 1
and 2 are labelled with the Environment symbol.

16. CLASSIFICATION OF HAZARD
3) PHYSICAL HAZARDS:-
 Corrosive to metals A substance that will react with and damage metals.
This class is marked with the Corrosion symbol.
 Explosives
◦ •A chemical that is by itself capable of producing gas at a temperature,
pressure, and speed that it can cause serious damage to the
surroundings.
◦ •Explosives are divided into groups 1.1 through 1.6 depending on
sensitivity.
◦ •Divisions 1.1 through 1.4 are labelled with the Exploding Bomb
symbol.

17. CLASSIFICATION OF HAZARD
Flammables
 All flammables are identified by the Flame symbol and
include:
◦ Gases: A gas having a flammable range in air under standard conditions
(20°C, 101.3 kPa).
◦ Liquids: A liquid having a flash point of not more than 93°C / 200⁰F.
◦ Solids: Solids that are readily combustible or may cause or contribute to
fire through friction. Depending on the burning rate flammable solids
are assigned to category 1 or 2.

18. CLASSIFICATION OF HAZARD
 Gases under pressure
•Gases that are contained in a receptacle at a pressure not less than 280 Pa
at 20°C or as a refrigerated liquid. They are identified by the Gas Cylinder
symbol.
 Oxidizing gases, liquids or solids
◦ •A chemical that in itself may not be combustible but causes or
contributes to the combustion of other materials. This class is marked
with a Flame Over a Circle symbol.

19. Thanks for
your
attention
12/10/2021 19