Transcript CHEMICAL HAZARDS AND PREVENTION

CHEMICAL HAZARD AND
PREVENTION
FIRDAUS ALI
BSc (Health and Safety), Curtin University,
Perth Australia
Objectives of this session

Understand the key definitions and fundamental concepts of
chemical hazards

Identification of chemical hazard and route of exposure

Describe the worksite assessment process

Identify the hierarchy of control measures
Spot the hazard
Key Definitions
Hazard
A situation that poses a level of threat
to life, health, property or environment
Risk
The chance of something happening that will
have an impact on life, health, property
or environment
(AS/NZS 4360:2004)
Exposure
Defined as the contact over time and space
between a person and one or more
biological, chemical or physical agents
based on frequency, magnitude and
duration
(US Nuclear Regulatory Commission,
1991).
Toxicology
Defined as the study of
adverse, and potentially
adverse, effects of
chemicals which have, or
may have, the capacity
to cause injury to living
organisms.
"Dosis facit venenum" The Dose Makes the
Poison
All substances are
poisons; there is none
which is not a poison.
The right dose
differentiates a
poison…." Paracelsus
(1493-1541)
Dose
The dose of a hazardous substance is
generally expressed with the following
equation:
Dose = concentration (level) x duration of exposure.
This is a fundamental principle on which
occupational exposure limits (OELs) are
based
Toxicity
Refers to its capacity to
injure if it reaches a
susceptible site on the
body. Whether ill-effects
will occur depends on:
The properties of the
chemical
 The dose (amount of
chemical acting on the
body)
 The susceptibility or
resistance of the exposed
individual
 The route by which the
substance enters the body

Identification of Chemical Hazard
Substances which can be inhaled, or are respirable, include
gases, vapours and aerosols, may be defined as follows:

GASES: substances which normally exist in gaseous
form at standard pressure and temperature

VAPOURS: the gaseous form of substances normally
liquid at standard pressure and temperature

AEROSOLS: suspensions of variable size particles
capable of remaining airborne
Dusts – caused by mechanical abrasion or
fragmentation of solids
 Fumes – produced by combustion,
sublimation or condensation of volatile
solids.
 Smokes – suspension of solid particles
produced by incomplete combustion of
organic materials
 Mists – airborne droplets usually formed by
condensation of vapours but may be
produced by atomisation of a liquid

Chemicals That Present Hazard or Risk
◦ Flammability: catch fire readily; gasoline
◦ Reactivity: unstable and may explode or
create toxic fumes when mixed with water;
explosives, concentrated sulfuric acid
◦ Toxicity: injurious to health; pesticides,
chlorine
Material Safety Datasheets
A document containing important information
about a hazardous chemical (which may be
hazardous substance and/or dangerous
goods) and must state:

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


a hazardous substance's product name
the chemical and generic name of certain
ingredients
the chemical and physical properties of the
hazardous substance
health hazard information
precautions for safe use and handling
Chemical Groups
International Version published by the WHO
and European Union
Available at:
http://www.ilo.org
Safety Label
Available at:
http://www.cdc.gov/niosh
Legislation on Chemical Safety
Poison Act, 1956
 Disaster Management Order, 2006
 Workplace Safety and Health Order, 2009

Available at:
http://www.agc.gov.bn
Route of Exposure
The Respiratory System
A large range of vapours and gases, dusts,
fumes can enter the respiratory tract
through inhalation
Odours - danger lies in using chemicals
which have no odour, or where toxicity
occurs before odour is detected. People
who have had a long term exposure to a
chemical tend to ignore the smell
 Dusts - Many dust particles are small enough
to enter the alveoli air pockets where they
can cause damage

The Skin
The protective properties of the skin can be
reduced by exposure to chemicals such as
degreasers, detergents, and solvents

Chemical exposure can result in dryness,
splitting and cracking and damage to the skin
surface

Sensitivity to chemicals can cause allergic
reactions - in rare circumstances can cause
death
The Eyes
Some chemicals have very strong vapours
that can cause acute discomfort to the
eyes.
 Exposure to these types of fumes can
cause permanent damage to the eyes.
 Care must be taken to protect from
splashes as well as fumes

The Gastro - Intestinal Tract
Usually due to poor housekeeping, dusty
environments and the close proximity of
toxic airborne substances to eating
facilities.
 Poor hygiene practices (not washing
hands before eating & not wearing gloves
when dealing with chemical) can also
prove hazardous

Potential Chronic Health Problems
Occupational Asthma (Glutaraldehyde)
 Carcinogen (Ethylene oxide and
Cyctotoxic Drugs)
 Kidney Failure (Lead fumes)
 Lung Fibrosis (Diesel) ?

WORKSITE ASSESSMENT PROCESS
Direct health indicators (worker
complaints, illness statistics, biological or
radiological signs before symptoms occur)

Previous experience and information
(MSDS, material inputs, the process, the
pattern of exposure, work procedures)


Walk-through survey (5 P’s; People, Premises, Process,
Product, Personal Protective Equipment)

Specific Site

Specific Task
Risk Assessment
Systematic process for describing and
quantifying the risks associated with
hazards including substances, processes,
action or events.
The overall process of risk identification,
risk analysis and risk evaluation
(AS/NZS 4360:2004).
Hazard
Risk & Health
Consequence
Poor lifting techniques of
patients and equipment
(over 20 kgs)
Musculoskeletal Injuries
-Lumber Disc Protrusion
-Back Injury
Improper recapping of
needles
Needlestick Injuries
-Bloodborne diseases
(HIV, Hepatitis B)
Chemical handling on
Glutaraldehyde (Cidex) for
disinfecting endoscopy and
operating theatre
instruments
Respiratory problems
-Occupational Asthma
-Contact Dermatitis
Chemical handling on Glutaraldehyde (Cidex) for
disinfecting endoscopy and operating theatre
instruments
Exposure
Occupational Risk
Exposure
Limits (OELs)
8 hours
<0.2ppm
Low
>0.2ppm
High
PPE in place
(hand gloves,
face guard, face
mask)
Fume window
closed
8 hours
PPE not in place
Fume window
open
Control measures
5 steps of hierarchy of control measures
 Elimination (Remove)
 Substitution (Replace)
 Engineering Control (Remodel/Renovate)
 Administrative/Procedural Control
(Reinforce)
 Personal Protective Equipment (last
Resort)
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Elimination
Depends!
-Detrimental effect on human body
-Demand of the product

Substitution
-Replace with a less hazardous substance
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Engineering Control
-Fume Cupboard (Grading for different types of
chemical handling/performance)
-Ventilated room with back vent
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Administrative/Procedural Control
-Education and Training
-Legislation
-Standard Safety Procedure (Chemical Handling)
-MSDS
-Incident Report
-Regular medical checkup

Personal Protective Equipment
Different types of chemical have different
use on each equipment
-Hand Gloves
-Face Guard/Mask
-Safety Apron/Safety Suit
-Rubber Boots
-Helmet ?
SCENARIO
You as an Occupational Health Nurse have been advised to
investigate an incident in the endoscopy unit. It was reported
that 10 healthcare workers have been suffering from acute
exacerbation of asthma for 3 days. It was later identified that
all affected HCWs were handling Glutaraldehyde (Cidex)
while disinfecting endoscopic instruments.
(a) Describe how would you perform a worksite assessment.
(b) Using the hierarchy of control measures, provide
recommendation in order to minimise the health impact of
Glutaraldehyde (Cidex)
WORKSITE ASSESSMENT
Walk through Survey
5 P’s (People, Premise, Process and Product,
Personal Protective Equipment)
Specific Site
Specific Task
(the pattern of exposure, work procedures)
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Substitution
Replace Glutaraldehyde with a less toxic substance.
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Engineering Controls
Provide local exhaust ventilation such as laboratory hood,
large enough to contain the Glutaraldehyde immersion
system and an equipment washing and rising sink at the
source. The design should include a face velocity at the hood
with the airflow directed toward the back of the hood away
from the operator’s breathing zone. This system will require
an appropriate amount of filtered and tempered replacement
air in order to work properly
Increase general room ventilation. This solution is generally
ineffective in controlling exposure due to short-term tasks
such as equipment cleaning or solution changes that may
generate a high concentration contaminant quickly
Provide buckets and other containers that
are shaped to minimise the surface area
of the liquid.
Modify facility design to limit traffic or
potential exposure to individuals who are
not involved with the disinfection process.
Exposure to Glutaraldehyde solutions in
confined spaces should be avoided
Administrative controls
Reviewing work practices periodically in all areas where
Glutaraldehyde is used in order to prevent
overexposure. Communicate with other areas of the
hospital setting that use Glutaraldehyde such as
surgical department, emergency rooms, intensive care
unit or central sterile supply department
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Training and educating new and current healthcare
workers regarding safe work practices is essential in
reducing chemical exposure. All new and current
healthcare workers should be instructed about the
potential hazards associated with Glutaraldehyde,
proper use of protective clothing, safe work practices,
avoidance of exposure in a confined space and
personal hygiene concerns. This would include
education regarding signs and symptoms associated
with overexposure to Glutaraldehyde
Personal protective equipment
A written procedure detailing the type of clothing
and the proper use of protective clothing should
be provided to healthcare workers involved in
maintenance and disinfecting medical instruments.
Proper gloves wear such as butyl rubber,
polyurethane or Viton could be use
Respirators or face mask are necessary when the
exposure to a chemical exceeds 0.1ppm.
Nevertheless, this should be known not as a
primary control since the availability of
engineering control and substitution of chemical.
Yet, this can still be use in non routine
maintenance or emergencies (NIOSH, 2005).
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Further Information

http://www.worksafe.vic.gov.au

http://www.westcoastdhb.org.nz

http://www.ilo.org

http://www.cdc.gov/niosh

http://toxnet.nlm.nih.gov/