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
BSc (Health and Safety), Curtin University, Perth Australia
A situation that poses a level of threat to life, health, property or environment
The chance of something happening that will have an impact on life, health, property or environment
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).
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.
"Dosisfacitvenenum" - 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)
The dose of a hazardous substance is generally expressed with the following equation:
Dose = concentration (level) x durationof exposure.
This is a fundamental principle on which occupational exposure limits (OELs) are based
Refers to its capacity to injure if it reaches a susceptible site on the body. Whether ill-effects will occur depends on:
Substances which can be inhaled, or are respirable, include gases, vapours and aerosols, may be defined as follows:
A document containing important information about a hazardous chemical (which may be hazardous substance and/or dangerous goods) and must state:
International Version published by the WHO and European Union
A large range of vapours and gases, dusts, fumes can enter the respiratory tract through inhalation
The protective properties of the skin can be reduced by exposure to chemicals such as degreasers, detergents, and solvents
complaints, illness statistics, biological or
radiological signs before symptoms occur)
(MSDS, material inputs, the process, the
pattern of exposure, work procedures)
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
Chemical handling on and risk evaluationGlutaraldehyde (Cidex) for disinfecting endoscopy and operating theatre instruments
5 steps of hierarchy of control measures
-Detrimental effect on human body
-Demand of the product
-Replace with a less hazardous substance
-Fume Cupboard (Grading for different types of chemical handling/performance)
-Ventilated room with back vent
-Education and Training
-Standard Safety Procedure (Chemical Handling)
-Regular medical checkup
Different types of chemical have different use on each equipment
-Safety Apron/Safety Suit
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 and risk evaluation
Walk through Survey
5 P’s (People, Premise, Process and Product, Personal Protective Equipment)
(the pattern of exposure, work procedures)
Replace Glutaraldehyde with a less toxic substance.
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
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
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
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).