Health, Safety & Environmental (HSE) Management In Engineering Practice
COMPONENTS OF HSE MANAGEMENT
Health, Safety and Environmental management should be part of the engineering profession in a country for the purpose of
o duty of care
o economic reasons and
o legal reasons.
HSE management should therefore consider five broad phases:
* Design and implementation
* Installation and commissioning
* Operation and maintenance
* Changes after commissioning.
* Compliance with the standards requires four essential elements:
* Identification of safety functions required for the safe shutdown
* Assignment of a safety integrity level (SIL) for each safety function
* Use of the safety lifecycle for the engineering design and
* Verification of the SIL achieved for each safety function.
3.0 ENGINEERING CODE OF PRACTICE
The engineering code of practice takes into consideration the following:
* Public safety: Giving priority to the safety and well-being of the community and having regard to this principle in assessing obligations to the clients, employers and colleagues.
* Risk Management: Taking reasonable steps to minimize the risk of loss of lives, injuries or suffering.
* Workplace and construction site: Minimizing potential dangers involved in the construction and manufacture of engineering products and processes.
* Public/Community well-being
* Conflicts of interest
The privilege of practicing engineering is entrusted to those qualified and who have the responsibility for applying engineering skills, scientific knowledge and ingenuity for the advancement of human welfare and quality of life. Fundamental principles of conduct of engineers include truth, honesty and trustworthiness in their service to the society, honourable and ethical practice showing fairness, courtesy and good faith towards clients, colleagues and others. Engineers take societal, cultural, economic, environmental and safety aspects into consideration and strive for the efficient use of the world’s resources to meet long term human needs.
4.0 SAFE ENGINEERING DESIGNS
Safety is a concern in virtually all engineering design processes. Engineers should understand safety in the context of engineering design and what it means to say that a design is safe against human injuries.
Current design methods prioritize economic considerations over environmental ones. In some cases, economic considerations also serve environmental goals. For instance, the minimization of materials used in a structure means resources are saved. If they are saved at the expense of the length of the operating life of a product, then, economic considerations conflict with environmental interests which demand that products be made as durable as possible because of the need to minimize resource usage and waste generation in the long term.
Safety is the antonym of risk. So, a design is safe to the extent that it reduces risk. Safe design aims at minimizing risk in the standard sense of this term.
A safe design is the combination of all those procedures and principles that are used by engineers to make designed objects safe against accidents leading to human death or injuries, long term health effects, damage to the environment or malfunctioning in general.
Several design strategies used to achieve safety in operations of potentially dangerous technology are:
* inherently safe design
* safety factors
* negative feedback (self-shutdown) and
* multiple independent safety barriers.
Probabilistic Risk Assessment (PRA) is the most common method of assessing safety but safe designs are used to reduce risks in the standard (probabilistic) sense but is inadequate. Safe design strategies are used to reduce estimated probabilities of injuries or reducing uncertainties not only risks. They are used to cope with hazards and eventualities that cannot be assigned meaningful probabilities.
5.0 DESIGN PRINCIPLES IN ENGINEERING
There are four (4) main design principles in Engineering practice.
(a) Inherently safe design:
This minimizes the inherent dangers in the process as far as possible. Potential hazards are excluded rather than enclosed or coped with. For instance, dangerous substances are replaced by less dangerous ones and fire proof materials are used rather than inflammable ones.
(b) Safety Factors
Construction should be strong enough to resist load and disturbances exceeding those that are intended. A common way to obtain such safety reserves is to employ explicitly chosen numerical safety factors are employed. If a safety factor of two (2) is employed when building a bridge, then the bridge is calculated to resist twice the maximal load to which it will be exposed to in practice.
(c) Negative feedback mechanisms
This is introduced to achieve a self-shutdown in case of device failure or when the operator looses control. Examples are safety valves that let out steam when the pressure is too high in a steam boiler and the dead man’s hole that stops the train when the driver falls asleep. One of the most important safety measures in the nuclear industry is to ensure that reactors close down automatically in critical situations.
(d) Multiple Independent Safety Barriers
Safety barriers are arranged in chains, so that each barrier is independent of its predecessors (if the first fails, the second is still intact). The first barriers prevent accidents; the second barriers limit the consequences of an accident and rescue services as the last resort.