Incorporated Engineer (IEng) Health, Safety and Environmental Responsibility Syllabus

Distinguish between immediate, underlying and root causes of an incident.

Immediate causes are the unsafe acts/conditions directly producing the harm (e.g. missing guard). Underlying causes are management/organisational factors behind them (e.g. no maintenance schedule). Root causes are the fundamental failures in the safety management system that allowed the underlying causes to exist.

What is the difference between a 'near miss' and an 'accident'?

An accident is an unplanned event that results in injury, ill health or damage. A near miss is an unplanned event that had the potential to cause harm but did not — reporting near misses is valuable for proactive prevention.

What is meant by 'designing for safety' (Prevention through Design)?

Addressing occupational and process safety hazards at the design stage of a product, plant or process — where changes are cheapest and most effective — by eliminating or reducing hazards before they reach construction, operation or use, rather than relying on later procedural controls.

What is the principle of 'inherent safety' in process design?

Designing a process so that hazards are eliminated or reduced by the nature of the design itself rather than by added-on protective systems. The four key strategies are: minimise (intensification), substitute, moderate (attenuate), and simplify.

Explain the inherent safety strategy of 'minimisation/intensification'.

Reducing the quantity of hazardous material present in the process (small inventories) so that if a release occurs, the consequences are smaller. Example: using smaller reactors or continuous rather than batch processing to limit hazardous holdup.

Explain the inherent safety strategy of 'moderation/attenuation'.

Using hazardous materials under less hazardous conditions or in a less hazardous form — for example dilution, refrigeration, or operating at lower temperatures and pressures to reduce the energy available to cause harm.

How does inherent safety differ from extrinsic (add-on) safety?

Inherent safety removes or reduces the hazard within the design itself (passive, cannot fail). Extrinsic safety relies on added protective systems, controls and procedures (active/engineered/procedural) that can fail, require maintenance, and must be relied upon to function.

What is HAZOP and what is its purpose?

Hazard and Operability Study — a structured, systematic team-based technique that examines a process design using guidewords (e.g. NO, MORE, LESS, REVERSE) applied to parameters (flow, pressure, temperature) at nodes to identify deviations, their causes, consequences and required safeguards.

List four common guidewords used in a HAZOP study.

NO/NONE (negation), MORE (quantitative increase), LESS (quantitative decrease), AS WELL AS (qualitative increase/addition), PART OF (qualitative decrease), REVERSE (opposite), and OTHER THAN (substitution).

What is a Safe Operating Procedure (SOP)?

A documented step-by-step set of instructions describing how to carry out a task safely. It specifies the correct sequence, hazards, required controls and PPE, ensuring consistency and competence and forming part of a safe system of work.

Name three common hazard identification techniques used in engineering.

HAZID (hazard identification study), HAZOP (hazard and operability study), FMEA (failure modes and effects analysis), checklists, what-if analysis, and job/task safety analysis (JSA).

What is FMEA (Failure Modes and Effects Analysis)?

A systematic bottom-up technique that examines each component or function, identifies its possible failure modes, the effects of each failure, and ranks them — often using a Risk Priority Number — to prioritise design improvements and preventive action.

How is the Risk Priority Number (RPN) calculated in FMEA?

$$\text{RPN} = S \times O \times D$$ where $S$ is severity, $O$ is occurrence (probability), and $D$ is detection (how hard the failure is to detect). Higher RPN values indicate failure modes needing priority attention.

What is 'functional safety'?

The part of overall safety that depends on a system or equipment operating correctly in response to its inputs — i.e. the active protective function works on demand. It is achieved by safety functions implemented in instrumented, electrical/electronic or programmable systems, governed by standards such as IEC 61508/61511.

What is a Safety Instrumented System (SIS)?

An engineered system of sensors, logic solvers and final elements that performs one or more Safety Instrumented Functions to take a process to a safe state when predefined hazardous conditions are detected (e.g. an emergency shutdown system).

Define Safety Integrity Level (SIL).

A discrete level (SIL 1 to SIL 4) specifying the safety integrity requirements (risk reduction) of a safety function. Higher SIL means greater required reliability/risk reduction. SIL 4 provides the highest integrity and SIL 1 the lowest.

How is risk reduction related to Probability of Failure on Demand (PFD) for a low-demand safety function?

$$\text{Risk Reduction Factor} = \frac{1}{\text{PFD}_{avg}}$$ For example, SIL 2 requires $10^{-3} \leq \text{PFD}_{avg} < 10^{-2}$, giving a risk reduction factor between 100 and 1000.

What is the 'duty of care' under the Environmental Protection Act 1990 in relation to waste?

A legal duty on anyone who produces, imports, carries, keeps, treats or disposes of controlled waste to ensure it is stored, transferred only to authorised persons, accompanied by an accurate waste transfer note/description, and prevented from escaping or causing harm or pollution.

Name three key pieces of UK environmental legislation relevant to engineering.

Environmental Protection Act 1990, Environmental Permitting (England and Wales) Regulations 2016, Climate Change Act 2008, Water Resources Act 1991, and the Control of Pollution / Pollution Prevention and Control regimes.

What is the purpose of an environmental permit under the Environmental Permitting Regulations?

To authorise and regulate activities that could pollute air, water or land (e.g. industrial installations, waste operations, discharges) by setting conditions, emission limits and monitoring requirements to protect the environment and human health.

State the 'polluter pays' principle.

The party responsible for producing pollution should bear the costs of managing it to prevent damage to human health or the environment — internalising the environmental cost of an activity into the polluter rather than society.

What is the waste hierarchy and list its order of preference.

A ranking of waste management options from most to least environmentally preferable: 1) Prevention; 2) Preparing for re-use; 3) Recycling; 4) Other recovery (e.g. energy recovery); 5) Disposal (e.g. landfill). It steers decisions toward reducing waste at source.

Define 'sustainable development' (Brundtland definition).

Development that meets the needs of the present without compromising the ability of future generations to meet their own needs. It balances economic, social and environmental considerations.

What are the 'three pillars' (triple bottom line) of sustainability?

Economic (profit/viability), Social (people/equity), and Environmental (planet/protection). Sustainable engineering seeks solutions that are simultaneously economically viable, socially equitable and environmentally sound.

What is meant by 'resource efficiency' in engineering?

Using the Earth's limited resources (materials, energy, water) in a sustainable manner to deliver greater value with less input — minimising waste, maximising recovery/reuse, and reducing environmental impact per unit of output.

What is a life cycle assessment (LCA)?

A systematic 'cradle-to-grave' analysis of the environmental impacts of a product, process or service across all stages — raw material extraction, manufacture, transport, use, and end-of-life disposal/recycling — used to compare options and reduce overall impact.

What does the Climate Change Act 2008 (as amended) require of the UK?

It set a legally binding target to reduce net greenhouse gas emissions, amended in 2019 to require at least a 100% reduction from 1990 levels by 2050 (net zero). It establishes five-yearly carbon budgets and the Committee on Climate Change.

Define 'net zero' carbon emissions.

A state in which the amount of greenhouse gases emitted into the atmosphere is balanced by an equivalent amount removed (through sinks, capture or offsets), giving a net contribution of zero to atmospheric greenhouse gas concentration.

What is 'embodied carbon' in an engineering context?

The total greenhouse gas emissions (often expressed as $\text{kg CO}_2\text{e}$) associated with the materials and construction processes of an asset throughout its life cycle — extraction, manufacture, transport and assembly — as opposed to operational (in-use) carbon.

How does an engineer balance technical, economic and societal needs in a design decision?

By using a structured trade-off / multi-criteria evaluation that weighs technical performance and safety, cost and economic viability (whole-life cost), and societal/environmental impact and stakeholder acceptability — seeking an optimum that satisfies functional requirements while being affordable, safe, ethical and sustainable.