What is the difference between COSHH and REACH?

COSHH (Control of Substances Hazardous to Health) is UK legislation that focuses on protecting workers from hazardous substances in the workplace. REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) is an EU regulation that governs the manufacture, import, and use of chemicals to protect human health and the environment. While COSHH is about controlling exposure at work, REACH ensures that chemicals are safe before they enter the market. In practice, both work together: REACH provides hazard information (e.g., via safety data sheets), and COSHH uses that info to manage risks.

Do I need to do a COSHH assessment for every single substance?

Not necessarily. You should focus on substances that are hazardous to health. For low-risk substances (e.g., water-based glue with no hazardous ingredients), a simple note may suffice. However, if you use many similar substances (e.g., different brands of degreaser), you can group them into one assessment if the hazards and controls are the same. The key is to prioritise substances with high risk or high exposure potential. Always document your reasoning.

What are the most common hazardous substances in engineering?

Common ones include metalworking fluids (can cause dermatitis and respiratory issues), welding fumes (containing manganese and chromium, linked to lung damage), solvents (e.g., acetone, toluene – cause dizziness and skin irritation), cutting oils, paints and coatings, and dusts from grinding or sanding (e.g., silica, wood dust). Also, cleaning agents and adhesives are frequently used. Always check safety data sheets for specific hazards.

How often should COSHH assessments be reviewed?

COSHH assessments should be reviewed regularly, at least every 2-3 years, or whenever there is a significant change in the workplace (e.g., new substance, new process, change in staff, or after an incident). If a health surveillance programme reveals issues, that also triggers a review. The key is to keep them up to date and ensure controls remain effective.

What is health surveillance and when is it required?

Health surveillance is a system of ongoing health checks to detect early signs of work-related ill health. It is required under COSHH when exposure to a hazardous substance could cause a specific disease (e.g., dermatitis from metalworking fluids, asthma from isocyanates, or lung damage from silica). It involves things like skin checks, lung function tests, and questionnaires. The purpose is to identify problems early so you can improve controls and protect workers.

Can I use a generic COSHH assessment from the internet?

You can use a generic assessment as a starting point, but it must be tailored to your specific workplace. Generic assessments don't account for your exact substances, quantities, processes, and control measures. For example, a generic assessment for 'solvent' might not consider that you use it in a small, unventilated room. Always review and adapt it to your actual conditions, and document your site-specific findings.

Principles of the Control of Substances Hazardous to Health

CHARTERED INSTITUTE OF ENVIRONMENTAL HEALTH

vocational

This element covers the fundamental principles of the Control of Substances Hazardous to Health (COSHH) Regulations, including legal responsibilities, risk assessment processes, and control measures. Learners will explore how to identify hazardous substances, evaluate risks, and implement appropriate precautions to prevent or minimize exposure in the workplace. Understanding these principles is essential for ensuring compliance and protecting health.

Learning Outcomes

Assessment Guidance

Key Skills

Key Terms

Assessment Criteria

Assessment criteria

CIEH Level 2 Award in Principles of COSHH (QCF)

Topic Overview

The CIEH Level 2 Award in Principles of COSHH (Control of Substances Hazardous to Health) is a foundational qualification for anyone working in manufacturing and engineering. It covers the legal framework of COSHH Regulations 2002, which require employers to control exposure to hazardous substances to protect workers' health. In manufacturing and engineering, common hazards include metalworking fluids, welding fumes, solvents, and dusts. Understanding COSHH is essential for reducing risks like dermatitis, asthma, and occupational cancer.

This course teaches you to identify hazardous substances, interpret safety data sheets, and apply control measures such as ventilation, personal protective equipment (PPE), and safe handling procedures. It also covers health surveillance and emergency planning. Mastering COSHH principles not only ensures legal compliance but also fosters a safety culture that prevents accidents and long-term ill health. For engineering students, this knowledge is directly applicable to workshop environments, chemical storage, and maintenance tasks.

The qualification fits into broader health and safety training, often complementing IOSH Managing Safely or NEBOSH General Certificate. It is a prerequisite for many engineering roles and demonstrates due diligence to employers. By the end, you should be able to conduct a simple COSHH assessment and contribute to risk reduction in your workplace.

Key Concepts

Core ideas you must understand for this topic

→Hazard vs. Risk: A hazard is something with potential to cause harm (e.g., a toxic chemical), while risk is the likelihood and severity of harm occurring. COSHH focuses on controlling risks, not just identifying hazards.
→The 8-Step COSHH Assessment Process: 1) Identify hazards, 2) Decide who might be harmed and how, 3) Evaluate risks and decide on precautions, 4) Record findings, 5) Review and update, 6) Provide information and training, 7) Implement control measures, 8) Monitor exposure and health.
→Workplace Exposure Limits (WELs): Legal limits on airborne concentrations of hazardous substances, expressed as long-term (8-hour TWA) or short-term (15-minute STEL) exposure limits. Exceeding these requires immediate action.
→Hierarchy of Control: Elimination (remove hazard), substitution (replace with safer substance), engineering controls (e.g., local exhaust ventilation), administrative controls (e.g., safe systems of work), and PPE (last resort).
→Safety Data Sheets (SDS): 16-section documents from suppliers providing critical info on hazards, handling, storage, and emergency measures. Sections 2 (hazards), 3 (composition), 8 (exposure controls), and 15 (regulatory info) are key for COSHH assessments.

Learning Objectives

What you need to know and understand

Understand the law relating to hazardous substances in the workplace, Understand how risk assessments contribute to the safe use of hazardous substances in the workplace, Understand the precautions and procedures necessary to ensure the risks associated with hazardous substances are properly controlled

Assessment Criteria

Key criteria assessors look for in your portfolio

Award credit for accurately describing the legal duties of employers and employees under COSHH, including risk assessment, control, and training requirements.
Award credit for demonstrating a practical understanding of the risk assessment process, such as identifying hazards, evaluating risks, and recording significant findings.
Award credit for explaining the hierarchy of controls (elimination, substitution, engineering controls, administrative controls, PPE) and giving appropriate examples for specific hazards.

Assessment Guidance

Guidance for achieving higher grades

💡When answering questions, always structure your response around the COSHH framework: identify substance, assess risk, decide on controls, implement, and review.
💡Use real-world examples from manufacturing and engineering settings where possible to demonstrate application of principles.
💡Pay close attention to scenario-based questions: identify the specific hazardous substance, its route of entry, and the most effective control measure from the hierarchy.
💡Always link control measures to the hierarchy of control in your answers. For example, when asked how to reduce risk from solvent vapours, start with elimination (use water-based cleaner), then engineering (LEV), then PPE (respirator). This shows deeper understanding.
💡Memorise the 8-step assessment process and be ready to apply it to a scenario. Examiners love questions like 'Describe how you would carry out a COSHH assessment for a new chemical in a workshop.' Use the steps as a checklist.
💡Know the difference between acute and chronic health effects. Acute effects (e.g., dizziness from solvent inhalation) occur quickly; chronic effects (e.g., lung damage from long-term welding fume exposure) develop over time. Mention both in answers to show breadth.

Common Mistakes

Common errors to avoid in your coursework

Confusing the terms 'hazard' and 'risk'—a hazardous substance is the potential to cause harm, while risk is the likelihood of harm occurring.
Overlooking less obvious routes of exposure, such as ingestion or absorption through skin, focusing only on inhalation.
Assuming that personal protective equipment (PPE) is always the first line of defense rather than understanding the hierarchy of controls.
Misconception: 'If a substance has a safety data sheet, it's automatically covered by COSHH.' Correction: COSHH applies to any hazardous substance, including those without an SDS (e.g., dusts from machining). An SDS is a tool, not a requirement for COSHH applicability.
Misconception: 'PPE is the best control measure.' Correction: PPE is the least effective control in the hierarchy. It only protects the wearer and can fail. Engineering controls like ventilation are more reliable and should be prioritised.
Misconception: 'COSHH assessments are only for chemicals.' Correction: COSHH covers all hazardous substances, including biological agents (e.g., bacteria in metalworking fluids), dusts (e.g., wood dust), and fumes (e.g., welding).

Frequently Asked Questions

Common questions students ask about this topic

Before You Start

Prior knowledge that will help with this topic

•Basic understanding of health and safety principles (e.g., from a general induction or IOSH Working Safely).
•Familiarity with common workplace hazards in manufacturing or engineering (e.g., chemicals, dusts, fumes).
•No formal prerequisites, but practical experience in a workshop or factory setting helps contextualise the learning.

Key Terminology

Essential terms to know

Understand the law relating to hazardous substances in the workplace, Understand how risk assessments contribute to the safe use of hazardous substances in the workplace, Understand the precautions and procedures necessary to ensure the risks associated with hazardous substances are properly controlled

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Principles of the Control of Substances Hazardous to Health

Assessment criteria

Topic Overview

Key Concepts

Learning Objectives

Assessment Criteria

Assessment Guidance

Common Mistakes

Frequently Asked Questions

Before You Start

Key Terminology

Ready to learn?

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Topic Synopsis

Key Concepts & Core Principles

Exam Tips & Revision Strategies

Common Misconceptions & Mistakes to Avoid

Examiner Marking Points

Principles of the Control of Substances Hazardous to Health

Assessment criteria

Topic Overview

Key Concepts

Learning Objectives

Assessment Criteria

Assessment Guidance

Common Mistakes

Frequently Asked Questions

What is the difference between COSHH and REACH?

Do I need to do a COSHH assessment for every single substance?

What are the most common hazardous substances in engineering?

How often should COSHH assessments be reviewed?

What is health surveillance and when is it required?

Can I use a generic COSHH assessment from the internet?

Before You Start

Key Terminology

Ready to learn?

Related Topics in CHARTERED INSTITUTE OF ENVIRONMENTAL HEALTH vocational Manufacturing & Engineering

Fire Risk Assessment and Control

Risk Assessment – Principles and Practice

Principles of HACCP based food safety systems

The principles of food safety for manufacturing