Concept Explainer Sheet: Laser Hazards and Risk Identification

Purpose:

The Concept Explainer Sheet aims to simplify complex theories related to laser hazards, classifications, and risk identification. It uses examples, diagrams, and workplace applications to help learners connect theory to practice in compliance with UK laser safety laws.

Laser Classification Concepts

Definition:

• Lasers are classified according to the hazard they pose to eyes and skin.
• Classification allows selection of control measures and safe handling procedures.

UK Standard Reference:

• BS EN 60825-1:2014 – Safety of Laser Products
• AOR 2010 – Control of Artificial Optical Radiation at Work

Classes of Lasers:

Class	Power & Hazard	Examples	UK Workplace Implications
Class 1	Safe under all conditions of normal use	CD/DVD laser, lowpower barcode scanners	Minimal PPE; ensure correct labeling
Class 1M	Safe unless viewed with optical instruments	Fiber optic communication lasers	Avoid use of magnifying devices
Class 2	Visible lasers ≤1 mW; eye protection usually not required for brief exposure	Laser pointers	Laser pointersUse warning labels; avoid direct eye exposure
Class 2M	Same as Class 2, but hazardous with optical aids	Laser alignment tools	Avoid optical instruments; warning signage
Class 3R	Medium risk; direct eye exposure may be hazardous	Laser scanning devices	Use controlled areas; provide PPE for prolonged exposure
Class 3B	Hazardous if viewed directly; diffuse reflections usually safe	Nd:YAG for tattoo removal	Use controlled access, PPE, interlocks; training mandatory
Class 4	High hazard; direct and scattered beams can cause skin & eye injury; may ignite materials	CO₂ surgical lasers, industrial fiber lasers	Full PPE, controlled rooms, SOPs, fire safety measures, ventilation

Visual Example:

• A diagram illustrating laser beam paths: direct, reflected, and scattered hazards.
• Include arrows showing operator, patient, and bystander exposure points.

Types of Laser Hazards

Direct Beam Hazard

• Definition: Beam strikes eyes or skin directly.
• Example: Class 4 fiber laser cutting metal.
• Control: Interlocks, PPE, beam stops.
• UK Law: HSWA 1974, BS EN 60825-1, PUWER 1998

Reflected Beam Hazard

• Definition: Beam bounces off reflective surfaces.
• Example: Nd:YAG laser hitting a metal tray in a clinic.
• Control: Cover reflective surfaces, use non-reflective instruments.
• UK Law: AOR 2010, BS EN 60825-1

Scattered Beam Hazard

• Definition: Diffuse scattering from tissue or surfaces.
• Example: Laser tattoo removal generating scattered light.
• Control: PPE, controlled area, training.
• UK Law: AOR 2010, COSHH 2002

Biological Effects of Laser Exposure

Type of Risk	Body Part	Mechanism	Example	Control Measure
Photochemical	Eyes,skin	Short-wavelength UV causes chemical reactions	UV laser in lab	UV-rated goggles, shields
Thermal	Skin, eyes	Absorption of energy raises tissue temperature	CO₂ laser for surgery	PPE, controlled beam exposure, SOPs
Mechanical	Eyes	High-intensity pulses cause tissue disruption	Q-switched tattoo removal	Controlled area, PPE, beam alignment

Visual Aid:

• Flow diagram showing laser → tissue interaction → type of damage → control measures

Risk Assessment Principles

Step-by-Step Simplified Approach:

1. Identify Hazards: Direct, reflected, scattered beams; plume; fire risk
2. Determine Likelihood and Severity: Using a simple risk matrix
3. Apply Control Measures: Engineering, administrative, PPE
4. Document Findings: Laser risk assessment form
5. Review and Update: After equipment changes, incidents, or procedure modifications

Example Table:

Hazard	Likelihood	Severity	Risk Rating	Control	Residual Risk
Direct eye exposure	Likely	Severe	High	Interlocks, goggles	Low
Laser plume inhalation	Possible	Moderate	Medium	LEV, masks	Low

UK Workplace Implications

• HSWA 1974: Employer duty of care for all laser operations
• AOR 2010: Protects workers from optical radiation, mandates exposure limits
• BS EN 60825-1 & 60825-14: Defines safe operation and controlled areas
• PUWER 1998: Equipment maintenance and suitability
• COSHH 2002: Controls laser-generated substances like plume
• PPE Regulations 1992: Mandates eye and skin protection

Visual Aid:

• Flowchart linking hazard → legislation → control → verificatio

Workplace Examples

Medical Laser (Tattoo Removal)

• Class 4 Q-switched laser
• Controlled room, PPE, interlocks, plume extraction
• References: HSWA 1974, COSHH 2002, BS EN 60825-14

Industrial Laser (Fiber Cutting)

• Class 4 high-power laser
• Enclosure, PPE, fire-resistant materials
• References: PUWER 1998, Fire Safety Regulations, BS EN 60825-1

Research Lab UV Laser

• Class 3B UV laser
• Beam shields, controlled area, PPE
• References: AOR 2010, HSWA 1974

Learner Task

Instructions:

1. Explain three complex laser concepts in your own words:
   • Example: direct vs reflected beam, photochemical vs thermal risk
   • Include a visual diagram for each concept
2. Select one UK legislation relevant to each concept:
   • Explain how it guides safe operation
3. Develop a mini risk assessment for a laser scenario:
   • Identify hazards, controls, and residual risk
   • Use tables and diagrams
4. Optional: Create a poster-style visual guide summarizing laser hazards and safety measures for your workplace