Laser Safety Flashcards
What hazards are there from lasers? (4 marks)
Ocular hazard (permanent eye damage), skin damage, fire risk, dazzling/disorientation e.g. pilots.
What laser classifications are there? (5 marks)
Class 1 = enclosed or no danger to vision (M means safe so long as magnification is not used), e.g. CD player.
Class 2 = No hazard to skin, and no real eye hazard (blink reflex should be enough) e.g. laser pens.
Class 3 = (a) not a skin hazard and blink reflex should protect eye, damage may occur from prolonged viewing (b) not a skin hazard but may cause eye damage, goggles should be worn.
Class 4 = hazard to eyes and skin, also a fire risk.
What is meant by the term MPE? (2 marks)
It is the maximal permissible exposure, given in J/m^2 or W/m^2, and is the threshold for which damage may be done to the eye or skin. It varies for tissue, wavelength, power etc.
What is the NOHD and what is the equation for it? (2 marks)
Nominal Occular Hazard Distance = distance at which MPE might be exceeded taking into account potential viewing time, blink reflex etc.
NOHD = 2/theta [P/(pi*MPE]^0.5
Theta is the divergence or AA in radians.
What measures are required for lasers of class 3 and up? (4 marks)
- Local rules
- Warning signs
- Risk assessment
- Designation of individuals such as a LPA, LPS, CLE
- Goggles suitable for laser.
What is the role of the LPA, CLE and LPS? (9 marks)
Laser protection advisor: QA and audits, advice.
Clinical Laser Expert: lead clinician responsible for training operators in safe use of the laser.
Laser protection supervisor: responsible for day-to-day safety of the area and ensuring the local rules there and being followed, risk assessment. Maintains list of authorised users.
