Thermal Hazard
Intense heat
Longer wavelengths (towards red) make thermal hazard more likely
Thermal hazard depends on power and wavelength
Water containing tissues are more susceptible biological material to thermal hazard because water turns to steam and that fractures cells. Damage to cells will occur in nS, so very fast indeed (faster than the scanning of a laser beam)
Burns have 3 severities:
- Superficial
- Partial
- Full thickness
Photochemical Hazard
Eye hazards
Visible 400 – 1400nm
The eye lens condenses light down so it becomes super concentrated when it hits the back of the eye. It can be x10,000 times greater energy at the back than when it it passed through the front of the eye (cornea)
Blue + green are most hazardous
Non-visible
UV < 400nm, IR > 1400nM
Cornea (front of eye) can also be damaged by IR and UV wavelengths
Once a rod in the eye is burnt it doesn’t repair, you get left with a black spot in your visual field. Over time the brain will adapt and eventually mask it.
Skin Hazard
Can cause burns, scarring, discolouration. If it penetrates through the skin layers it hits the subcutus which is darker so absorbs more of the energy, so burns more.
Severity depends on wavelength, power and duration
Mechanical Hazard
Hazard is more common with high power pulse lasers.
The laser beam can induce shockwaves in what it hits.
Non Biological Hazards
Electrical hazards
Occupational hazards (rigging it, manual handling, working at height, access machinery, other contractors)
Fire hazards
Intense heat and concentrated energy. Ignition source for flammables.
Charing of materials also a hazard, causes fumes that may be hazardous.
Flash point of a material is when it catches fire.
Chemical Hazards
Chemicals, solvents, adhesives, and dyes used to manufacture equipment that can be released due to laser.
Inhalation, skin contact, ingestion.
Haze, smoke machines
Adverse health effects
Environmental Hazards
Disposal of dangerous materials (very small quantities in lasers, but diodes have some funky materials used to create the beam!
Throwing away smoke fluid in drains
