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Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Laser Safety Seminar
Martin Tschurl
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Outline
– Motivation
– Properties of Laser Radiation
– Dangers
– Legal Framework
– Safety Measures
2
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Motivation
3
Life can be dangerous…
… and laser radiation, too!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Dangers
4
– Lack of Knowledge
– Ignorance
– Fear
– Bad Communication
– Hurry
– (Daily) Routine and Lack of Attention
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
One Example…
5
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Statistics
6
From the RLI Incident Database:
From 2000 to 2010: about 1500 accidents world wide
Laser Type Percentage Person Involved Percentage
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Properties of Laser Radiation I
7
Focusing:
⇒ Spot diameter on retina ~ 10 µm!
⇒ 1300 W/cm2
Focusing:
⇒ Spot diameter on retina ~ 350 µm!
⇒ 6 - 100 W/cm2
Eye‘s lens is focusing the beam!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Properties of Laser Radiation II
8
abso
rbed
radi
atio
n (r
etin
a) /
W/c
m2
Image diameter at retina
Maximal value for retina irradiation (irradiation time: 0.15 s)
daylight
Laser 1 mW (class 2)
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
“Types” of Radiation
9
Direct Beam Reflected Beam Scattered Beam
All Beams are Potentially Harmful!
Light Intensity => Danger
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Wavelengths and Absorption
10
Vis / NIR UV
X-rays / microwave VUV / FIR
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 11
Wavelengths and Damage
Wavelength Damage: Eyes Damage: Skin
Damage of Coronea / Conjunctivits
Sunburn → Cancer Risk
Aging of Skin → Cancer Risk
Photoreactions, Sensitive to Light Cataract (lens)
Damage to Retina
Cataract (lens), Damage to Retina
Photoreactions, Sensitive to Light, Burns
Cataract (lens), Damage to Coronea
Photosensitivity, Burns Burns of Coronea
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Examples
12
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 13
Legal Framework
Download: http://publikationen.dguv.de/dguv/pdf/10002/v-b2.pdf (German version)
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Definitions (German)
Maximal zulässige Bestrahlung (MZB) Maximal Permissible Exposure (MPE)
Threshold value for laser irradiation, which do not cause any negative effects for the irradiated person under normal conditions.
Grenzwert zugänglicher Strahlung (MZB)
Threshold value for the classification of laser radiation. Classification into four classes and subclasses, which depend on the emission wavelength and the output power.
14
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Laser Classes: Class 1
Class 1
Class 1M
A Class 1 laser is safe under all conditions of normal use.
A Class 1M laser is safe for all conditions of use except when passed through magnifying optics such as microscopes and telescopes. Class 1M lasers produce large-diameter beams, or beams that are divergent.
Class 1 and Class 1M: safe Class 1: safe; Class 1M: dangerous
15
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Laser Classes: Class 2
Class 2
Class 2M
A Class 2 laser is considered to be safe, when the blink reflex will limit the exposure to no more than 0.25 seconds (only applicable for visible-light lasers). Class 2 lasers are limited to 1 mW continuous wave.
A Class 2M laser is safe because of the blink reflex if not viewed through optical instruments. As with class 1M, this applies to laser beams with a large diameter or large divergence, for which the amount of light passing through the pupil cannot exceed the limits for class 2.
Class 2 and Class 2M: Safe for short exposure times
Class 2: safe; Class 2M: dangerous for short exposure times
16
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar
Laser Classes: Class 3
Class 3R
Class 3B
A Class 3R laser is classified for an emission in a wavelength range between 302.5 nm and 106, which is dangerous for the eye. The laser power does not exceed five times the MPE of a Class 2 laser or a Class 1 laser for all other wavelengths.
Radiation of a Class 3B laser is dangerous for the eye and in most cases also for the skin.
17
Class 3A Replaced by other classes: Formerly Class 3A lasers emitting in the visible are now classified as Class 2M and for all other emission Class 1M.
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 18
Laser Classes: Class 4
Class 4 Radiation from a Class 4 laser is very dangerous for the eye and dangerous for the skin. By definition, a class 4 laser can burn the skin, or cause devastating and permanent eye damage as a result of direct, diffuse or indirect beam viewing. These lasers may ignite combustible materials, and thus may represent a fire risk.
P > 0.5 W E > 30 mJ
Scientific Lasers usually are Class 4 Lasers!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 19
Laser Classes: Labels
Lasers have to be labelled by the manufacturer!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 20
Safety Regulations: Laser Area
Der Unternehmer hat dafür zu sorgen, dass Laserbereiche von Lasereinrichtungen der Klassen 3 B oder 4 während des Betriebes abgegrenzt und gekennzeichnet sind. Er hat außerdem dafür zu sorgen, dass in geschlossenen Räumen der Betrieb von Lasereinrichtungen der Klasse 4 an den Zugängen zu den Laserbereichen durch Warnleuchten angezeigt wird.
§7 Abs. 2:
Laser areas must not be accessible to unauthorized personal!
The area has to be locked and entrances marked by warning lights!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 21
Safety Regulations: Operation of Lasers
Der Unternehmer hat dafür zu sorgen, dass Versicherte, die Lasereinrichtungen der Klassen 2 bis 4 anwenden oder die sich in Laserbereichen von Lasereinrichtungen der Klassen 3 B oder 4 aufhalten, über das zu beachtende Verhalten unterwiesen worden sind.
§8 Abs. 3:
All people working in the lab have to be instructed for the safe operation with class 4 laser system!
People who have not received an instruction must not be left in the lab unattended!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 22
Safety Hierarchy: TOP
… Technical: Curtains, Interlocks, Housings, …
… Organizational: Instructions for a Safe Operation
… Personal (Individual): Laser Goggles
T
O
P
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 23
Safety Measures: Before You Start…
– Make sure that all of the lab doors are locked!
– Switch on all warning lights!
– Close all curtains! (The radiation must not leave the lab!)
– Tell the other people in the lab that you are going to
switch on a laser!
– Check, if your safety devices (e.g. goggles) are available!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 24
Safety Measures: Working with Lasers I
– Always be aware of the beam path! Check the path by
blocking the laser beam and follow it till it is blocked! Be
aware of all the reflections from optics (lenses,
windows,…)!
– Block all beams, which are not used! E.g. the
fundamental after an SHG process or reflections from
optical components!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 25
Safety Measures: Working with Lasers II
– Do not wear reflective things as watches and other
jewelry that might enter the optical plane!
– Do not bring reflective things (mirrors but also tools) into
the beam path without blocking it beforehand!
– Never put your eyes at the same level as the beam path!
– Always aim for beam paths significantly below eye level!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 26
Safety Measures: Working with Lasers III
– All optical components have to be fixed to the table!
Avoid that the components can easily be moved!
– Reduce the beam path of the laser to a minimum!
– Try to align laser beam with the lowest power possible!
– Wear safety equipment, in particular if you feel
uncomfortable without!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 27
Safety Measures: Protective Eyeware I
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 28
Safety Measures: Protective Eyeware II
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 29
How to Handle Students, Visitors, …
– Best:
Exit to lab to discuss things or, alternatively, switch off
the lasers temporarily.
– If this is not possible:
Do not leave them unattended. Offer them laser
googles. Reduce their presence in the lab to a minimum.
– For longer term visitors/students:
Instruct them!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 30
My Responsibility
– Always check the laser safety and report malfunctions or
problems to the laser safety officer!
– Handle laser beams with care and reduce the risks to a
minimum by the application of safety measures!
– Instruct students or visitors on your own!
– People entering the lab without permission, shall be kick
out immediately!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 31
In case of an emergency:
– Activate the emergency stop button!
– Remove injured people from the area of danger!
– Provide first aid to the injured!
– If it cannot be completely excluded that your eye has been
hit by a laser beam, go and see a physician! (Or encourage
the respective person to do so.)
– Notify our boss or the laser safety officer!
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 32
Check List:
□ Are all doors locked?
□ Are the warning lights switched on?
□ Are all curtains closed?
□ Do my colleagues in the lab know that I am going to switch on the laser?
□ Are all safety devices (paper, goggles, beam dumps) available?
□ Can I be sure about the beam path and reflections?
□ Do I have everything (paper, tools to monitor the beam) to guide the laser beam?
□ Do I have removed my luxuries and watches?
Chemistry Department Chair of Physical Chemistry Catalysis Research Center
Laser Safety Seminar 33
Everybody is Responsible for His Own Safety and the Safety in His Lab!
Routine Work and Lack of Attention are the Major Enemies!
…always remember: You can get a third set of teeth, but no second set of eyes!
If You are not Sure How to Handle Things, Ask your Laser Safety Officer!
1. 2. 3.
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