2015/01/19occupational safety annual briefing 2015 1 occupational safety in our laboratories michael...

2015/01/19 Occupational safety annual briefing 2015

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Occupational safety in our Laboratories

Michael Schulz

With kind assistance of safety specialist M. Wied

Max-Planck-Institut für Festkörperforschung, Stuttgart


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Overview

Transport and storage of cryogens and gases

Safety rules for cryogenic usageSafe handling of LASER devicesHandling and storage of chemicalsOccupational safety notes


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• Man and cryogen or gas always travel separately– the cargo-elevator for cans and gas cylinders– the staircase or the common elevator for you

• Why that?– In case the elevator gets stuck and He or N2 is leaking, you

might suffocate before the service technicians get you out• Therefore block the cargo elevator with the priority key!

– Elevator works only with registered smart cards (see Mr. Winzenz 3M29.1)

General transportation rules for cryogens and gases


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• Priority keys for the cargo elevator:– 6 D 10 inside the Dosimeter safe– 7 B 11 at the doorframe on the right hand side

Transporting LHe- and LN2- cans

• To avoid pressure build-up, always connect He-cans to the return line immediately after transport

• Only unpressurized transport for LN2-cans


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Transporting gas cylinders

• Only without pressure regulating valves

• Safety cap fixed on top

• Use chain in cargo elevator


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Storage of gas cylinders• Use chains to prevent gas bottles from

toppling over

• Close pressure regulating valve, but leave the main valve open

Main valve

Pressure regulating valve


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• Should be stored inside gas cylinder cabinet

• Try to reduce amount of gas cylinders to the minimum


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Safety precautions for refilling cryogens

• Wear protective equipment

• Cover skin

• Wear close-toed shoes


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• Before you start check the tubes for cracks, they might break during refilling procedure

• Frozen tubes are brittle, so keep your distance and beware of flying debris and cold exhaust


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• Ambient medium condenses on the surface of Non-insulated ducts, transporting cold He-gas or liquid He.

• At first, humidity freezes as ice on the surface of the ducts.

• Hereafter the most dangerous state, the selective condensation of oxygen at -183°C (90 K), begins. Ice is now “washed off“ off the ducts.

• Oxygen is dripping from the duct. Due to increased concentration of oxygen at ground level there is a fire hazard!

Refilling liquid He and N2


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• To avoid selective condensation choose slow filling rate boil off reduced

• Keep electric equipment out of range of the higher oxygen concentration


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• Prior to refilling your system check tubes and valves

• Always wear protective clothing

• Choose slower filling rates

• Avoid refilling when you‘re alone

• Stop refilling LN2 and LHe immediately when exhaust turns liquid

Summary

Our magnet systems


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16 Tesla Oxford

9 Tesla PPMS and 9 Tesla Oxford

7 Tesla VSM-Squid


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Cross section of cryostat

4x LIFTING LUGSRUPTURE DISC

LIQUID NITROGENFILL PORTS

EVACUATIONVALVE

o 28

.00

LIQUID HELIUM

LIQUID NITROGEN

ACTIVATEDCHARCOAL

NITROGENJACKET

LIQUID NITROGENFILL PORTS

SUPER-INSULATION

17.1

2

6.62

31.0

29.

75

40.7

7+

25

0 0

00

-

6.52 ID

24.00

45.5

01

25+ -


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Magnet-quenchA Laboratory has approx. 75 m³ capacity of breathable air,

stored energy inside magnet at maximum field: 100 KJ

In case of a quench this energy is yielded to the He,causing an immediate boil off of up to 40 l He.

The produced amount of gas is approx. 30 m³ He-gas.

Thus the oxygen concentration of the ambient air is reduced to

approx. 60 %.That means 12.6 % instead of 21 %.

Leave lab immediately ! lack of oxygen !


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Composition of atmospheric air

H2 He Ne Ar Kr Xe N2 O2

Volumetric content [%]

0,9378,0

820,9

4

Volumetric content [ppm]

0,5 5,2418,1

81,14

0,087

Boiling point[K]

20,4 4,2 27,1 87,3119,

8165 77,3 90,3


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Consequences of oxygen deficiency

11 – 17 Vol% O2: unrecognized physical and mentalloss of efficiency

8 – 11 Vol% O2: after several minutes without warning loss of consciousness

6 – 8 Vol% O2: unconsciousness in a few minutes

< 6 Vol% O2: instant unconsciousness, after 4 minutes persistant cerebral

damages, after 8 minutes death

Spectrum of LASER devices


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Wavelength range

Effect on the eyes Effect on the skin

100-315 nm Inflammation of the cornea sunburns, acceleratedageing, skin cancer

315-400 nm Lens opacification

Darkening of pigment, burns400-700 nm Retinal injury

3000 nm- 1mm Corneal burn

Lens opacification, retinal injury

700-1400 nm

1400-3000 nm Lens opacification, corneal burn

Burns

CO2-Laser

Nd-YAG-Laser

UV

VIS

IR

Excimer-Laser

High-performance diode Laser

Increased pigmentation, skin cancer

He-Ne-Laser

Effects of LASER-Beams


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Classification of Laser-devices

Laser

class

possible

threat

typical power P

typical application

1 Safe under reasonably predictable conditions

P < 0,4 µW DVD-Player scanning cash register

1MHazardous to the eye only when passed through magnifying optics such as microscopes and telescopes

P < 0,4 µW

with beam-

diameter > 7 mm

measuring Laser

with widening (data transfer)

2Intentional suppression of the blink reflex > 0,25s could lead to eye injury

P < 1 mWLaserpointer, Laser mechanic‘s level

acc. to BGV B2 and BGI 832


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Laser

class

possible

threat

typical power P

typical application

2MHazardous only if viewed through optical instruments

P < 1 mW with beam-

diameter > 7 mm

Laser projector

3 AHazardous only if viewed through optical instruments

P < 5 mW with beam-

diameter > 7 mm


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Laser

class

possible

threat

typical power P

typical application

3 RRadiation exceeds the MPE values, safety glasses are recommended

P < 5 mWtargeting laser (mil.)

3 Bhazardous to the eyes and skin, safety glasses are obligatory

P < 500 mW beauty treatment

4hazardous to the eyes and skin, safety glasses and PSE are obligatory

P > 500 mW

High performance

research Laser, medical applications, cutting and welding


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Labeling of Laser-devices

LASER RADIATIONDO NOT STARE INTO BEAMCLASS 2 LASER PRODUCTAcc. to EN 60825-1:2001P 1 mW; = 632,8 nm

Warning sign

Additional label withPerformance parameters

Laser class 1 and 1M:

Need not to be labeled explicitly if performance parameters are included in the manual by the manufacturer.


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Shield the laserbeam

Decrease laserpower to the effectively needed energy level

Fence off laser work area

Avoid sphere of influence of the laserbeam

Use personal safety equipment

Protection from laser irradiation


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Eye protection, labeling


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• Never forget to wear your personal protective equipment / check internal plant instructions

• Use fume hoods for working with solvents and other chemicals

• To dispose ask Mr. Konrad from the supply store

• For storage there is an hazmat cabinet in 6D12

Basics for handling chemicals


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Personal Protective Equipment

The supply store can provide you with tables, equipment and further advice.

For Lab-coats see Ms. Bühler next to the supply store.

Handling aggressive chemicals

Such as Hydrofluoric acid (HF) for etching samples:•Listen to instructions given by trained personnel•Be extremely careful and double check your PPE!•Your PPE might be contaminated don‘t touch it after removal!


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HF burn, not evident until a day after (wikipedia)


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Occupational safety notes

• Internal plant instructions for handling equipment and chemicals

• System instruction

• Guidelines (Institutssicherheitsordnung)


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Internal plant instructions

• In every Lab near exit• Marked with bright

green arrow• Contain important

instructions


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System instruction


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GUIDELINES AND RULES OF THE MAX PLANCK SOCIETYON A RESPONSIBLE APPROACH TO FREEDOM OF RESEARCH

AND RESEARCH RISKS

* The following “Max Planck Society Guidelines and Rules on a ResponsibleApproach to Freedom of Research and Research Risks” were drawn up by the“Security and Defense Research” Working Group, with the support of the EthicsCouncil of the Max Planck Society, at the request of the Scientific Councilof the Max Planck Society and were unanimously approved by both bodies. TheScientific Council of the Max Planck Society acknowledged the rules with approvalat its meeting of February 18, 2010 and decided to recommend approvalof the rules to the Senate of the Max Planck Society which also approved it inits meeting of March 19, 2010.


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In case of further questions

Feel free to see me in my office:

6 A 9


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Thank you for your attention!

2015/01/19occupational safety annual briefing 2015 1 occupational safety in our laboratories michael...

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