Lab Safety

General Rules of Conduct

never stay alone in the laboratory ¹⁾²⁾
carefully read the instruction manuals of the instruments used
before leaving the laboratory, always ensure that all instruments are in safe condition (check-list)
use helmets, gloves, and protective goggles when necessary
record all operations performed in the appropriate logbooks
mark hazardous areas with the red-and-white chain or tape
if it is necessary to access the laboratory outside the department's opening hours, two people must be present and the Supervisor must be informed in advance
do not tamper with or remove safety devices
keep clear access to the black doors that serve as the laboratory's emergency exits (do not block corridors or doors, …)
keep clear access to laboratory doors
do not remove mezzanine railings
wear suitable shoes (for example closed and without heels) to prevent accidents on stairs and protect against impacts or small accidental spills of cryogenic liquids

Supervisor (document in italian) for research and teaching activities: Marco Faverzani (tel. 2225)
In the absence of the supervisor, the most experienced person is responsible for laboratory activities: normally Elena Ferri (tel. 2354)
Head of Prevention and Protection Service (RSPP), University of Milano-Bicocca: Francesca Peltrera (tel. 6109) (email [servizio.prevenzione@unimib.it](mailto:servizio.prevenzione@unimib.it)]
Head of Prevention and Protection Service (RSPP) (INFN Milano-Bicocca Section): Giuseppe Bestiani (tel. 2330)
Qualified Expert, Department of Physics: Stefano Giunti (external); for issues related to radioprotection, contact Marco Faverzani
Cryogenic liquids manager: Roberto Gaigher (tel. 2312)
Personnel authorized to use lifting equipment: Giancarlo Ceruti, Angelo Nucciotti

leave the laboratory immediately
immediately report the alarm to the supervisor
do not disable the alarm
in any case, do not re-enter the laboratory until the external display shows that oxygen levels have returned to normal (>20%) and until the visual alarm outside the lab has been turned off
do not tamper with safety systems:
- do not bypass the solenoid valve that intercepts the gaseous nitrogen line
- do not damage oxygen sensor capsules by exposing them to solvent vapors or gas flows
immediately report any anomalies in the oxygen sensors to the supervisor

in case of blackout, the UPS (Uninterruptible Power Supply) system, thanks to its battery backup, will ensure the operation of cryostats, oxygen sensors, certain lights, and other equipment connected to panels with a red label until the batteries are depleted (actual duration depends on total load)
computers connected to the UPS will automatically shut down after a few minutes
in case of blackout, the air conditioning and ventilation system ³⁾ stops immediately
once UPS backup ends, the oxygen monitoring system will no longer be active
in case of a prolonged blackout, if necessary, use the UPS time to safely secure cryogenic systems and leave the laboratory; otherwise, leave immediately
in any case, once UPS backup ends, leave the laboratory immediately

Liquids used in the laboratory
- Liquid helium (T=4K)
- Liquid nitrogen (T=77K)
risk of cold burn
- always use cryogenic gloves
- wear protective goggles
- do not touch cold parts with bare hands (especially metals)
risk of asphyxiation ⁵⁾
- pay attention to oxygen sensors: in case of alarm, leave the laboratory immediately and report the risk
- keep liquid helium containers connected to the copper recovery line
risk of explosion ⁶⁾
- check the opening of safety valves
- check the closure of vent valves
- always check pressure difference before opening a valve
keep all containers vertical
do not use dewars to pour liquid
always close containers with proper lids
beware of ice plugs formation (possible high pressure)
in doubt, call the responsible person
Safety chapter extracted from "Handbook of Cryogenic Engineering", J. Weisand
Inventory of cryogenic liquids and evaluation of evaporation impact
Liquid Nitrogen Safety Data Sheet (document in italian)
Liquid Helium Safety Data Sheet (document in italian)

gases distributed in the laboratory: compressed air, nitrogen, and helium
high pressures may also occur in dilution refrigerator circuits
always close both valves at the take-off points
before opening valves, set the regulators to minimum
keep regulators below 500 mbar
use suitable hoses for gas withdrawal and always check their condition before use
do not tamper with safety valves
always check pressure difference before opening a valve

overhead crane, electric hoist, forklift, and pallet truck may only be used with support from authorized personnel
when working with suspended loads, wear protective helmets

it is strictly forbidden to tamper with electrical systems
access to electrical panels is allowed only for maintenance staff
it is strictly forbidden to tamper with electrical connections of instrumentation
do not leave computers or control panels open
electrical connections of equipment must only be made by electricians
do not overload power strips; always check the maximum rating
do not connect multiple power strips in series
do not leave power strips on the floor, especially near areas where cryogenic liquids are used

New Safety Procedures for UNIMIB Research Laboratories (10/02/2023) Forms and procedures (website in italian)
General operating procedures provided by the Prevention and Protection Service
Complete documentation procedure_applicabili_lab_criostati.zip moduli.zip
here you can find specific procedures for all operations involving various risks
Each laboratory user must review
- all general Operating Procedures listed above
- the specific rules, instructions, and procedures for the Cryostats laboratory available on this page or through links
Each laboratory user must sign Form 052 (Acknowledgment of receipt of safety and health information)
Each laboratory user must print and sign this page

—

\ \

The undersigned ……………………………………………………………….

declares to have read and understood the information contained in this page, in the attached documents, and in the linked pages.

Date ……………………………………….

Signature ………………………………………

¹⁾

all equipment can be remotely supervised

²⁾

Under no circumstances may students remain without supervision

³⁾

⁴⁾

students, undergraduates, PhD students, and research fellows are considered full workers

⁵⁾ , ⁶⁾

the volume change from liquid to gas is about 700 times: 1 liter becomes 0.7 m³