Generic Risk Assessment Form

Department School of
Psychology
Building
CUBRIC
Room No
Name of
Assessor
Date of Original
Assessment
30 April
2007
ID No
[optional*]
Dr S K Rushton
MRI Suite
You may wish to use an ID No. if you want to have a unique identifier of the risk assessments within your
department
Brief Description of Procedure/Activity and its Location: [Guidance note 2]
Perception of object movement during simulated self-movement in normal healthy research
volunteers in the MRI system at CUBRIC
The magnetic resonance imaging (MRI) system is housed within the MRI suite of the CUBRIC
building.
The system can be used for research scanning of tissue structure and function in human
participants. This risk assessment covers the scanning of normal healthy volunteers.
A minimum of one trained CUBRIC staff member and one additional Approved User is needed to
be present for each scan. For the initial core-staff, scan training will be provided by the MRI
supplier, General Electric. After this initial period, training will be provided by CUBRIC staff.
Note that this document covers MRI scanning by Cardiff University staff only.
CUBRIC is a new facility and the risk calculations detailed on the next two pages are made
assuming the control measures detailed in the tables on Page 1 and 2 are properly implemented.
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
1
Hazards Involved: [Guidance note 3-5]
Substance/Item of
equipment/procedure or
physical location
Associated hazards
Static magnetic field produced
by the superconducting
magnet of the 3T MRI
machine
1. Projectile action of loose
objects
containing
ferromagnetic
metals
(such as iron, steel and
nickel) brought within the
vicinity of the magnet.
2.Electrically, mechanically
or magnetically activated
implants (such as cardiac
pacemakers) may
be subject to electromagnetic
interference,
heating and a mechanical
force in or close to the MR
system
3.Ferro-magnetic
prostheses and implants
may be displaced when
introduced to the magnetic
field. Metallic implants may
undergo heating during a
scan as a result of RF
exposure.
4.Metallic foreign bodies
from working with metal or
shrapnel wounds
Existing Control Measures
Operators and researchers are instructed to
follow the CUBRIC Rules and Procedures
Document to ensure the safety of themselves,
colleagues and participants. Only subjects who
have been screened may enter the controlled
area. This includes all accessible areas where
the magnetic field exceeds 0.5mT(5 gauss)
Severity
5
Likelihood
1
Risk
5
All equipment to be used within the control area
must be tested for ferromagnetic components.
Equipment that is safe to use in the MRI suite
must be clearly labelled.
The MR suite is equipped with non
ferrous carbon dioxide fire extinguishers.
All Authorised users must be
1. Qualified in first-aid to a minimum for
appointed persons;
2. Have passed a MRI safety test; and
3. Hve read the MDA guidelines and the
CUBRIC Rules and Procedures document.
Authorisation to be granted by the CUBRIC
Operational Group (COG).
Participants must complete a two tiered
screening form to determine if it is safe for them
to be scanned.
Maintenance & cleaning staff are not permitted
to enter the Inner Controlled area. Warning
signs are posted on the entrances to the MRI
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
2
suite the signs to indicate implants that can be
affected by a magnetic field e.g. cardiac
pacemakers, hearing aids. The inner controlled
area is marked as a ‘Red Zone’ and it is
indicated that a ‘Permit to Work is required’
Reaction of participants during
scanning.
Claustrophobia
Any form of discomfort
during
scanning
e.g.
stiffness.
Heating from tattoos that
contain metallic content.
Heating from make up.
The extent of the 5 Gauss line has been
provided by a third party (MagNET, UK).
A hand-held alarm and panic button is 3
provided, which is tested at the start of each
scan session.
1
3
1
5
All participants are informed that they may
withdraw from an experiment at any time
without giving a reason.
An intercom is provided between the operator
and the participant for hearing participants. A
projection
screen
is
available
for
communication with deaf participants.
Participants with tattoos will be advised to
report immediately any discomfort.
Participants are asked to remove make-up
before scanning.
Emergency Procedures
relating to Fire.
Fire in MRI suite,
Appendix 6 of the CUBRIC Rules and 5
Procedures document details the evacuation
procedure to be followed
OSHEU have a ‘Special Risks Register’ which
includes the MR unit. The Fire Service has
access to this register, and has been invited to
make an 11D (Special Risk Familiarization)
visit.
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
3
Liquid Helium surrounding the
main magnet of the MR
system
Escape of Helium can
cause asphyxiation from
the reduction of oxygen in
the air.
Contact with helium can
cause cold burns, frostbite
and hypothermia.
Helium dropping below
50% of the capacity could
cause the magnet to fail
and a possible quench
(see risk assessment for
quench).
The equipment is under maintenance contract 5
and handling of cryogens to be carried out by
1
5
1
2
General Electric and their subcontractors. The
helium for the MRI is replenished during routine
servicing by General Electric. Air conditioning
equipment to be monitored and maintained by
Estates.
Provision of an oxygen monitor inside the
control area that activates an alarm should
oxygen level drop below safe minimums.
There is a 600 mm x 600 mm pressure
equalizing waveguide vent mounted in the RF
ceiling. An open grille is fitted in the suspended
ceiling to allow air to move in and out of the
room if the pressure changes. There is an
emergency extract fan which is part of the
scanner room ventilation design and it can be
switched on manually or triggered automatically
by the oxygen monitor and this provides an
extraction rate of 1200 cfm. The oxygen
monitor is in the control room but the sensor is
on the ceiling above the magnet.
Authorised users must have read the MDA
guidelines for MR equipment and the CUBRIC
Local Rules and Procedures document before
operating scanning equipment.
Use of laser localiser during
participant positioning before
scanning
Damage could potentially
occur to eyes if looking
straight in to the beam, or
Participants will be asked to close their eyes 2
during laser positioning.
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
4
if beam is deflected into
the eyes.
Blink response
exposure.
protects
from
accidental
Each laser light localizer
has an output of less than
1 mW at a wavelength of
approx 650 nm.
Operators are to be aware of and minimize the
risk of deflecting beam into their eyes.
These are classed as
class II lasers. Exposure
may cause dapple affect
Scanning participants
Person taken ill or injured
in scanner (unrelated to
static magnetic field)
Screening forms should eliminate anyone 5
known to be at risk.
When necessary, the GE scanner couch can be
undocked – and can be wheeled out of the
inner controlled area.
Emergency services, if necessary, will be called
(999)
All approved users will have been trained in
basic first aid (to ‘appointed person’ stage)
1
5
Scanning participants
Person injured in scanner
due to projectile effect
Screening forms should eliminate chance of 5
potential projectiles being taken in the vicinity of
the magnetic field.
If necessary, the GE scanner couch can be
undocked – and can be wheeled out of the
inner controlled area.
Emergency services, if necessary, will be called
(999)
All approved users will have been trained in
basic first aid (to ‘appointed person’ stage).
If it is impossible to remove the metallic object
(which is preventing participant from being
removed from scanner), a quench can be
initiated (but see separate risk assessment for
1
5
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
5
quench)
Quench of the magnet
(manually initiated or
spontaneous)
Helium dropping below
50% of the capacity could
cause the magnet to fail
and a possible quench).
A quench could also arise
due to malfunction of the
equipment or
ferromagnetic objects
being attracted to the
scanner. The magnetic coil
windings can touch the
inside of the scanner
causing the magnet to
become partially resistive
and start to generate heat.
One litre of helium equals
750 litres of gas. In a
quench typically, 60% of
the liquid helium will
change to a gaseous state.
This results in approx
750,000 l of gas that is
vented within 20 sec.
A Quench is only performed if the emergency 5
services need to gain access to the controlled
area or if a participant is in a life threatening
situation due to the magnetic field.
1
5
Only MRI safe or MRI compatible equipment is
allowed in the examination room. All equipment
to be marked.
All new equipment to be taken into the
examination room must be tested and approved
by the MRI Director.
All system faults will be reported and
documented in the Incident Book, which is kept
in the control room, If the fault prevents normal
safe operation the room will be signed out of
use and a sign fixed to the equipment. The
equipment must be signed over to the engineer
and back after it has been repaired and
tested.The oxygen monitor will sound if oxygen
levels become low.
Damage to the quench
pipe may cause the
following during rapid boiloff:
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
6
Excessively cooled gases
will freeze water molecules
in the area adjacent to the
magnet, causing
a dense white fog. Oxygen
in the room will be
displaced by helium,
making it difficult to
breathe.
The helium gas that
escapes during the quench
is extremely cold and may
freeze objects in its path.
Positioning participant for the
scan
MR phantoms. Used for setting
up MRI and before placing a
participant in the scanner.
Incorrect positioning of
participants in scanner can
create conductive loops
due
to
the
Radiofrequency magnetic fields.
RF burns can occur where
the arms and thighs meet.
Fluid leaks in case of
improper use, damage or
during refilling with distilled
water. Some phantoms
can contain nickel sulphate
which can cause skin
allergies
in
sensitive
persons
and
possible
carcinogenic affects.
Ensure that there is no skin to skin contact and 1
use pads between limbs. Ensure that the
participant's skin does not touch the bore of the
magnet and use MR compatible foam pads if
necessary.
1
1
Phantoms must be stored and used at 1
temperatures from 0 C to 50C.
1
1
Eating and drinking are not permitted when
working with MR phantom fluids.
Hands must be thoroughly washed with soap
and water after working with phantom fluids.
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
7
Top up with distilled water to be carried out by
GE engineers under the maintenance contract.
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
8
Persons Potentially at risk: (Guidance note 6)
Participants and staff during MRI scanning.
Additional Control measures which will need to be applied to reduce the
risk to an acceptable level (Guidance note 4)
Control measure
Date of
Implementation
Implemented
by:
Remaining
Level of
Risk
As this is a new facility and
procedure, the Control
measures and the level of
Risk assessed (assuming
compliance with those
control measures) are listed
on Pages 2-3. At this stage
no new control measures
are therefore needed.
Action in event of an accident or emergency (Guidance note 7)
The suite will be evacuated as appropriate. CUBRIC First-aiders and/or a 999 call
will be used if needed.
Arrangements for Monitoring Effectiveness of Control:
(Guidance note 8)
Periodic review by CUBRIC Management
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
9
Receipt of the Risk Assessment: (Guidance note 9)
This assessment has been issued to and read by:
Name of Recipient
Signature
Date of Receipt
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
10
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
11
Review of the Risk Assessment: (Guidance note 10)
NOT APPROPRIATE AS YET – SINCE THIS IS A NEW RISK ASSESSMENT.
Have the control measures been effective in controlling the risk?
Yes
No
Have there been any changes in the procedure or in information
available which affect the estimated level of risk from the listed
substances?
Yes
No
What changes to the control measures are required?
Date of
Name of
Reviewer
Review:
Date of Next
Review
4th July 2009
Signature:
__________________________________________________________________________________________________
Occupational Safety, Health and Environment Unit/September 2004/RISKASS Form
12