MRAB 1A Health issues related to dissecting animals/animal organs
Hazardous animals/ animal material acquired
Type
of
hazard
DRAFT
Page 1 of 5
Hazard
Control measures that reduce
the seriousness of
injury/infection from the hazard
Control measures that reduce the
likelihood of injury/infection from
the hazard
Further details
Animals may have
acquired parasitic
zoonoses
Follow government agency guidelines
if there is an outbreak of a parasitic
disease
Endoparasites: Use only animals that have
been captive bred or reared under
management,and so were are subject to
government agency inspection.
All animal materials used for dissection should be food
quality.
As food materials for pet animals (e.g. reptiles) are also
subject to government inspection, they can be used for
dissection in schools.
Ectoparasites: Remove feathers from
birds. Where mammals have been reared
out of doors, skin before use in dissection
Animals/animal
organs may have
been infected with
biological agents of
disease
Do not use animals for which the
provenance is unknown, e.g. road-kill
Use only animals that have been captive
bred or reared under management and so
were subject to government agency
inspection.
Hazardous
chemicals are used
to fix/preserve
animals
Check with supply companies before
choosing which animals/animal organs
to purchase
Follow safety guidelines given by supplier.
© CLEAPSS®, The Gardiner Building, Brunel Science Park, Kingston Lane, Uxbridge UB8 3PQ
Tel: 01895 251496; Fax: 01895 814372; E-mail: science@cleapss.org.uk; Web site: www.cleapss.org.uk
CLEAPSS Handbook Section 14.7.2
NOTE
Animals/animal organs purchased from a food retail premises
will have certification to show conformity with all food safety
legislation.
Abattoirs that supply animals/animal organs to retail outlets will
also be suitable sources. There should be no need to complete
extra paperwork etc. in order to release the materials.
Biological supply companies that source from the EU will sell
materials that have known safe provenance.
It may be sensible for dissectors to wear gloves.
There should be good ventilation during the dissection, to
disperse any fumes from the preservative chemicals.
Animal/animal organs release hazardous microbes
during dissection
Fresh frozen animals/
animal materials become
hazardous before use
Type
of
hazard
DRAFT
Page 2 of 5
Hazard
Control measures that reduce
the seriousness of
injury/infection from the
hazard
-Follow supplier’s guidelines for storage of fresh
materials, defrosting and storage after defrosting.
-If no guidelines are available, follow current
guidelines given by government agencies
controlling food safety.
- Ensure thorough hand-washing after handling
animals/animal materials
Unsafe defrosting and/or
storage conditions cause
microbial populations to
increase to hazardous levels.
When an animal is opened up
during dissection, microbes that
have proliferated inside body
cavities are released.
The chief concern comes from
perforation of the gut wall, and
subsequent release of the
microbe containing contents.
Cavities within the lungs also
cause concern.
In both of the above cases, the
cavities are open to the external
environment. Microbes that
remain in the cavity are likely to
proliferate after death.
Control measures that reduce the
likelihood of injury/infection from the
hazard
If intricate dissection of e.g. the gut
is required, then students should
use preserved animals/animal
organs.
Any organic materials, including
microbes, are denatured by the
fixation and preservation.
Preserved material is unlikely to be
metabolised by microbes.
It is therefore acceptable to make
several return “visits” to a preserved
animal/animal organ in order to
complete the dissection in stages.
For fresh animals/animal organs
The dissector should use great care in handling
fresh intestines or lungs, avoiding perforation of
the wall of the cavity. The dissector will need to be
competent in dissection technique for perforation
of the gut wall to be avoided.
To avoid the escape of microbes into the
laboratory air, the animal should be protected
inside a plastic bag/chamber or fume cupboard if
fresh animals are to be dissected and there is a
possibility of gut perforation.
Dissection of fresh whole animals should take
place in a single session.
If the possibility of release of microbes from a
cavity cannot be avoided (e.g. when inflating fresh
lungs), then the animal/animal organ should be
enclosed in a large clear plastic bag so that any
microbe-containing aerosols can be captured by
the bag.
It may sometimes be advisable to carry out the
dissection inside a fume cupboard. The door of
the fume cupboard should be positioned to protect
the dissector.
© CLEAPSS®, The Gardiner Building, Brunel Science Park, Kingston Lane, Uxbridge UB8 3PQ
Tel: 01895 251496; Fax: 01895 814372; E-mail: science@cleapss.org.uk; Web site: www.cleapss.org.uk
Details
Material that is presented for dissection should be no
more hazardous than food treated in the same
conditions
Current guidelines are summarised below:
Store fresh/ defrosted material at 50C or lower until just
before use. Do not exceed use by date.
Store frozen material in a suitable freezer at -200C. Do not
exceed maximum storage guidelines.
Defrost frozen material at 50C for a minimum of 12 hours,
and store afterwards as for fresh materials. Do not
refreeze once defrosted.
More details are available from:
http://www.food.gov.uk and http://www.defra.gov.uk
CLEAPSS Leaflet PS64 “Are we allowed to?........”, for
inflation of lungs
Public health
concerns during
disposal
Contaminated animal material may cause infection after
the dissection
Type
of
hazard
DRAFT
Page 3 of 5
Hazard
Any organic material left on
instruments, dissecting boards
or the dissector may become
contaminated with microbes
from the environment.
Any microbes released from
body cavities may contaminate
surfaces around the dissection.
Microbes released if disposed
dissected material is disturbed.
Preservative chemicals may
cause hazard is disposed
dissected material is disturbed
and/or ingested.
Control measures that
reduce the seriousness of
injury/infection from the
hazard
Control measures that reduce the likelihood of injury/infection
from the hazard
General: Several layers of newspaper should be placed under the
animal/animal organ before dissection.
The newspaper will absorb organic material emanating from the
animal/animal organ.
The dissector should prevent clothes becoming contaminated during the
dissection, either by wearing a protective apron or by rolling up sleeves.
Cuts in the skin should be covered with a waterproof dressing. It is not
necessary to wear gloves, as unbroken skin will prevent microbes entering
the body.
After the dissection, all instruments and dissecting boards etc. that have
been exposed to the animal material should be thoroughly scrubbed to
remove all traces of organic material.
The dissector should remove any protective apron etc. and then thoroughly
wash their hands using anti-bacterial hand-wash. A nailbrush may be
needed to remove material from under the nails.
Possible release of microbes from body cavities
If there is a possibility that microbes were released from body cavities,
dissection instruments should be sterilised immediately after the
dissection, using steam heat in an autoclave or 70% IDA/ethanol. After
sterilisation, instruments should be thoroughly scrubbed to remove any
organic matter. If the dissection board has been exposed to microbes, then
it should be sterilised using 1% VirKon or 70% ethanol/IDA . After
sterilisation, the board should be thoroughly scrubbed.
If a fume cupboard has been used to contain aerosols, then it should be
disinfected with 1% Virkon or 70% IDA immediately after the dissection.
All materials containing animal material should be wrapped in newspaper,
and placed in a double layer of sturdy bin bags.
The bags should be placed in a freezer until the day of refuse collection.
On the day of refuse collection, the bag containing dissection materials
should be placed in an external bin that is emptied directly by the refuse
disposal company.
© CLEAPSS®, The Gardiner Building, Brunel Science Park, Kingston Lane, Uxbridge UB8 3PQ
Tel: 01895 251496; Fax: 01895 814372; E-mail: science@cleapss.org.uk; Web site: www.cleapss.org.uk
Details
CLEAPSS Handbook Section 15.12
for details of chemical sterilisation.
1% VirKon will sterilise in 10 minutes.
70% IDA/ethanol will sterilise in 5
minutes
Both chemicals are degraded by
organic matter, so an excess should
be used.
MRAB 1B Safety issues related to dissection
Cuts from sharp instruments used in dissection
Type
of
hazard
Hazard
Control measures that reduce
the seriousness of
injury/infection from the hazard
Control measures that reduce the
likelihood of injury/infection from
the hazard
Further details
Cuts during
placement and
removal of blades
on scalpels
Avoid the use of scalpels with
disposable blades unless it is
unavoidable.
Safe practice in placement and removal of
scalpel blades, including using a forceps
for removal if necessary
See Guide “Safety in school dissections” for:
Infections from cuts
with dissection
instruments
Use new scalpel blades for each
dissection, avoiding fragments of
corroded blades remaining in cuts
- Reduce microbial contamination on
dissection instruments to the lowest
possible level by sterilisation and/or
through scrubbing before use. This
preparation can be done after previous
use, if instruments are kept clean.
- Place used instruments into detergent
solution immediately after use to remove
organic material.
Cuts from collecting
and carrying
instruments
Use dissection rolls made of sturdy
cloth to contain and carry instruments.
Place sharp points and blades into the
partitions of the roll to prevent
accidental stabbing.
Train students in how to collect and carry
instruments.
- safe practice with placement and removal of scalpel blades
- guidelines for training in safe and effective use of instruments
- use of dissection rolls to safely contain instruments
- cleaning and sharpening dissection instruments
Immediate remedial measures following a cut with a
dissection instrument
Seek help from a qualified First Aider
If injury not severe and instrument is not contaminated, First
Aider to clean and dress wound. Wound to be monitored and
medical help sought if any cause for concern.
Cuts during
dissection
- Choice of the safest instrument that
will achieve the required result for
class dissections
- do not use weak bladed scalpels to
cut very tough materials
- Demonstration dissection if student
/maturity/behaviour/skills not
considered adequate for procedure
DRAFT
Page 4 of 5
- the main uses of common dissection instruments
-Instruments sharp and in good condition,
so that little pressure has to be exerted in
use.
- Students trained in safe and effective use
of the equipment, e.g. by dissecting fibres
from celery stems.
- Teacher’s monitoring of students’ use of
dissection instruments, and appropriate
intervention when required
© CLEAPSS®, The Gardiner Building, Brunel Science Park, Kingston Lane, Uxbridge UB8 3PQ
Tel: 01895 251496; Fax: 01895 814372; E-mail: science@cleapss.org.uk; Web site: www.cleapss.org.uk
If injury severe, or instrument may be contaminated, seek
medical attention.
Cuts when cleaning
and clearing away
Type
of
hazard
DRAFT
Page 5 of 5
Hazard
Control measures that reduce
the seriousness of
injury/infection from the hazard
Control measures that reduce the
likelihood of injury/infection from
the hazard
Instruments placed in narrow
container, with sharp ends all pointing
in one direction.
Cuts from
dissection
instruments
Cuts when
removing
scalpel blades
-Avoid use of scalpels if possible
- Do not use scalpel blades more
than once as corroded blades more
likely to splinter, and metal will
embed.
-Use forceps, and/or protect from
sharp edge using paper.
- place scalpel blades immediately in
impenetrable sharps container, for later
disposal
© CLEAPSS®, The Gardiner Building, Brunel Science Park, Kingston Lane, Uxbridge UB8 3PQ
Tel: 01895 251496; Fax: 01895 814372; E-mail: science@cleapss.org.uk; Web site: www.cleapss.org.uk
Further details