When undertaking experimental work/procedures, you are required to follow the College
rules set out below, failure to do so may result in your work being curtailed or stopped
altogether and more importantly you could be putting yourself and your fellow workers in danger,
before starting any experimental work you MUST read and understand the following material.
THE POINT OF DOING AN ASSESSMENT IS TO HELP YOU WORK SAFELY AND NOT JUST TO LIST THE DANGERS THE CHEMICALS MAY POSE.
SO KEEP THIS IN MIND WHEN UNDERTAKING YOUR COSHH ASSESSMENT
The key points are risk assessment and the COSHH regulations.
of Substances Hazardous to Health (COSHH) Regulations 1988, 1994, 1999 & 2002 are
designed to protect workers or others against substances considered hazardous
to health in the workplace. COSHH assessments must be completed for any process
or procedure that involves the use of hazardous substances. Hazardous
substances may be found in nearly all working environments. Their effects may
include the following and others:
through ingestion, inhalation or skin absorption, for instance, losing
consciousness or death as a result of being overcome by toxic fumes
irritation or loss of sight from eye contact
irritation or dermatitis from skin contact
as a result of developing an allergy to substances used at work
or other mutagenic effects, which may appear long after the exposure to the
chemical that caused it
from bacteria and other micro-organisms
YOU ARE LEGALLY REQUIRED TO ASSESS THE RISKS ASSOCIATED WITH ANY OPERATION
BEFORE YOU START WORK.
carrying out a procedure with hazardous materials (including biological tissues
cell culture and micro-organisms)
any risk must be identified and assessed. It is the responsibility of the
Supervisor and the laboratory worker to jointly assess the hazards
associated with their work. Except in the very low risk situations it will be
necessary for the assessment to be in the written form using a COSHH assessment
pro forma. The process assessor and the process supervisor must sign the
supervisor may delegate the task of assessment, but, s/he cannot delegate the
supervisory responsibility. The process supervisor has executive control of and
health and safety responsibility for the process and s/he must ensure that the
assessment is complete and appropriate then sign it. The main findings of this
assessment must be recorded in writing and then reviewed if there has been a
significant change in the work. It is mandatory, BEFORE work is commenced,
that the assessment is recorded and a copy is held locally in laboratory master
records of COSHH assessments, this record a requirement for ALL laboratories
within the College.
The College Safety
Group will review in detail selected COSHH assessments to assure that hazards have been
properly identified and the appropriate control measures are in place to
minimise risk. Note: All COSSH forms will be inspected as part of the annual laboratory
adit process along with material safety data sheets (MSDS), which you are required to keep.
Most COSHH assessments will use as their starting point the MSDS provided by the chemical supplier
the sheet should help you identify the risks.
It is your responsibility if you are purchasing a chemical for the first time to identfy the risks
associated with it's use before purchase, so that you don't subsequently discover after it has been delivered
that it is too toxic/hazardous to use.
are available from the College COSHH Adviser or from the documents page of the
University Health and Safety website.
require the following steps are taken in the assessment, carried out by
the person with the most knowledge and experience of the process, i.e. the process
assessor. The assessor should carry this out jointly with the process
Step 1. Identify the hazardous substances
used or created by your procedure. What is the hazardous substance? Is it:
or mixtures of substances classified as dangerous by the Chemicals
(Hazard Information and Packaging for Supply) Regulations 1994 (as
amended) (CHIP). These substances can usually be identified by their
hazard-warning label and should have a material safety data sheet.
with occupational exposure limits (OEL). These are published in the HSE Occupational
exposure limits publication EH40 available in the Safety Office.
agents and other micro-organisms directly connected with work.
- Any kind
of dust in a concentration specified by COSHH.
- Any other
substance, which has comparable hazards to people’s health, but which for
technical reasons, may not have a hazard label eg some pesticides,
There are a
number of other materials that are not actually covered by COSHH, such as
asbestos, radioactive materials, lead and scheduled materials: these are
covered by their own regulations. However, an assessment must be conducted.
Step 2 Consider the risk these substances
present to people’s health. Assessing the risk involves making a judgement of
how likely it is that a hazardous substance will affect someone’s health. How
much of the substance is used? How could people be exposed to it? Who could be
exposed to the substance and how often? With some relatively harmless chemicals
the assessment will amount to establishing normal safe laboratory practice.
Chemicals that present the following risks MUST ALWAYS be formally assessed:
Highly toxic chemicals
Known or suspected human carcinogens
Chemicals that cause reproductive damage or harm to the unborn child
Chemicals that may cause drowsiness
Chemicals for which special first aid provisions are requiured, e.g.
Chemicals for which there a workplace limit has beeen established and there
is a possibilitty this could be exceeded
Where there is potential risk of asphyxiation
Explosive, pyrophoric and biological hazzards
Step 3 If you identify significant risks
then decide what precautions are needed to remove or reduce those risks to an
acceptable level. What control measures are required? What are the first aid
measures in case of an accident? What are the disposal methods?
Step 4 Ensure that control measures are
used and maintained so that exposure to hazardous material is prevented or
adequately controlled. This may involve changing the process so that the
hazardous material is not needed or replacing it with a safer form. If
prevention is not practical then the control measures must be improved so that
exposure is adequately controlled and OELs are not exceeded.
should be properly informed, trained and supervised. For certain very hazardous
materials, exposure must be monitored and there should be health surveillance,
the use of these materials is not permitted without prior consultation with the
College Safety Officer. Any control measures that are used must be maintained
and tested e.g. the fume cupboards are tested and serviced by Buildings and
Estates Division. Any defects must be reported to the College Safety Officer.
COSHH asssessments must be signed and dated by each worker who will use that chemical,
once signed the assessment needs to be stored in an accessible location within the
laboratory where the chemical will be used, they are meant to be read and used. they should
be filed in a systematic way.
Note: you may use the same chemical in several different contexts, this may require more than
one assessment for it.
THE OBJECT OF THE ASSESSMENT IS NOT TO SIMPLY LIST HAZARDS, BUT TO SPECIFY HOW THOSE
HAZARDS WILL BE MITIGATED.
Bottles. All bottles of chemicals must be
clearly and correctly labelled, and ONLY those chemicals in use or likely to be
required in the near future should be kept in the research laboratories.
Over-labelling of original manufacturers labels is forbidden. Labelling must
not be liable to facile removal e.g. on spillage of contents or splashing with
Mercaptans/Thiols.The College is obliged to report the use of such
chemicals to other areas of the campus to avoid any confusion over possible gas
leaks. On any occasion, before handling mercaptans/thiols, workers must report
their intention to the College Safety Officer.
of Potentially Hazardous Air/Moisture-sensitive Compounds. Any research worker intending to
use a potentially hazardous air/moisture-sensitive compound (eg organolithium
reagents) MUST discuss the appropriate techniques for safe handling with their
supervisor and College Safety Officer and fill out a COSHH Assessment form BEFORE starting the work. A
copy of the Aldrich Technical Bulletin AL-134 “Handling Air-sensitive Reagents”
must be consulted.
toxic materials. MUST
only be handled in the presence of at least one other experienced worker.
cyanides are controlled substances and will only be allowed to be used on presentation of a
fully completed COSHH assessment form, which has been signed by the Research
Supervisor and the College Safety Officer. Following HSE guidelines for first aid; an oxygen cylinder and mask must be
available for the duration of the work and staff should be trained in the adminstration of oxygen. Only the required amount for the
risk-assessed reaction/procedure should be obtained and all residues MUST be destroyed immediately
after use. Records of use MUST be kept.
ALL HAZARDOUS SUBSTANCES MUST ONLY BE USED WITHIN CORE WORKING HOURS (8.30 am-5.00 pm)AND IN THE
PRESENCE OF ANOTHER EXPERIENCED WORKER.
HYDROFLUORIC ACID (HF)
HF presents a particular hazard to workers, as exposure to HF can be potentially fatal or result in very serious injuries.
HF is used within the College as an etchant for processing and sample fabrication within the cleanrooms in the Physics Building.
Any other use of HF within the College MUST be reported to and sanctioned by the College Safety Officer before any work starts.
HF MUST ONLY BE USED BY DESIGNATED AND TRAINED USERS, USE BY OTHERS IS STRICTLY FORBIDDEN, A LIST OF AURTHORISED USERS NEEDS
TO BE KEEP BY ALL CLEANROOMS/LABORATORIES USING HF, HF SPECIFIC DECONTAMINATION/FIRST AID MEASURES MUST ALWAYS BE AT HAND WHEN HF IS BEING USED
AND LABORATORY HF PROTOCOLS STRICTLY FOLLOWED
and other controlled substances. The use of poisons, controlled substances and other
forensic products under Schedule 1, 2, 3 and 4 are controlled through the Home
Office. Many can only be obtained using special ordering procedures. Scheduled
substances may only be ordered by academic staff, post doctoral research
personnel and certain trained technical staff. All scheduled substances must be
stored under lock and key and records of use must be kept. Their use must be
subject to risk assessment as above.
JOHN CAN WE LINK TO THIS LIST Some examples of S1 Poisons and Red list
of prescribed substances are:
and its compounds (except those containing less than 0.0075% As)
Cadmium and its compounds Carbon
acid and its salts
Hydrogen cyanide and cyanide salts gamma-Hexachlorocyclohexane
Mercury and its compounds Malathion
Nicotine and its salts Pentachlorophenol
Polychlorinated Biphenyls Simazine
regulation on Drug Precursors. Under 2005 EC regulations the purchase of certain drug
precursor chemicals requires a licence. The use of these materials must be
recorded and a return must be completed for the Home Office. Further details
are available from the College COSHH Adviser.
Under the Chemical Weapons Convention, the importation, use and production of
certain chemicals and precursors must be recorded. There are restrictions on
placing orders for these chemicals. Further details are available from the
School COSHH Adviser.
Micro-organisms. Micro-organism, cell culture, or
human endoparasite, including any which have been genetically modified, which
may cause any infection, allergy, toxicity or otherwise create a hazard to
human health must be assessed under COSHH. Such materials are also subject to
the rules on handling micro-organisms.
End of Link
workers must be aware of the hazard associated with solvents; many are highly
flammable and toxic and therefore should also be assessed under COSHH.
solvents are very volatile and so may easily be inhaled and will often
cause drowsiness even if they are not toxic. Some can cause irritation or
dermatitis if spilt on the skin.
should be stored in flameproof cabinets containing metal trays capable of
retaining at least 110 per cent of the contents of the largest container
stored. Large quantities must not be stored in the open laboratory. No
more than 50 litres of highly flammable liquids may be stored in any one
and non-flammable solvents should not be stored together.
solvents should not be stored in refrigerators or freezers unless these
have been spark-proofed.
- NEVER put
solvents for disposal down the sink.
- As there
is a real possibility of explosion of waste acetone and chloroform in the
presence of alkali, ACETONE should only be added to Acetone only
waste bottles; if for some reason it is contaminated, then it should be
sent for disposal in a separate container clearly labelled ‘Do not mix
with other waste solvent’. Waste solvent should be separated into bottles
(Chloroform, dichloromethane etc) and
waste solvent (ethanol,
of solvents should be transported around the building using the carriers
available for them and not carried in the hand.
must not be left on the floor, on top of shelves and they should not be kept
on bench working surfaces for longer than necessary.
general, waste solvent which contains a high concentration of acid or base
should not be indiscriminately added to general waste solvent containers
but labelled and disposed of separately.
reactive materials before placing in waste solvent bottles.
cryogenic fluid is normally defined as one which is manufactured, stored,
handled or processed at temperatures at or below 188 K (-85°).
- CRYOGENS MUST ONLY BE HANDLED BY PERSONS WHO HAVE BEEN GIVEN
INSTRUCTION IN THEIR SAFE USE
nitrogen, helium and other cryogenics including solid CO2 must only be
stored or conveyed in approved Dewar containers. Sealed containers must
NEVER be used due to build-up of dangerous pressure,liquified gases expand
uapproximately 700 times their liquid volume at room temperature. This is a
particular danger with semi-sealed conatiners like helium dewars
should be taken when handling cryogenic liquid storage Dewars. Avoid
mechanical shock and damage to the vessel’s vacuum insulating jacket.
Breakdown of the insulation will cause rapid boil-off of the liquid
contents, producing large quantities of gas and a possible increase in
pressure within the vessel.
helium Dewars should not be tilted.
should only be used for the specific liquids for which they are designed.
transferring liquid nitrogen and other cryogenics from storage containers
to liquid nitrogen refrigerators or Dewar flasks (including small vacuum
flasks) MUST use facemasks or goggles, and suitable gloves.
gloves should always be worn when handling anything that is or may have
been in contact with cold liquids or vapour. Gloves should be a loose fit
so that they are readily removed should liquid splash on to them or into
is drawn to the need for adequate ventilation when using liquid nitrogen
and other cryogenics including solid CO2. Never remain in a small enclosed
space or travel in a lift with a Dewar of liquid nitrogen or other
cryogenic material. Such area should be fitted with an oxygen depletion
monitor. Liquid nitrogen and helium, although non-toxic, produce large
quantities of gas which can cause an oxygen deficient atmosphere and
transfers of cryogenic liquids and venting or purging operations should be
carried out in well ventilated areas.
of the skin to low temperature can produce effects on the skin similar to
a burn. Naked or insufficiently protected parts of the body coming into
contact with very cold uninsulated pipes or vessels may stick fast by
virtue of the freezing of the available moisture and the flesh may be torn
on removal. Protective clothing for the handling of low temperature
liquefied gas serves mainly to protect against frost burns.
exposure to cold can result in frostbite. Prolonged inhalation of cold
vapour or gas can damage the lungs. Cryogenic liquids and vapour can
damage the eyes.
- Please note: The low
viscosity of cryogenic liquids means that they will penetrate woven or
other porous materials much faster than for example water.
- FIRST AID NOTE FOR CYOGENIC BURNS: The most important thing to do is
imediately douse the area affected with copious water if spilt over the
whole body a shower should be used
of cylinders inside laboratories should be kept to the smallest reasonably
practicable number. Spare cylinders should be kept in the storage compound.
qualified technicians are authorized to handle compressed gas cylinders. Correct
handling procedures are important to avoid damage to cylinders or injury to
personnel. After being moved and before being put into use, it is important to
carry out routine checks that the identification markings on cylinders are
correct, the cylinders are safely installed and that the valves, regulators and
other ancillary equipment are intact.
One of the
main dangers is over-pressurisation of the cylinder in the event of a fire.
This is particularly so when the gas has liquefied under pressure. Cylinders
should be stored away from any source of heat such as boilers etc and should
always be sited at a safe distance from other high fire risks.
and hose connections are the weakest links in the system and failure of these
is a known cause of fire and explosions. So far as is practicable gases should
be distributed through suitable fixed metallic pipework. When flexible gas
pipes are necessary they should be suitable for the duty intended and
preferably be of metal or metal armoured type. Pipes should be as short as
reasonably practicable and protected from possible physical heat or corrosion
damage. Flexible hoses should be replaced periodically in accordance with the
following general points apply.
- Toxic or
asphyxiant gases such as CO2 can build up in confined spaces.
gas cylinders are colour coded according to the gas contained. Cylinders
containing flammable gases are red or part red and have a left-handed
thread; non-flammable gas cylinders have a right hand thread for fitting
regulators should be fitted by trained personnel only, training must be
provided for new research workers before they change cylinder regulators.
over-tighten regulators when fitting and do not lubricate threads,
colours, valve threads or markings, should never be interfered with.
must be stored or used upright and strapped to a secure support away from
should only be moved using the appropriate equipment. Safety shoes and
cylinder trolleys are to be used, available from stores. Laboratory
workers are required to move gas cylinders; qualified technicians will assist
or advise when available.
should only be used for the gas identified on the regulator.
which assist fire, eg oxygen, should be stored separately to flammable
- The door
to the laboratory MUST be labelled with the gases in use to inform fire
fighters in the event of a fire.
not in regular use should be returned to the stores.
workers must make full use of the safety equipment available and have the
requisite items at hand before commencing a potentially dangerous experiment.
to equipment such as clothing, respirators, helmets, ear protectors, safety
boots and eye protectors and gloves required for use in hazardous situations.
PPE such as ear protection and filter respirators should be considered as the
“last resort” once all other measures to reduce a risk to acceptable levels
have been taken. Doing the job by a safer method should always be considered
first. PPE must be suitable for the risks involved and must be maintained
(including cleaned) in an efficient state and working order. Under the latest
COSHH regulations, filter respirators must be tested for face fit.
the appropriate type of disposable gloves are worn for a given application – for
example nitrile gloves may not be the best choice for many organic solvents. It is YOUR
responsibility to ensure the gloves your use are resistant to the chemicals you are handling,
You MUST in your COSSH assessment check correct gloves are used
working with biological tissues, cell culture or micro-organisms, a laboratory coat
with side fastenings is recommended. This coat MUST be kept separate from other lab coats
and outside clothing.
protection must be chosen that is appropriate to the risk, visors should be
used when handling large quantities of corrosive or hazardous materials but
safety spectacles may be used for small quantities. Eye protection to BS EN
170 is suitable for use when there is a risk of UV radiation.
new European standards cover the specification for PPE in given situations.
risk of fire and explosion in laboratories is caused by the use of unsuitable
equipment in explosive atmospheres or in areas where quantities of flammable
vapour are present. In such an environment, it is essential that non-sparking
or spark-proof apparatus is employed and that apparatus with moving parts
should not be run in such a manner as to overheat. If such a fire should
arise, switch off the apparatus and use the appropriate extinguisher, i.e. a CO2
extinguisher or dry powder extinguisher if a fire involves solvents. Under NO
circumstances should water or foam extinguishers be used.
containing heating elements used for heating liquids etc should not be allowed
to overheat and should remain covered by the liquid. It is preferable, where
possible, to use the modern type of fail-safe connection with an ejector plug
or fusible link.
Do not use
immersion heaters of water-type for heating baths of fluids other than water.
fire hazard, stocks of flammables in laboratories should be kept to a minimum.
If materials requiring special fire-fighting materials are stored in the
laboratory, a suitable notice showing the correct fire-fighting instructions
MUST be displayed on the door of the laboratory.
Definitions.The flash point is the temperature at which a
substance gives rise to an ignitable vapour. If a substance is cooled below
its flash point, the danger of ignition through the vapour reaching nearby
flames, sparks or hot surfaces is much reduced. The minimum
ignition temperature is that at which the vapour will spontaneously catch fire
in air. Thus if vapour from a liquid at room temperature is carried by a
draught into contact with a surface at a temperature above the ignition
temperature the vapour may ignite and burn back to ignite the liquid. The
minimum ignition energy of a flammable mixture of given composition and
at a specific temperature and pressure is that below which ignition cannot be
produced: operation below this level is the underlying principle of
intrinsically safe equipment.
chemicals, especially organic substances, should be regarded as potentially
hazardous unless they are known to be otherwise. Many substances which are not
obviously corrosive or toxic can act as cumulative poisons. Most chemicals can
be handled by simple methods provided that a little common sense is used.
However, the well known action of dusts, vapours and oils in causing lung, skin
and other diseases must be kept in mind. A surprisingly large number of
substances are capable of causing diseases to develop after a period of
apparent immunity e.g. asbestosis, cancer.
be taken to avoid inhalation of vapours, ingestion of liquids and solids, and
all unnecessary contact with the skin. Eating, drinking, smoking,
application of cosmetics and sucking pencils can all lead to accidental
ingestion or skin absorption. The prime preventive against accidental
contamination is good laboratory practice. Use of fume cupboards, and the wearing
suitable protective equipment including goggles should always be used wherever
appropriate to minimise the risk to personnel.
should be stored in such a way as to minimise the risk of accidental contact
between incompatible chemicals, which could arise from breakage, spillage or fire.
The table below provides a list (not exhaustive) of chemicals that need to be
segregated on the grounds of potential reactive or toxic hazard. It is the
responsibility of those working with chemicals to ensure they have assessed
these risks and have stored all chemicals appropriately.
cupboards should never be used for the storage of chemicals due to the very
real risk of spillage. It must always be remembered that a fume cupboard is a
working environment please ensure your safety and the safety of others by not storing chemicals
in the fume cupboards. Occasionally however, the storage of material in fume
cupboards may be unavoidable, but if this does occur the chemicals must be in clearly labelled
containers, with all potential hazards clearly indicated and with all
containers placed in a tray in order to contain any accidental spillage.
labelled samples and chemicals pose an unacceptable risk to everyone and will
NOT be tolerated.
The tables below give specific information on some common reactive chemical hazards and
chemical incompatabilities leading to toxic/hazardous products. NOTE: It is YOUR
responsibility to check reactive hazards
List of reactive chemical hazards
list is NOT complete, indicative only; it is YOUR responsibility to check
reactive hazard risks)
substances in the left hand column must be stored and handled so that they can
not accidentally come into contact with the corresponding substances in the
right hand column under uncontrolled conditions because violent reactions may
occur. IT IS ESSENTIAL THESE CHEMICALS ARE SEGREGATED IN ORDER TO MINIMISE THE
RISK OF ACCIDENTAL CONTACT
ACCIDENTAL CONTACT WITH, AND KEEP SEGREGATED FROM:
acid, nitric acid, hydroxyl containing compounds, ethylene glycol, perchloric
acid, peroxides and permanganates
nitric acid and sulphuric acid mixtures
bromine, copper, silver, fluorine and mercury
and ALKALI EARTH metals
dioxide, carbon tetrachloride, other chlorinated hydrocarbons.
NOTE: DO NOT use water, foam or dry chemical on fires involving these metals,
extinguish with dry sand
chlorine, calcium hypochlorite, iodine, bromine and hydrogen fluoride
metal powders, flammable liquids, chlorates, nitrites, sulphur, finely
divided organics or combustibles
acid, hydrogen peroxide
acetylene, butadiene, butane and other petroleum gases, sodium carbide,
turpentine, benzene and finely divided metals
salts, acids, metal powders, sulphur, finely divided organics or combustibles
ACID AND CHROMIUM TRIOXIDE
acid, naphthalene, camphor glycerol, turpentine, alcohol and other flammable
acetylene, butabiene, butane and other petroleum gases, sodium carbide,
turpentine, benzene and finely divided metals,
methane, phosphine and hydrogen sulfide
peroxide, nitric acid and any other oxidant
aqueous or anhydrous
Chromium, iron, most metals and metal salts, any flammable liquid,
combustible materials, aniline, nitromethane
Nitric acid, oxidising gases
ammonia (aqueous or anhyd.)
fulminic acid, ammonia
acid, acetone, alcohol, aniline, chromic acid, HCN, hydrogen sulphide,
flammable liquids and nitratable substances
bases peroxides and amines
grease, hydrogen, flammable liquids, solids or gases
anhydride, bismuth and its alloys, alcohol, paper, wood grease oils.
(organic or mineral) NOTE: avoid friction when handling also store at low
ammonium salts metal powders, sulphur finely divided organics and combustible
ethylene glycol, benzaldehyde, sulphuric acid
oxalic acid, tartaric acid, fulminic acid, ammonium compounds
nitrate and other ammonium salts
ANY oxidisable substance, such as
ethanol, methanol, glacial acetic acid, acetic anhydride benzaldehyde,
glycerol, ethylene, ethyl acetate etc…
Toxic chemical hazards
below are some chemicals which, if they come into contact will produce a toxic
hazard. NOTE: this list is not exhaustive and very much a partial list to act
as a guide for common hazards. It is YOUR responsibility to ensure you
understand and minimise the risk of the accidental production of toxic products.
substances in the left hand column should be store and handled with care so
that they cannot possibly accidentally contact the corresponding substance in
the centre column, because otherwise toxic materials (in the right hand column)
would be evolved.
ACCIDENTAL CONTACT WITH:
PRODUCT IN CASE OF CONTACT
or HYPOCHLOROUS ACID
BRASS, ANY HEAVY METALS
ALKALIES or REDUCING AGENTS