3.2 Personal protective equipment (PPE) Flashcards
PPE should be regarded as the last resort to protect against risks to health and
safety. Engineering controls and safe systems of work should be considered first.
This is because:
PPE protects only the person wearing it, whereas measures controlling the risk at
source can protect everyone at the workplace.
Maximum levels of protection are seldom achieved with PPE in practice and the
actual level of protection is difficult to assess.
If RPE is used incorrectly, or is badly maintained, the wearer is unlikely to receive
adequate protection.
RPE is uncomfortable to wear and is an intrusion into normal activities.
RPE may interfere with work.
Type and level of protection required
The risk assessment will indicate the type of protection required from:
type of substance and its nature e.g. corrosive, toxic etc.
form of the substance
route of entry into the body
concentration of the substance.
There are two broad categories of RPE:
respirators and breathing apparatus (BA)
The key factors in selecting appropriate RPE are:
The level of oxygen present in the air to be breathed
The presence of toxic chemicals that may pose an imminent risk to life.
Respirators work by
filtering contaminants out of the air so that the wearer breathes
clean air
BA works by
delivering a supply of breathable air from an uncontaminated
source
Types of Respirators
Simple
filtering
respirators
Power
assisted
respirators
Types of Breathing Apparatus
Fresh air hose
BA
Powered airline
BA
Self-
contained BA
There are three main types of respirator filters:
Particle filters
Gas/vapour filters
Combined filters
Filter efficiency
P1: low efficiency: used with PF4 respirators. Do not use against fume unless
the
manufacturer can guarantee protection.
P2: medium efficiency: used with PF10 respirators. Not to be used against fume
unless the manufacturer can guarantee protection.
P3: high efficiency: used with PF20 or PF40 respirators.
Gas and vapour filters
The classification of gas and vapour filters is based on how much of the specified
contaminant they can hold in a laboratory test at set conditions.
Class 1: low capacity.
Class 2: medium capacity.
Class 3: high capacity.
RPE should only be selected and used after a justification has been made in the risk
assessment required by law. It can be used in the following situations:
Where an inhalation exposure risk remains after other reasonable controls have
been put in place i.e. residual risk.
Short-term or infrequent exposures where other controls at source are not
reasonably practicable.
While putting in place other control measures (interim measures).
Emergency escape for safe exit from an area where hazardous substances may
be released suddenly in the event of control systems failures e.g. a chlorine tank.
Emergency work or temporary failure of controls where other means of controls
are not reasonably practicable.
Where emergency rescue by trained personnel is necessary.
Selection of RPE
In order to decide on the suitability and selection the following factors must be taken
into account:
1) Chemical and toxicological related factors
2) Task-related factors
3) Worker related factors.
A confined space is
a substantially enclosed space e.g. a chamber, tank, vat, silo,
pit, trench, pipe, sewer, flue, well or small room with limited access and inadequate
air exchange. A confined space may not necessarily be enclosed on all sides.
Task-related factors that need to be considered when selecting RPE:
Work rate Wear time Abnormal temperature or humidity Power tools used Clarity of vision Clarity of communication Mobility Congested work area Potentially explosive atmosphere
Assigned protection factor (APF)
The APF is the level of respiratory protection that can realistically be expected to be
achieved in the workplace by 95% of adequately trained and supervised wearers
using a properly functioning and correctly fitted respiratory protective device.
It is calculated, under test conditions by
dividing the level of air borne contamination
by the level that would be breathed in (i.e. after the RPE has done its job). If there
were 50mg/m3 of contaminant in the air and 5mg/m3 got passed the RPE the APF
would be 50/5 = 10.
The minimum protection required (MPR) from specific RPE can be calculated by
measuring the workplace concentration outside the facepiece of the RPE and
dividing it by the maximum allowable concentration inside the facepiece of the RPE
(i.e. the WEL)
MPR = workplace concentration of contaminant outside RPE facepiece
maximum allowable concentration inside the RPE facepiece (WEL)
It should be noted that RPE may not provide the level of protection stated by the
manufacturers. This may be because:
Poor air flow or a reduction in battery power
The fitting of incorrect cartridges or a failure to replace them before saturation
Equipment incorrectly fitted or incompatible with other personal protective
equipment being worn
The presence of other contaminants resulting in a decrease in saturation time
Inadequate training in its use and particularly in the care that should be taken in
its removal
Poor maintenance and inadequate storage resulting in the face piece being left
exposed
Damage occurring during use and inadequate monitoring and supervision to
ensure the equipment was always used when required
The equipment might not have been manufactured to the appropriate standards.
There are two basic types of RPE fit testing
Qualitative fit testing: is a simple pass/fail test based on the
wearer’s subjective assessment of the leakage, via the face seal
region, of a test agent. If the wearer can detect the test agent
(either a bitter or sweet tasting aerosol; or an odourous
compound) the fit test is failed.
Quantitative fit testing: provides a numerical measure of the fit that is called a fit
factor. These tests give an objective measure of face fit. They require specialised
equipment and are more complicated to carry out.
Maintenance is a requirement for all RPE, except for single use RPE, and should be
carried out by properly trained personnel. An effective maintenance system includes
the following:
Examination: checking for faults, damage, wear and tear, dirt etc.
Testing: to ensure PPE is operating as intended
Cleaning: including disinfection if appropriate
Repair
Replacement.
Records of examination and testing must be kept for five years.
When choosing safety eye wear the following should be considered:
The nature of the hazard The risk factors Intended use Type of lens Ocular performance Comfort and fit Compatibility with other PPE
After considering the specific requirements of skin and eye protection, the following
general issues should be considered:
Consultation and user trials
Comfort of the equipment
That everything purchased carried the CE mark
That all personal protective equipment provided met the appropriate standards.
The following training should be given to users of PPE:
The health risks of the chemical in use.
The type of personal protection to be used and the reason for its use.
The methods to be used for putting on and taking off the equipment without
causing contamination including decontaminating or discarding gloves after use.
The methods of examining the equipment for damage or degradation, particularly
gloves, and for reporting defects and obtaining replacements.
How to store the equipment correctly.
How to carry out self-examination of the skin and the action to be taken if
problems were to occur.
Other than training, there are practical measures that can be taken to increase the
correct use of PPE. These include:
Management leading by example
Employees being involved in the selection of the equipment
Ensuring the availability of a range of sizes in gloves and fully adjustable face
shields
Ensuring employees were required to sign for their equipment and maintaining
records of issue
Issuing the equipment on a personal basis and providing adequate storage
facilities
Using propaganda, signs and posters and incentive schemes
Monitoring compliance in the use of the equipment with a recognised code of
discipline for non-use
Monitoring the effectiveness of the equipment issued and replacing it with an
alternative type if problems were encountered.
