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IOSH – A Guide to
Respiratory Protective Devices
Gary Pharo
WE DESIGN AND MANUFACTURE
WORLD CLASS RESPIRATORY PROTECTION
Since 1926 Sundström Safety has
been dedicated to protect people
against polluted air.
We can present a complete
system with various respiratory
protective devices for most
applications and we do so
globally
Our company is managed by the
third generation of the
Sundström family.
AGENDA
❑ Selecting RPE
❑ Particle sizes
❑ Legislation
❑ Types of RPE and how they work
(plus some additional items!)
❑ Filtration efficiency
❑ Pandemics and RPE
SELECTING RESPIRATORY PROTECTIVE EQUIPMENT
Right for the Hazard
Right for the Task
Right for the Person
Things you need to consider include:
Pre-existing Health conditions
Contact lenses/ Spectacles
Facial hair and markings
RIGHT FOR THE PERSON
FACIAL HAIR AND
PROTECTION FACTOR
0
200
400
600
800
1000
1200
Clean shaven Stubble Beard
< 10 %remains
< 1 %remains
On average, stubble will reduce the protection level by more than 90%
Beards reduce the protection level by
more than 99%
Amosite (asbestos)
fibres on a human
hair measuring
around 10-20
microns long and
perhaps 1 micron
wide
RIGHT FOR THE TASKThings you need to consider include:
Immediately Dangerous to Life and Health
Work rate
Wear time
Abnormal temperature or humidity
Flammable or explosive atmospheres
Lack of oxygen
Vision
Communication
Mobility
Other PPE
RIGHT FOR THE HAZARD
Gas / Vapours Lack of Oxygen Particles
Two types of contaminants – three risk areas
PARTICLE SIZES
0.0001 0.001 0.01 0.1 1 10 100 1 000 10 000
TOBACCO SMOKE
WOOD/ SAWDUST
METAL DUST
VIRUSESBACTERIA
POLLEN
FIBREGLASS
VEHICLE EXHAUST EMISSIONS
ASBESTOS
WELDING FUME
COAL DUST
FLOUR DUST
CEMENT DUST
BIOCIDES IN SPRAYFORM
Visibility limit 17 µm
RESPIRABLE SILICA
PAPER DUST
Gas Molecules
Penetrate into lungs
Mostly caught in nose or throatPenetrate into lungs and can enter blood stream
PARTICLE SIZES
Bacillus
Bacteria
0.5 μm
Exhaust
Emission
2.5 μm
Red Blood
Cell 7 μm
Dust
particle
10 μm
Covid-19
0.06 μm –
0.14 μm
COUGHING/ SNEEZING
The average human cough expels:
8,000 particles when well, increasing to
over 75,000 when ill
Range in size from around 1000 microns down to around 0.1 micron
>95% are smaller than 1 micron
>99% are smaller than 10 micron
National Institute for Occupational Safety and Health, Health Effects Laboratory Division, Morgantown, West Virginia
University of Alberta, Edmonton, AB, Canada
(References: 1)
PARTICLE SIZE AND FALLING VELOCITY
Particle diameter Falling velocity Fall time for 1m
10 µm (0,01 mm) 47 cm/min …2,2 min
5 µm (0,005 mm) 11 cm/min …9,1 mim
1 µm (0,001 mm) 27 cm/hour …4 hours
0,5 µm (0,0005 mm) 6,8 cm/hour …15 hours
0,2 µm (0,0002 mm) 1,1 cm/hour …91 hours
Where respiratory protective equipment (RPE) is used as a
control measure under Health and Safety Legislation, it is vital
that the selected RPE is adequate and suitable.
For sensitisers, carcinogens and mutagens RPE must reduce
exposure to as low as reasonably practicable, and in any case
to an acceptable level (e.g. below any applicable Workplace
Exposure Limits or Control Limits).
WHAT DOES LEGISLATION REQUIRE?
Mosteffective
Least effective
HIERARCHY OF CONTROLS
Eliminate the hazard
Protect the worker with PPE
Change the way people work
Isolate people from the hazard
Replace the hazard
TYPES OF RPEBreathing apparatus
The user is supplied with breathable
air from a non-contaminated source
Not dependent on surrounding
atmosphere
Filter Purification
Air passes through a
filter that
remove contaminants
Dependent on
surrounding
atmosphere
MostEffective
Least effective
HOME MADE MASKS
Needle sizes vary from
c.5300 microns (5 gauge)
to
c.600 microns (23 gauge)
NOT PPE!!
Cloth masks should not be recommended for HCWs,
particularly in high-risk situations, and guidelines need
to be updated (Reference: 2 MacIntyre CR, Seale H, Dung TC, et al)
On average the
equivalent of
5000 virus
particles could
pass through
each needle hole
with each breath
PITTA MASKS
In a recent test of Japanese Pitta Mask filtration
efficiency, they managed to filter
Just 64% of 2.5 micron size particles
And
0% of 0.3 micron size particles
NOT PPE!!
SURGICAL FACE MASKS
The main intended use of most surgical masks is
to protect the patients from infective agents from
the noses and mouths of the staff and, in certain
situations, additionally to protect the wearer
against splashes of potentially contaminated
liquids.
They are not PPE or RPE
NOT PPE!!
DISPOSABLE FACE MASKS
Disposable come in many shapes, colours and sizes…but normally only in ‘1 size fits all’
Disposable masks will only protect against particles in limited concentrations
Some (coloured grey) also offer relief from nuisance organic vapours below the WEL
WORKING PRINCIPLE OF DISPOSABLE FACE MASKS
Disposable masks form a seal around the aural nasal area and
require the user to be clean shaven in the area the mask seals.
If being used as a control measure under COSHH a face fit test
should be undertaken to ensure they are suitable and sufficient
RE-USING DISPOSABLE MASKS
1. What is the effect on the
filtration media?
2. What is the effect on the fit of
the mask
3. What harm could the cleaning
solution do to human skin
No method is currently proven nor
currently supported by any manufacturer
(that I know of).
HALF MASKS
FULL FACE MASKS
WORKING PRINCIPLE OF HALF AND FULL FACE MASKS
Half Face masks form a seal around the aural
nasal area and require the user to be clean
shaven in the area the mask seals.
Full Face masks form a seal around the face
and aural nasal area and require the user to be
clean shaven in the area the mask seals.
If being used as a control measure under COSHH a face fit test should be undertaken to
ensure they are suitable and sufficient
WORKING PRINCIPLE OF HALF AND FULL FACE MASKS
Assigned Protection Factors
For particles P1 = 4; P2 = 10 P3 = 40
For gas only or combined gas & particles = 20
Assigned Protection Factors
For particles P1 = 4; P2 = 10 P3 = 20
For gas only or combined gas & particles = 10
POWERED
AIR
PURIFYING
RESPIRATORS
WORKING PRINCIPLE OF POWERED AIR PURIFYING RESPIRATORS
(LOOSE FITTING HEADTOP)
▪ They must be used in conjunction with an approved headtop or facepiece and the appropriate certified filter
▪ Powered Air Purifying Respirators combined with a Loose Fitting Headtop are suitable for people with facial hair.
PAPR HEADTOPS
PARTICLE FILTER FILTRATION TECHNOLOGY
➢ Particle penetration increases at higher airflow
rates than 95 l/min
➢ Small filter area gives a short service life for the
filter
➢ Electrostatic charged filter material loses its
charge when it becomes wet
➢ Hard for the user to determine when the filter lost
its filtration efficiency and the particles goes
straight through the filter.
Electrostatic filter
• Air velocity >250 l/min
• Large filter area
• Humidity resistant
• Filtration efficiency increases over time
Mechanical filter
PARTICLE FILTER FILTRATION TECHNOLOGY
PARTICLE FILTER VS PARTICLE FILTER
Respiratory protection is not created equal; this isn’t to say that those other masks/ filters may not
be suitable for certain tasks, but Sundström solutions far exceed the current standards
Class Filtration
Efficiency
Maximum Inward
Leakage
Surgical Mask ?? > 40%
FFP1 80% 20%
FFP2 94% 6%
FFP3 99% 1%
P3R 99.95% 0.05%
100,000 particles with each
breath, what’s behind the filter?
? Probably c. 40,000
Up to 20,000
Up to 6,000
Up to 1,000
Up to 50
99.997% 0.003%
WEARING RPE DURING A PANDEMIC
WEARING RPE IN EVERYDAY LIFE
Wearing a mask in public has little or no beneficial effect
There are issues with
• Fit• Touching mask• Disposing of mask• Reusing mask• Comfort of mask• Facial hair• Wearing it the right way up
There may be some small benefit to infected people reducing aerosol transmission
A study by Centre for Cardiovascular Sciences, Edinburgh University, Edinburgh, UK showed that for the first time that a wearing a facemask appears to abrogate the adverse effects of air pollution on blood pressure and heart rate variability.
These were the results from penetration tests of various mask types (Reference: 3)
* I have added the homemade mask data from the more recent Wake Forest Institute for Regenerative Medicine0 20 40 60 80 100
cotton handkerchief
worst homemade mask
best homemade mask
surgical mask
cycle mask D
cycle mask C
cycle mask B
cycle mask A
dust respirator B
dust respirator A
disposable FFP2
72
99
21
20
17.2
44.9
15.2
18
0.1
1.5
3.4
% Penetration
penetration of 2.5 micron particles
WEARING RPE IN NON-SURGICAL SETTINGSThings to consider:
Covid-19 has been recovered from face masks days after use, so dispose of used materials accordingly
Covid-19 will survive on various surfaces for hours, even days
Covid-19 can also enter via the eyes, so consider eye protection
Try to ensure all PPE is as comfortable as possible to avoid fiddling
Determine good donning and doffing procedures for all PPE
Decontaminate any reusable PPE in line with manufacturers guidelines
Soap and hot water or 70% alcohol (isopropyl alcohol/ ethanol) destroy covid-19
WEARING RPE IN HEALTHCARE SETTINGS
Staff are wearing PPE for 12 hours sometimes longer
So far over 20,000 healthcare workers have contracted covid-19
23% of people wearing N95 or surgical masks in a pandemic contract the disease
We need to consider if current recommendations for RPE in a pandemic are suitable and sufficient
We Design & Manufacture
World Class Respiratory Protection
Q & A
KEEP BREATHING
REFERENCES Legislation
➢ The Health and Safety at Work etc Act 1974
➢ COSHH - Control of Substances Hazardous to Health Regulations 2002
➢ CLAW - Control of Lead at Work Regulations 2002
➢ CA - Control of Asbestos Regulations
➢ EN 529:2005 - Respiratory protective devices. Recommendations for selection, use, care and maintenance
➢ HSG 53 - Respiratory protective equipment at work: A practical guide
➢ OC 282/28 - Guidance on respiratory protective equipment (RPE) fit testing
Scientific
1. Cough aerosol in healthy participants: fundamental knowledge to optimize droplet-spread infectious respiratory disease management
https://bmcpulmmed.biomedcentral.com/articles/10.1186/1471-2466-12-11
Quantity and Size Distribution of Cough-Generated Aerosol Particles Produced by Influenza Patients During and After Illness
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4676262/
2. A cluster randomised trial of cloth masks compared with medical masks in healthcare workers
https://www.researchgate.net/publication/275360639_A_cluster_randomised_trial_of_cloth_masks_compared_with_medical_masks_in_healthcare_workers
Testing the efficacy of homemade masks: would they protect in an influenza pandemic?
https://www.ncbi.nlm.nih.gov/pubmed/24229526
3. Beneficial cardiovascular effects of reducing exposure to particulate air pollution with a simple facemask
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2662779/