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

gary.pharo@srsafety.com

ukhelpdesk@srsafety.com

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/