Respiratory Protection

 

The importance of clean air


We hardly ever think about having to breathe. It’s so important to life that the process happens automatically.

But because it happens subconsciously it’s easy to underestimate just how important respiratory protection is.

The typical adult takes around 20,000 breaths in a day, which means about 11 cubic metres of air pass through your lungs each day. Imagine the effect on the body if that air is even slightly dirty.

When you breathe in, air passes into the trachea (windpipe). The trachea divides into bronchial tubes that supply the lungs and these divide further into narrower and narrower branches. The smallest airways end in tiny spongy air sacs called alveoli, of which your lungs have over 300 million.

The alveoli are closely surrounded by tiny blood vessels called capillaries. Here the lung carries out its work of exchanging carbon dioxide and oxygenating the blood. The total surface area of the alveoli is amazingly large, estimates vary from 50 to 75 square metres, or roughly the same area as one side of a tennis court.

Dirty air can trigger asthma and respiratory illness. It creates a risk factor for developing lung diseases and provokes development or progression of chronic illnesses including lung cancer, chronic obstructive pulmonary disease (COPD), and emphysema.

When dirty air is breathed in, air pollutants (dust, soot, smoke, chemical toxins) are drawn deep into the lungs. If the pollutant is a dust or mist the particle can lodge in the lungs, in some cases, as with forms of asbestos, permanently. If the pollutant is a toxic gas or vapour it can be transferred through the lung into the bloodstream, where can damage the brain or internal organs.

 

BREATHE EASY WITH ESKO RESPIRATORY GEAR

 

Not all airborne hazards are the same! That’s why there is a range of ESKO respirators and masks to choose from.

Respiratory hazards are abundant on many job sites—smoke, gases, paint and chemical sprays, welding fumes, dust from grinding and sawing. There are six types of airborne hazards:

ESKO offers a range of masks, both disposable and reusable, to protect against these different hazards. Particulate filters are designed to filter dust, mist and fumes, and absorbent cartridges are available to protect against gas or vapour hazards.

Absorbent gas/vapour cartridges on ESKO reusable masks can also be combined with particulate prefilters. The higher the level of risk, the higher the protection should be.

 

Meeting the standards, staying safe

 

To protect themselves as well as their workers, employers should sure they have a written respiratory protection program that includes an annual fit test. Keeping this document up-to-date will ensure the workplace stays safe and in line with regulations.

Worksafe NZ’s A Guide to Respiratory Protection says:

Supplying respiratory protection alone does not necessarily protect the worker. For effective and adequate protection, a specific respirator programme should be put in place. A proper hazard control strategy should be established with the primary aim of preventing exposure to contaminants. The Health and Safety in Employment Act 1992 requires employers to minimise the likelihood of a hazard causing harm to employees.

Where feasible, exposure to contaminants should be eliminated by engineering controls. Only when effective engineering controls are not practicable should the use of personal protection be considered.

The Australian/New Zealand Standard AS/NZS 1715:1994 (Selection, Use and Maintenance of Respiratory Protective Devices) provides comprehensive guidance to employers on providing respiratory protection in the workplace.

 

What Standards does ESKO respiratory protection meet?


All our hearing protectors are tested and certified to meet AS/NZS1716:2012: Respiratory Protective Devices. This Standard sets out the specific requirements for respiratory protection to protect the user
against respiratory hazards in the workplace. Look for these symbols which indicate the product has been passed by an approved testing agency:

 

CHOOSing THE CORRECT FILTER FOR PARTICULATE HAZARDS

 

The AS/NZS1716 classification system rates respirator filters for particulate hazards into three classes: P1 (for particles generated by mechanical processes, eg grinding, sanding, mining), P2 (for particles generated by mechanical and thermal processes, eg welding, metallic fumes and P3 (for highly toxic particles, eg organophosphate insecticides, radionuclides [the filter is required to be used with a full facepiece]). The AS/NZS1716 standard also provides a rating system for gas and vapour cartridge filters according to the gas/vapour hazard, and according to the cartridge’s absorption capacity.

 

 A GUIDE TO THE AS/NZS1716 CLASSIFICATION SYSTEM FOR GAS AND VAPOUR CARTRIDGE FILTERS 

CLASSIFICATION

EFFECTIVE AGAINST

TYPICAL USES

P1

Suitable for relatively large particles (>1 micron) generated by mechanical processes, eg. grinding, sanding, drilling, sawing, mining. Filters at least 80% of airborne particles.

General, not highly hazardous, dust from timber, MDF, masonry, plasterboard, concrete, plaster, brick, stone, painted surfaces; roof and tile dust, metallic dusts; glass, rock wool & mineral wool fibres, large paint particles, pollen, hay, feathers, animal feed dust, spores

P2

In addition to the above, particles generated by mechanical and thermal processes. This class of filters has a higher capture efficiency to deal effectively with smaller, thermally generated particles like sub-micron sized welding fumes or fertiliser. P2 filters can also capture biologically active airborne particles under specified conditions and are recommended for specific infection control applications (e.g. SARS, TB or other infectious diseases). Filters at least 94% of airborne particles.

 

Fine dust, higher concentrations of dust, welding and metal fumes; low level non-restricted asbestos work, low level water & oil based mists

P3

In addition to the above, highly toxic particles, eg. organophosphate insecticides, radionuclides, asbestos (the filter is required to be used with a full facepiece). Filters at least 99.95% of airborne particles.

For use with toxic materials and/or when very high protection levels are needed

 

PARTICULATE FILTERS SHOULD BE REPLACED WHEN THE FILTER BECOMES DIRTY, TORN OR CLOGGED 

(THE USER CANNOT BREATHE EASILY THROUGH THE FILTER)

 

CHOOSing THE CORRECT ABSORBTION CARTRIDGE FOR GAS/VAPOUR HAZARDS

 

A guide to the AS/NZS1716 classification system for gas and vapour cartridge filters

 Classification 

AS/NZS colour coding

EFFECTIVE AGAINST

A

Brown

Organic vapours, boiling point > 65°C (eg. hydrocarbon or alcohol vapours from paint, solvents, fuel, adhesives)

B

Grey

Inorganic gases (eg. carbon monoxide, chlorine, sulphur dioxide)

E

 

Acid gases and vapours (eg. sulphuric acid, sulphur dioxide, hydrogen chloride, hydrogen sulphide)

K

Green

Ammonia, methylamine

ABEK

Brown/Grey/Yellow/Green

Combination gases (all of the above)

Hg

Red

Mercury

ABSORPTION CAPACITY

Efective against

1

Low to medium absorption capacity. Maximum gas/vapour concentration 1,000 ppm.

2

Medium absorption capacity. Max gas/vapour concentration 5,000 ppm.

3

High absorption capacity.

 

When should I change my disposable mask?

 

Disposable masks are designed to last for a maximum of an eight-hour shift, however, in hot, dusty, humid conditions, or where the wearer is removing or adjusting the mask frequently, the effective life of the mask will be much reduced. REPLACE THE RESPIRATOR WITH A NEW ONE IF:

  • The respirator is removed in a contaminated area;
  • Excessive clogging of the respirator causes breathing difficulty;
  • The respirator becomes damaged;

A mask should fit snugly for the entire shift. If not, the mask should be replaced, and the old one disposed of.

 

Why choose an exhalation valve?

 

An efficient exhalation valve makes breathing easier and minimises heat and moisture build up, particularly in hot and humid conditions.

 

Why activated carbon?

 

Layers of activated carbon incorporated in ESKO PC531 and PC823 Welding Speciality Respirators are designed to offer relief from the irritation of low levels of ozone, fumes, nuisance odours and vapours especially from  paint or welding.

 

How LONG WILL A GAS/VAPOUR CARTIDGE LAST?

 

The expected service life of any gas and vapour cartrige is affected by factors including contaminant concentration, the breathing rate of the user, the humidity level, temperature, desorption and storage conditions. Kept in their original sealed wrappers cartridges will last two years from date of manufacture.

Gas and vapour cartridges use activated carbon absorbent material to absorb molecules of contaminant gases. When the absorbent capacity of the cartridge is exceeded the user will usually notice gases or vapours coming through the cartridge. This is called the ‘breakthrough time’.  In use, cartridges should be replaced:

  1. In accordance with the company’s change schedule,
  2. After the cartridge’s expiration date,
  3. At least after six months service, according to the AS/NZS recommendation,
  4. At any time if contaminant can be smelled or tasted inside the mask or if any irritation is detected.

A safety factor should be applied to ensure that the breakthrough time of cartridges is not exceeded—note that some gases do not have an odour and cannot be detected by smell. If the contaminant is hazardous at low concentrations the worker may already have been exposed to harmful levels by the time any odour is detected.

Assess the factors applying to your particular application and develop a documented schedule for replacing cartridges. Record the date cartridges are put into service and their required replacement date, note this in writing on the cartridge. Adjust the schedule if usage factors change or if the breakthrough time of cartridges is being exceeded.

 

More information:

 

This information is provided as general advice and is not intended to apply to severe hazards such as highly toxic chemicals, isocyanates, radionuclides, asbestos, or in oxygen deficient atmospheres. Specific situations, concentrations and toxicity of hazards can vary greatly. For advice with particular chemical hazards, refer to the manufacturer’s Safety Data Sheets (SDS). For other helpful information refer to:
Worksafe NZ’s guide to respiratory protection


Relevant standards:

  • AS/NZS 1715:1994: Selection, Use and Maintenance of Respiratory Protective Devices
  • AS/NZS 1716:2012: Respiratory Protective Devices 
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