What Are The Grades Of Breathing Air?

In a typical industrial facility, compressed air – also known as Industry’s fourth utility is one of the common facilities used. 

70% of all manufacturing activities are inclusive of compressed air with supplying breathing air to personnel using supplied air respiratory equipment as many industrial operations include Hazardous breathing conditions. 

Industries such as chemical manufacturing, hospitals, abrasive blasting, paint spraying, industrial cleaning, and arc welding are places where you can experience the highest intensity of hazardous breathing conditions.  

To protect the workers of these industries or any other operations that deal with contaminants in the workplace, supplied-air respirators, air filtration systems, and carbon monoxide monitoring systems are used. 

This European Standard specifies requirements for the quality of compressed gas supplied for mixing or use in respiratory protective devices and hyper- and hypobaric operations.

According to BS EN 12021:2014. In summary, BS EN 12021:2014 ( European Standards) sets these limits for breathing air testing: 

→ Oxygen content (v/v) of 19.5% – 23.5%;  

→ Hydrocarbon (condensed) content of 5 milligrams per cubic meter of air or less;

→ Carbon monoxide (CO) content of 10 parts per million (ppm) or less;

→ Carbon dioxide (CO2) content of 1,000 ppm or less; and

→ Lack of noticeable odour”

→ Air Compressor Location Selection

One of the common sources of supplied breathing air is oil-lubricated air compressors. Such compressors are placed in a wide range of ambient air conditions. 

Some of the common contaminants in the air are carbon monoxide, water vapour, oil, and dirt. 

While providing safe compressed breathing air, you  should consider the location of the air compressor. 

Additionally, the HSE asks employers to ensure the construction and suitability of compressors that supply breathing air to respirators to prevent and control the entry of contaminated air into the air supply system.

Generally, the air compressors in a big industrial facility are usually located in a separate and dedicated area from where the actual supplied-air respirators are in use.

It is necessary to locate the compressor away from hazardous zones where the air intake could be easily contaminated. 

One such example is vehicle loading areas where carbon monoxide gets accumulated. Plus, air intake can also easily accumulate where chemicals and solvents are being used and stored or at a place where heaters and combustion equipment are used. 

How Many Types of Compressed Air Contaminants Are There?

There are mainly four types of compressed air contaminants of concern in a compressed breathing air system.  

Here is the list of compressed air contaminants – 

→ Carbon Monoxide –

Carbon monoxide is a common toxic contaminant in compressed air. CO enters the breathing air system through the air intake. It is also produced by overheating piston-type air compressors. 

It is recommended to place engine exhaust or any other source of carbon monoxide away from the air intake. 

The side effects of CO poisoning may lead to headaches, shortness of breath, dizziness, nausea or vomiting, confusion, and loss of consciousness. 

→ Water Vapour –

Air contains moistures, which are drawn into the air compressor and enters the air streams as a vapour. 

As compressed air flows through the system, it cools and condenses, causing the vapour to condense in the facepiece or helmet. 

Moreover, a clog or damage to system components may happen when moisture combines oil and solid contamination to form sludge. 

→ Oil Mist –

Oil is a significant contaminant in systems using lubricated air compressors. 

Lubricant oil is applied to cylinders in reciprocating compressors which causes small droplets by the shearing action of the piston to enter the air system as a mist. 

→ Solids –

Solid usually enters the system through air intake but some materials may enter by the air compressor itself. Fractional wear causes participles to cause particles from these materials to enter the air stream system. 

How does Air Filtration System work?

A compressed air filtration system that removes oil, water, solid particles, and odors from supplied breathing air is a significant component in supplying Grade D breathing air and making sure the safety of workers and employees using compressed air. 

Good quality air filtration systems incorporate a unique three-stage filtration concept that utilizes a prefilter, high-efficiency coalescer filter, and charcoal adsorbed element. 

After that, the compressed air passes through a two-stage filtration system that removes oil, water, and solid particles from the compressed air. 

Two filters of air filtration systems – namely pre filter and coalescer are highly functional as prefilter extends the life of the coalescer and adsorber filter elements while coalescer is a high-efficiency filter that removes oil mist and sub-micron particles. 

After filtering the compressed air is filtered through the prefilters and coalescer, it passes through the adsorber filter which removes unpleasant odour and taste.  

Additionally, the air filtration system manifolds have a maximum capacity of 50 CFM and are equipped with four outlet ports each supplied with a quick disconnect. 

The system provides uniform air distribution to four supplied-air respiratory filters and a fifth quick disconnect can be used for connecting a carbon monoxide monitor or an additional respiratory filter. 

→ Carbon Monoxide Monitoring –

Carbon monoxide monitors are specially designed to monitor CO levels in compressed air.  

Premium carbon monoxide monitoring systems are generally easy to install and operate compressed airline carbon monoxide monitors while meeting the European Standards for monitoring requirements. 

The instruments are designed for trouble-free operation, utilizing a carbon monoxide sensor with a life expectancy of up to three years. 

The system is factory pre-calibrated and users can change alarm points, program relays for auxiliary warning equipment, and perform calibration in the field. Plus, it is also easy to replace the sensor and recalibrate the instrument in the field. 

→ Complying With European Standard Breathing Air

The best solution to protect your workers against exposure to contaminants in supplied breathing air is a system that includes both air filtration and CO monitoring. 

An air filtration panel and carbon monoxide compressed airline monitor combination system complies with European Standards for breathing air. Such systems are mounted directly on the wall or a mounting plate.  

In poor environments, like large amounts of dust, sandblasting material, particulates, hazardous liquids, gas vapors, overspray, and corrosive materials, customers require more protection for instruments. 

Based on the customized requirements to protect the filtration and monitoring, we can mount them in stainless steel, aluminum, or fiberglass enclosure. 

Such enclosures deflect and protect the breathing air filtering and monitoring equipment from hazardous environments, providing continuous long-life operation. Enclosures can be inclusive of a lock and keep an unauthorized person from tampering with the devices. Moreover, connection ports are plumbed on the outside of the enclosure for easy access. 

Additionally, CO monitors can be programmed to activate auxiliary equipment such as a strobe light and horn attached to the outside of the enclosure. With the help of such programming, users can get visual and audible alerts in the work area when a hazardous breathing air condition exists. 

As employers are responsible for providing and maintaining safe breathing air equipment for their employees, an air filtration system and carbon monoxide monitoring systems support employers in meeting OSHA required Grade D breathing air. 

How Orbis Environmental and Safety Can Help You?

We at, Orbis Environmental and Safety, help all types of businesses to be in alliance with the DSEAR and other work-related regulations of the UK. 

Orbis Environmental and Safety provides occupational noise monitoring and much other health and safety services like DSEAR Assessment, Fire Risk Assessment, HAVS Assessment, Noise Risk Assessment, Ergonomics, and manual handling, Workplace exposure monitoring, Legionella, Face Fit Testing, Approved contractors, and Breathing Air Testing. 

We have delivered over 100+ test assessments for many of our clients with the best practice and are competent to deliver consistently high dependable, unbiased and accurate results. 

Fill in the contact form or email us at [email protected], and our team will get in touch with you soon!