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150 Years of Howorth Air Technology

1 July 2008

Happy Anniversary, Howorth Air Technology. 

Apart from provoking the inevitable initial response, “Has is really been that long?” an anniversary can also make you look back and reflect on what has happened and how things have changed. 150 years ago, for example, Charles Darwin made one of the most significant breakthroughs in scientific history – his theory of natural selection, which provoked an outraged response from many of his contemporaries who considered his views radical to the extreme. Now his face is on the ten pound note.

In July 2008, the NHS celebrated its 60th anniversary. The changes in medical care during its lifetime almost defy belief; many of the standards we now take for granted were once seen as revolutionary. For example, in 1948, the year the NHS was founded, a cataract operation meant a week of total immobility with the patient’s head supported by sandbags. Eye surgery is now over within 20 minutes and most patients are out of hospital the same day.

Working in the medical field, Howorth Air Technology has been producing the Exflow Ultra Clean Ventilation Unit since 1976. However, the company’s history, and the experience which would later lead to the production of the Exflow, goes back a lot further, and in 2008 it celebrated its Anniversary, too – 150 years in the “clean air industry”.

As befitting a Lancashire company founded in Rochdale and operating to this day from Bolton, it all started with the mills. The air in the mills had to be kept hot and humid to prevent the thread breaking; rooms were poorly ventilated and the air was often thick with cotton dust. In 1858, Rochdale man James Howorth set up James Howorth & Co Ltd, manufacturing apparatus for humidifying, ventilating, heating, air-conveying, dust control and drying applications within the textile industry.

In 1861, the Lancashire cotton industry employed 446 000 people – 18.3% of the area’s entire working population. 

By the 1900s, the firm was specializing primarily in producing air conditioning and humidifying equipment. Then, in the late 1950s, another Lancashire man, Sir John Charnley, the world-renowned orthopaedic surgeon, recognised the necessity of providing an aero-microbiologically clean zone during surgery to avoid wound sepsis from airborne contamination. He commissioned Howorth to design what was to become the world’s first ultra clean air surgical enclosure. It was installed at Wrightington Hospital with a dramatic reduction in infection rates.

There was a major development in the company in 1976, when Howorth patented its pioneering Exflow Ultra Clean Ventilation system, which generates an ultra clean zone, free from peripheral entrainment without the restriction of side walls.

Ultra Clean surgery is now considered the norm for orthopaedic operations and is increasingly being used for other operations in which there may be a risk of infection from airborne organisms.


In the late 1990s, the growth in demand for protection from potent materials and chemical hazards prompted the launch of a dedicated containment division, designing, manufacturing and supplying bespoke containment equipment to ensure product purity and safeguard operators from the hazardous materials used in the production and research of pharmaceuticals and fine chemicals. The division has now grown to join the medical division at the forefront of its field.

As a company, and with a new management team at the helm, Howorth Air Technology continues to advance, with 2008 seeing the launch of a new USA facility in Louisville, Kentucky, which will produce an Exflow designed specifically for the US market. Back in Bolton, there is a new product test facility and a showroom featuring a fully fitted twin operating theatre, complete with working UCV systems, which allows clinicians and hospital personnel to visit and experience and evaluate equipment. Westbury Filtermation Ltd has also joined the Howorth Air Technology Group, meaning the company can further enhance its service offering to include full air handling unit servicing together with filter replacement, inspection, deep cleaning and sterilisation.

The Exflow Ultra Clean Ventilation system continues to be a world leader in providing ultra clean conditions for surgery, and enabling an increasing number and variety of operations to be carried out with a greatly reduced risk of post-operative infection. What started in the mills has developed into a vital and familiar element of the modern operating theatre, produced by a company still based in the town that saw the idea’s inception 150 years ago. This is certainly an anniversary worth celebrating.


More than 30 years after its development, the Exflow has been installed in over 2,000 operating theatres worldwide.