Indoor Air Quality Services

Modern systems must be designed and operated to achieve a proper balance between air quality, thermal comfort and energy consumption. In healthcare premises, ventilation is used extensively in all types of facilities to provide a safe and comfortable environment for patients and staff. Specialised ventilation is provided in primary patient treatment areas such as operating departments, critical care units and in sterile services departments and pharmacies to ensure compliance with quality assurance.

If ventilation systems do not achieve and maintain the required standards there is an increased health risk to patients. Indeed the link between surgical site infection and theatre air quality has been well established. UCV systems are designed to provide a zone around the patient that is effectively free of bacteria-carrying airborne particles during an operation.

Ventilation systems in healthcare premises are becoming increasingly sophisticated. Patients and employees have a right to expect that these systems will be designed, installed, operated and maintained to standards that ensure it will adequately and satisfactorily fulfil its desired functions.

The Health Technical Memorandum (HTM) 03-01 – “Specialised ventilation in healthcare premises” has been produced to supersede all previous versions of HTM 2025 – “Ventilation in healthcare premises”.

Key issues HTM03-01 addresses include:

• The Verification testing of Critical Ventilation Systems, including pre 2007/8 theatres.
• The Validation testing of New Build conventional and ultra-clean ventilation (UCV) systems.
• The prevention and control of healthcare related infections.
• Layout of minimum requirements for the design of air handling units (AHU) with regard to safe access for routine inspection and maintenance and the control of Legionella.
• Controlling exposure to harmful organisms, toxic and anaesthetic substances.

The objective of the verification processes is to establish that the critical ventilation systems, as defined by HTM03-01, remain fit for purpose and are achieving an adequate operating capacity by satisfying the following criteria:

• The AHU conforms to minimum standards;
• The fire containment has not been breached;
• The general condition of the ventilation system is adequate;
• The fabric of the area served is satisfactory;
• The system performance is adequate with respect to the functional requirement:

a) The measurement of room temperatures and relative humidity;
b) A full measure of the supply and extract air flow rates;
c) The calculation of room air-change rates if applicable;
d) The measurement of room differential pressures if applicable;
e) The measurement of room noise levels;
f) Air-quality checks if appropriate;
g) A check on control functions.

In order to ensure the complete system operates correctly and achieves design requirements, it will be necessary to validate the system as a whole from the air intake through to the extract discharge.

We can provide the following services to ensure compliance with HTM03-01 and hence validate the suitability and performance of an UCV suite.

1. Conventional Theatre Standards

• Supply AHU will have achieved the minimum standard
• Operation of Fire Dampers will have been proved
• Supply & Extract Flow rates will have achieved their design values
• Room temperature, humidity & differential pressures will be correct

2. Challenge tests:

• The UCV terminal is correctly assembled and sealed;
• The terminal filters are correctly sealed in their housings;
• The terminal filters are of the same grade, of uniform quality and undamaged.

3. Air velocity measurements:

• A sufficient quantity of air is being delivered to the terminal;
• The terminal quadrants are in balance;
• The air flow has sufficient velocity to reach the working plane.

4. An entrainment test:

• Outside contaminants are not drawn into the UCV terminal.

5. Visualisation techniques:

• Establish an understanding of overall system performance.

6. Noise measurement:

• Working conditions are satisfactory.

7. Control systems checks

• The system operates as specified.

8. Biological monitoring:

• Determine the effectiveness of the system in use.

In many work activities, substances that are hazardous to health are handled, produced, or processed in ways that results in dust, fumes or gases being given off to the workplace atmosphere. Local Exhaust Ventilation (LEV) has an important place in the hierarchy of control measures, if properly applied. The aim of thorough LEV testing and examination is to provide an independent assessment ensuring hazard control and engineering performance.

Many people today are exposed to a variety of substances at work for example chemicals, fumes, dusts, fibres which can under certain circumstances, have a harmful effect on their health. These ‘hazardous substances’ can cause harm by too much being taken into the body through breathing, by being absorbed through the skin or swallowed, or by acting directly on the body at the point of contract. The Health and Safety Authority have set occupational exposure limits for a large number of hazardous substances at work.

Many work activities involve hazardous substances being handled, produced or processed in ways that result in dust, fumes or gases being given off to the workplace atmosphere. Current legislation requires that exposure to hazardous substances is either prevented or adequately controlled. Local exhaust ventilation is a key part of providing effective means of controlling exposure.

Current regulations require systems to be maintained in an efficient state, in an efficient working order and in good repair. All plant deteriorates with time therefore regular monitoring and testing forms an important part of the proactive maintenance.

Many products and processes require the control of airborne contamination during manufacturing and processing include aerospace, food & drink, healthcare, medical devices, microelectronics, pharmaceutical, biotechnology and automotive industries.

Controlled environments require continuous testing, monitoring and routine re-qualification to ensure compliance with the controlled low levels of environmental pollutants such as dust, airborne microbes, aerosol particles and chemical vapours, sometimes using separate devices such as Clean Airhoods, Gloveboxes, Isolators and mini environments.

Some HVAC systems also control temperature, pressure and humidity using ionizers to prevent electrostatic discharge problems. All these systems require routine re-qualification, testing and monitoring to provide evidence of continual compliance with the legislation.

Our services include:

• Particle count test
• Airflow volume and airflow velocity test
• Room air change rate calculation
• Air pressure difference test
• Installed filter system leak test
• Recovery test
• Airflow visualization test
• Containment test
• Temperature and relative humidity test
• Noise level test
• Lighting level test
• System rebalancing
• Glove box verification
• Hepa filter replacement
• Inspection, Repair and Maintenance Services for:
• Fume Cupboards (Including Radiochemical)
• Microbiological safety cabinets classes I, II and III
• Laminar flow hood / units
• LEV/fumehood verification
• Dust Extraction

Under regulations there is a statutory requirement to undertake formal examinations and testing of LEV systems annually, although under certain conditions these tests must be performed more regularly.

HSA Local Exhaust Ventilation (LEV) Guidance suggests that these checks should be undertake by competent people who are not normally responsible for the system maintenance to get an independent opinion.

Our testing protocols are designed to ensure that the systems are operating effectively and efficiently and comply with the current legislation on LEV systems.

The assessments are all undertaken in accordance with the procedures detailed in HSG 258 “Controlling airborne contaminants at work: A guide to local exhaust ventilation”

The performance of each system is verified using a combination of visual and physical checks of each system including all associated ductwork, filtration equipment and pressure gauges. A variety of test equipment is used where appropriate, including pitot tubes, micro-manometers, hot ball anemometers and other test equipment, to monitor;

• Face velocity
• Static pressure at selected locations throughout the system
• Duct dimensions
• Installation of test points in duct
• Capture distance

Nosocomial (i.e. hospital acquired) outbreaks of aspergillosis have become a well-recognised complication of construction, demolition or renovation work in or near hospital wards in which immunosuppressed patients are located.

What is Aspergillus?

Aspergillus is a fungus or fungal mould whose spores are present in the air we breathe, but does not normally cause illness. However an individual with a weakened immune status may be susceptible to aspergillus infection for which there is a high mortality rate.

Aspergillosis is a group of diseases which can result from aspergillus infection which may affect patients whose immune system may be compromised – including those with leukaemia, chemotherapy patients or those on steroids, transplant patients, cystic fibrosis, HIV or AIDS, chronic obstructive pulmonary disease (COPD), chronic granulomatous disease (CGD), severe asthma with fungal sensitivity (SAFS) and many others.

The risk factors

Sources of increased risk include dirty air conditioning units, compost heaps and damp or flood-damaged housing, all of which can yield higher numbers of aspergillus spores.

Prevention of transmission of Aspergillus Spores

It is essential to maintain air-handling systems in HDU/ICU and other high-risk patient-care areas according to the published recommendations.

The guidelines also require you to develop a water-damage response plan for immediate execution when water leaks, spills, and moisture accumulation occur to prevent fungal growth in the areas where immuno-compromised patients are located; as well as implementing specialist procedures for daily cleaning and routine maintenance, to ensure that spores are not spread.

These guidelines also focus on the protection of patients during high risk periods such as construction/renovation of hospitals. During construction, the dust generated must be minimised and the adjacent patient areas must be protected against the dust. Guidelines call for the systematic review and coordination of infection-control strategies with personnel in charge of the facility’s engineering, maintenance, central supply and distribution, and catering services.

Specifically, when planning construction, demolition, and renovation activities in and around the facility, assess whether patients at high-risk for aspergillosis are likely to be exposed to high ambient-air spore counts of Aspergillus spp. from sites, and if so, undertake a risk assessment and develop a plan to prevent such exposures.

Specialist Sampling Services

Eirdata can provide the following service based on the National Disease Surveillance Centre “National Guidelines for the Prevention of Nosocomial Invasive Aspergillosis During Construction/Renovation Activities”

• Our technically competent personnel will visit site with an air sampler and Agar plates
• Sample areas as specified by client
• Send the plates to the laboratory for incubation and enumeration
• Present the report to the client electronically
• Site visits can be determined by the client and can be either planned in advance for the time-frame of the project or as one-off site visits