Infection control protocols for industrial hearing screening

Testing off-site

Infection control guidelines are usually clearly outlined in hearing clinics, but when you are required to test off-site as with industrial hearing screening, infection control procedures will be different and restricted to the resources you have access to. For example, running water may not be available for the normal hand washing technique, so you will have to be prepared for this eventuality.

Care for self

As a clinician working off-site you must take care to eliminate the risk of disease transference. One of the most important (and easiest way) to reduce this risk is to follow correct hand washing procedures. A good reference document is available from the Australian Government Department of Health and Aging called Infection Control Guidelines. You may have already had a look at it.

Infection Control Guidelines - Go to section 12: Hand washing and personal hygiene.
One of the important ways of infection control we have discovered in the last century or so is also one of the simplest — hand washing. The next step is drying them carefully.
Try this exercise. (If you have kids, they might like to do this with you). Get a big spoonful of Vegemite, non-toxic paint or something of a similar consistency, and rub it all over your hands so that all the skin is covered. Now wash it off. Take notice of the last places the Vegemite clings to — these are the areas you will have to pay most attention to in your hand washing at work.
Hand washing is the single most important procedure for preventing transmission of infection.

When to wash your hands

It is essential that you wash your hands after touching blood, body substances and contaminated items—even if you had been wearing gloves when touching them
You must also wash your hands:
• at the beginning and end of each work shift
• before and after physical contact with a client
• after handling contaminated items, such as otoscope specula and tympanometry tips, and items of waste
• before you put on gloves
• after gloves are removed
• between client contacts
• at the beginning and end of each meal break
• before and after going to the toilet
• before and after handling food
• between some tasks and procedures performed for the same client to prevent cross-contamination of different body sites eg from one infected ear to the other non-infected ear.
• after blowing your nose or covering a sneeze
• whenever hands become obviously soiled.
If in doubt about the need to wash your hands, wash them anyway.

Where to wash your hands

Hand washing should be carried out at designated hand washing basins only. Preferably, these basins should have no touch taps (operated by sensor, foot, elbow), liquid soap and disposable or single use paper towelling. When testing off site you will need to investigate what basin is available before you begin your testing session. Hand washing basins should not be used for any other purpose.

What to wash your hands with

Clean running water and liquid soap or antiseptic are the preferred items for hand washing. If unavailable, using non-water cleansers such as foams and alcohol based rubs are acceptable. Hands should be wet and then the cleaning agent added. It is important to use an acceptable liquid soap and warm water. Some hand washes contain Chlorhexidine or Hibitane. These agents help to inhibit the growth of micro-organisms on the skin and break down debris and oils in which micro-organisms are harboured. They can also be quite harsh on your skin with repeated use so it is very important for you to follow up with the use of suitable hand moisturiser.

Hand washing procedures

We have already stated that hand washing is the single most important procedure for preventing the transmission of disease. Understanding the importance of hand washing is probably one of the easiest concepts to grasp, although sometimes we tend to underestimate its significance and that is what makes it so important.
You may be saying to yourself, “I know how to wash my hands and I know how important it is”. However, to ensure no step is missed, you should look at the following diagrams which explain hand washing techniques.
We will now look at a hand washing technique that is relevant to hearing services staff. Below are two explanations for the same technique. Both explanations are of the same technique but you might prefer one over the other.
Explanation 1
Here is an explanation of the steps involved in hand washing. Some clinics place this as a poster near their hand washing basins.
Remember to repeat procedure for 10 seconds.

Explanation 2


After washing your hands

Rinse your hands After washing, hands are to be rinsed thoroughly from fingertips to wrist. Remember when turning off the tap not to contaminate your clean hands. If ‘no-touch’ taps are unavailable, then turn off the taps using a paper towel to cover taps. Dry your hands Careful drying is as important as careful washing in preventing cross- infection. Dry hands thoroughly with paper towelling.

Personal protective equipment

Working off site you must also be aware of any personal protective equipment you will be required to use to minimise the spread of infection. Personal protection is a major step in the prevention of cross infection as well as injuries. The wearing of masks, eye protection, gloves, aprons and shoes is routine while working in the clinic but may or may not be required when testing off site.
If you have access to the following standard relating to PPE, familiarise yourself with it:
HB 9-1994: Occupational personal protection, Second edition 1994.
It may be available in your workplace or at a TAFE library.

You can read about the scope of this standard at:

Personal protective items include:
• masks or face shields
• eyewear / face shields
• gloves (appropriate to the task)
• hearing protection
• uniforms
• shoes (covered)
• gowns or fluid resistance aprons where required.
When testing off site it is unlikely that you will require much in the way of PPE, however each work site you attend may have certain regulations that you will need to adhere to. For example, some worksites may require long sleeved shirts and long pants to be worn at all times. Steel-capped boots may be required in certain industries. You may also be asked to wear a hard hat and/or hearing protection if moving around the work site moving between noisy areas.


Gloves may be required while testing off site. Gloves are worn as a barrier. They protect you from contamination and protect others from the transfer of any micro-organisms already on your hands. Gloves are to be worn whenever you undertake a procedure that may potentially expose you to blood or body substances (except sweat). Gloves are single use items and must not be reused. Gloves should be replaced as soon as possible if damaged, punctured, or torn. No attempt should be made to wash, rinse, or re-use gloves.
Note: Gloves are not a substitute for hand washing! Hands should be washed before and after using gloves.
Gloves come in a variety of sizes and may be made of latex, neoprene, or vinyl. While most manufacturers are producing powder free gloves, some gloves are pre-packed with a light inner-coating of powder to assist in the gloving process. Many workplaces will provide a selection of gloves for different purposes and it is essential that you become familiar with the type of gloves you are required to wear for specific procedures.
Non-sterile gloves — used for any procedure where there is a risk of hands being exposed to blood or other body fluid such as fluid from a discharging ear, or come in contact with mucous membranes.
Sterile gloves — used for procedures requiring a sterile field
General purpose utility gloves — for cleaning of instruments, equipment and toys prior to sterilisation or disinfection, or for general cleaning procedures.

Note – Latex allergy
A large range of equipment used in the community services and health industries contains latex, including some (but not all) types of gloves. Due to the increasing prevalence of latex allergy in the community, it is recommended that non-latex and powder-free gloves should be used where possible. If you develop any symptoms of latex allergy you should avoid any further contact with latex-based products, notify your supervisor and seek consultation with your family doctor or a physician who specialises in latex allergy.
For more information see the NSW Health Department publication Latex Allergy — Policy Framework and Guidelines for Prevention and Management, doc no. PD2005_490, 25 February 2005 at:

Gloves used on a client must never be worn:
• when writing up notes
• leaving the clinic
• in reception area
• answering the telephone
• waiting room areas
• in common tea rooms.

Nails are to be clean and should be kept to an acceptable length to prevent the gloves being damaged. Gloves should be removed carefully to avoid contamination of hands or other surfaces.

To take gloves off properly:
1 Do not touch the outside of the gloves with your hands.
2 Gently pull off one glove by the fingers using your other gloved hand.
3 Slide the fingers of your now bare hand under the wrist of the other glove.
4 This will push off the second glove without touching the outside surface.
5 Dispose of immediately.
6 Wash hands.

Uniforms and outer protective clothing

Uniforms if supplied should be comfortable and suitable for the type of procedures being carried out in your clinic. Gowns or plastic aprons prevent clothes and the skin coming into contact with body fluids when cleaning up spills or when doing general cleaning.
For clinical practice, regardless of what is personally worn (street clothes/uniform), outer protective clothing should be worn when undertaking procedures that involve the likelihood of body fluid contamination. The outer protective garment should be fluid resistant.
The use of these types of barriers prevents transmission of disease via direct contact.
Change protective clothing and gowns/aprons daily—or more frequently if soiled and where appropriate.


Shoes must cover the entire foot. This protects any area of the foot being damaged by falling equipment or other objects or any type of spill.

Care for client

Quite often we may only think of major infectious diseases as being of concern to the hearing assessment team. You must remember even the common cold is an infectious disease and may result in members of the staff requiring time off work. The infection can be spread to other staff members and clients. We must consider all clients as being infectious, and this is why standard precautions are followed.
To implement these principles of best practice in infection control each hearing clinic should have an infection control manual that has been designed for the education of all staff in the policies/procedures/protocol that are to be followed. It is also important that an infection control manual be implemented for assessing hearing off-site. The following areas should be detailed in the manual:
• methods of hand washing
• personal protective equipment requirements
• preparation for a client
• clean up procedures between clients
• processing of reusable items — cleaning, packaging, sterilisation or disinfection and storage.

When conducting hearing screening for industrial hearing loss you may also need to consider the following, (but keep in mind, the site where you are testing may have their own procedures for management of waste and body fluid spills so ensure you liaise with the appropriate OHS officer before beginning your clinic):
• defined areas of contamination
• management of blood or body fluid spills
• handling and disposal of sharps
• waste disposal
• management of body/body fluid exposure.

Cross infection?

Hearing clinics run off-site have a variety of areas where contamination and cross infection occur.
Cross infection involves coming into contact with a contaminated surface, instrument, or substance. Diseases may be indirectly transmitted by the micro-organisms that are present on the item that has been touched.
Of particular concern is the situation where cleaning of an instrument used on one client has not been carried out and that instrument is then used on another client. The micro-organisms could then be transferred from one client to another.
Diseases may be indirectly transmitted by dirty hands, towels and instruments - even dust. Other common areas of infection in the hearing clinic may include tap handles, switches, drawer handles, client charts, even the pen used to write on the client’s chart
Let's look at some specific areas and items of concern for the off-site hearing clinic.

Assessment area

When testing off-site, you could be testing in the First Aid room, allocated audiometric booth or quiet office. Check the room is clean before you start, taking particular care of audiometry equipment including otoscopes, desks and furniture, telephone handsets, computer screens and keyboards, pens and client charts/files. If you are concerned about the cleanliness of the room, check with the OHS officer on site to see if more appropriate testing facilities can be found. Obviously the ambient noise level of the room is of high priority but you do not want the clients sitting in unclean surroundings which may make them uncomfortable. Ensure you audiometric equipment is clean. Apart from the audiometer, the headphones, insert earphone, bone conductor, patient response button all come into bodily contact with many people. There may be other items of audiometric equipment, otoscope and specula, tympanometer and ear tips, assorted clean and contaminated jars. Ensure you have a well defined procedure in keeping all portable equipment clean.


Check if there is a sink in the testing area that can be specifically designated for hand washing. If not, use a hand washing preparation that does not require water.
Hands should not be washed in a sink which is used for either instrument cleaning, or disposal of blood, body substances or chemicals or the sink in the staff room which is used in food preparation.

Workers' role in infection control

The client also has a role in the preventing of cross infection when having their hearing assessed.
The client should inform you of any infectious diseases they may have presently or have had in the past. You may become aware of this information during the case history interview. The client may not be aware they have an infectious disease and this is why we must treat all clients as if they are infectious and follow standard precautions.
NSW Health has endorsed a two-tiered approach to infection control.
1 Standard precautions. The first and most important approach to infection control is the application of standard precautions to the care of all clients regardless of their diagnosis, disease status, or presumed infectious status. Standard precautions are the minimum acceptable level of infection control practices, and must be followed by all employees in all health and community care services.
2 Transmission-based precautions. The second level requires that additional precautions and practices are applied to the care of clients who are known, or suspected, to be infected with diseases that are spread by airborne or droplet transmission, or contact with dry skin, or contaminated surfaces, or by any combination of these routes.

Standard precautions

Standard precautions are work practices required for the basic level of infection control. They include:
• good hygiene practices, particularly washing and drying hands before and after client contact
• the use of protective barriers which may include gloves, gowns, aprons, masks or shields
• proper handling of sharps
• use of aseptic techniques — ie cleaning, disinfecting and sterilisation.

Standard precautions apply to:
• blood
• all bodily substances, secretions and excretions except sweat, regardless of whether or not they are known to contain visible blood (ie tears, phlegm, urine, saliva, faeces, vomit etc)
• non-intact skin (eg cuts, sores, wounds)
• mucous membranes (eg mouth, nose, eyes, anus, vagina).

Standard precautions are recommended for the treatment of ALL patients, regardless of their infectious status.
Transmission of infection is possible from clients to hearing screening personnel and vice versa by a number of pathways in a testing environment. Risk of cross infection should be minimised through careful work habits and these must be adhered to when testing off-site, no matter where the testing may be taking place.

Micro-organisms and viruses are not able to travel from one person to another or from one object to another on their own. They need a means of transportation, such as:
• people
• air, dust, food, water
• inanimate objects (eg instruments, clothing)
• insects and vermin.

Organisms can be transmitted from a source by four main modes:
• direct contact
• indirect contact
• vectors
• placenta.

Direct contact
By direct contact we mean direct physical contact between one person and another, such as:
• touching with hands, which is probably the most common way of transmitting pathogenic organisms from one place to another
• kissing or sexual activity.

Indirect contact
Transmission of organisms by indirect contact can occur by contact with:
• fabrics (eg. handkerchiefs, clothing)
• used instruments and other appliances
• food, water and air
• insects and vermin.

Airborne infection
Airborne infections are caused by pathogenic organisms carried through the air by dust or droplets. Minute droplets containing organisms are projected from the mouth and nose for 1m to 2m through the air whenever a person speaks, coughs or sneezes. Large droplets may directly infect the nose, throat, eyes or a wound of a person close by. Alternatively, these droplets may fall on personal clothing, toys, and furniture (such as equipment table, which in turn contaminates specula and tips). Small droplets may evaporate, leaving in the air suspended infected particles, known as droplet nuclei, which can be carried a considerable distance.

Vectors are animals or insects that carry pathogenic organisms from one host to another. For instance, flies commonly transfer gastrointestinal organisms from excreta to food.
So, you must bear in mind that every item in your testing environment, which is not sterile and protected, has living organisms on it. Some of these organisms may be pathogenic. This contamination can be caused by settling of infected dust, contact with clothing, or direct contact with infected body secretions like ear discharges.
Some insects cause infections by depositing organisms on the skin surrounding bites. Scratching the site pushes the organisms into the bites. Insects such as mosquitos actually suck up organisms from an infected person and inject them into another person.

Some pathogens are able to enter the foetal circulation from the mother via the placental blood vessels, for example, AIDS, cytolomegalovirus (CMV), rubella.
Now that you have an understanding of how infectious diseases can be transmitted it is time to think about what you can do to avoid the spread of infection when conducting screening hearing tests for industrial hearing loss.

Care for equipment

Cleaning audiometric equipment — manual cleaning
Cleaning the audiometer and otoscope and other equipment can usually be carried out at the testing site. It is always advisable to use disposable speculum when testing off-site as proper sterilisation procedures will probably not be available until you return to the hearing clinic.

Transport to cleaning area
Soiled instruments should be transferred to the cleaning area safely and in puncture resistant and leak resistant containers or trolleys. These should have a lid or liner that can be closed.
All equipment used on a client should be cleaned no matter whether it is then to undergo disinfection or sterilisation. It is important to remember that an item that has not been cleaned thoroughly cannot be disinfected or sterilised.
The degree of processing required for items can be established by Spaulding’s classification which has been adopted by NSW Health and documented in Infection Control Policy 2002/45. There are three categories within the classification and they are:
1. non critical
2. semi critical
3. critical.

Non critical
This classification refers to any item or equipment that comes into contact with intact skin only. These items must be cleaned with detergent and water.

Semi critical
This refers to items that will come into contact with intact non-sterile mucosa or non intact skin. These items require cleaning with detergent and water followed by disinfection or high level disinfection.

Any item that enters or is capable of entering sterile tissue or the vascular system must be cleaned with detergent and water and then subjected to sterilisation.

The cleaning process

The cleaning process depends upon various conditions.
These are:
• surface being cleaned and type of instrument (eg do they have to be dismantled for cleaning?)
• nature and amount of soil (eg blood, bone and tissue fats)
• composition and concentration of detergent
• pH of detergent to be used
• quality of water (eg hardness factor, pH)
• pH of cleaning solution
• mechanical factors (note: most cleaning operations require some measure of physical effort, be it rubbing or scrubbing)
• temperature of cleaning solution.

Whether the cleaning process is being performed manually or mechanically the same basic steps need to be performed.
The steps are outlined below.

Step 1: Pre-rinse
An initial cold pre-rinse will remove the majority of gross soil and, with it, 80 per cent of micro-organisms. The pre-rinse will hopefully be performed soon after use. After the pre-rinse, instruments should not be allowed to fully dry until processed. Items for pre-rinse and steps1 to 4 are otoscope specula, tympanometry tips, inserts.

Step 2: Wash
Water is the universal cleaning agent and an adequate supply of hot water (40˚ to 50˚C) is the strongest weapon against contamination. Although water alone possesses some detergent value, it cannot effectively remove proteinaceous soil, or oil or grease from the surface of instruments and utensils. Adding a suitable detergent to water is most important for effective cleaning. Detergent acts as a wetting agent, or surfactant, and facilitates the exchange of a soiled surface condition for a clean surface plus a soiled detergent.

Step 3: Rinse
A hot rinse will carry away soil entrapped in the detergent. The heat of the rinse helps decontamination and is an aid to subsequent drying. The temperature for a manual hot rinse is between 50˚– 60˚C and for a mechanical hot rinse it should be between 80˚ – 85˚C.

Step 4: Drying
All drying should be done in a mechanical drier. Items should not be dried with towels or left to dry in ambient air. However if a mechanical dryer is unavailable, lint free wipers can be used to wipe instruments as soon as possible after washing.
Points to observe when cleaning manually
Do all the scrubbing underwater so that you do not create aerosols (small particles of water that float in air) which can contaminate you and the surrounding area with infected material. Always wear appropriate PPE such as gloves and protective clothing, mask and/or eye protection. Hand washing is essential before and after the cleaning process.

Drying items following cleaning
Once items have been cleaned they must be dried. If you have no alternative other than hand drying, then you should always use a lint free cloth. Single use absorbent cloths are available and should be discarded following use. Equipment that is left wet can encourage both damage to the item and lead to microbial and other contamination.

Further processing of items
Items that do not require either high level disinfection or sterilisation can, after cleaning, be wiped over with an alcohol preparation of 80% ethyl alcohol or 60-70% isopropyl alcohol. The items must then be dried prior to storage.
Items that can be cleaned in this way on a daily basis include:
• audiometers
• tympanometers
• otoscopes
• laptops

There may be specific manufacturer’s cleaning instructions for you to follow. Cover these items or store them in their case when not in use.
Other items in the clinic require wiping with an alcohol wipe after every use. These items include the audiometer headphones (band and cushions), bone conductor and client response button.
Otoscope specula used on discharging ears should be discarded after use and treated as clinical waste.

Infection control processing of reusable items such as otoscope specula and tympanometry tips should be carried out as soon as possible on return to the clinic. Always use alcohol wipes for cleaning headphones, bone conductor etc after every client while working offsite.