1: Health and Safety, Occupational Hazards and Infection Control in the Dental Workplace

CHAPTER 1 Health and Safety, Occupational Hazards and Infection Control in the Dental Workplace

Chapter points

• This chapter covers the requirements of the NEBDN syllabus Section 1: Health and safety and infection control in the workplace.
• The chapter is divided into two subchapters:

1.1 Health and Safety and Occupational Hazards

1.1Health and Safety and Occupational Hazards

Health and safety: general considerations

• A hazard is anything that can cause harm. All workplaces, including the dental surgery and especially the laboratory, contain some hazards.
• A risk is the chance of someone actually being harmed by the hazard.

It is essential that dental nurses are aware of the hazards in the dental workplace and the health and safety actions that you can take to avoid harm. Human error is responsible for most risks in a workplace.

Key Point

All dental practices must have in place policies and procedures that guide staff how to respond appropriately when a hazard is anticipated and to reduce risks. Local policies and procedures are based on national health and safety regulations.

In the UK:

• The Health and Safety Executive (HSE) is the government body currently responsible for regulating health and safety in the workplace. All dental surgeries are required to be registered with the HSE.
• The General Dental Council (GDC) also lays down particular regulations for dental staff, which include health and safety with regard to dental workplaces.

Term to Learn

General Dental Council: the body that regulates all dental professionals training and working in the UK.

Key Point

If an employer or employee does not comply with health and safety regulations, they could be prosecuted.

Health and Safety Legislation

Several government Acts and Regulations deal with health and safety in the workplace; these laws and regulations are enforced by the HSE. Of particular importance to the UK dental environment are:

• Control of Substances Hazardous to Health Regulations (COSHH; 1994)
• Environmental Protection Act (1990)
• Fire Precaution (Workplace) Regulations (amended 1999)
• Health and Safety at Work etc. Act (HSW; 1974)
• Health & Safety (First Aid) Regulations (1981)
• Ionising Radiations Regulations and Ionising Radiation (Medical Exposure) Regulations (IRME; 2000; see Chapter 14)
• Reporting of Injuries, Diseases, and Dangerous Occurrences Regulations (RIDDOR; 1995)
• Special Waste & Hazardous Waste Regulations (England and Wales 2005; see Subchapter 1.2).

As a dental nurse, you need to be aware of these regulations, as they will underpin your day-to-day actions regarding your own and others’ health and safety in the dental environment. The most important Act, which was a major advance in health and safety, is the Health and Safety at Work etc. Act 1974.

Health and Safety at Work etc. Act 1974

The Health and Safety at Work etc. Act 1974 applies to all workplace premises, including dental surgeries. It makes it clear that all employers are responsible not only for the health and safety of their staff but also of anyone who might be on their premises, such as patients or suppliers. All staff and visitors to a workplace should also act in a responsible manner and prevent any hazards occurring that may cause injury to themselves or others.

In addition to the Health and Safety at Work etc. Act 1974, the Dentists Act 1984 makes the employing dentist accountable for all faults or omissions made by their staff (including dental nurses).

Find Out More

If there are five or more employees in the workplace, the employer must have a written health and safety policy statement. Does your workplace require this? If it does, find out where it is located and who is responsible for it.

The employer’s responsibilities

Every employer should:

• Provide a health and safety policy
• Provide a safe working environment with no health risks
• Maintain the workplace (see Box 1.1.1), equipment and all work appliances in a safe condition
• Display the HSE’s health and safety law poster in a location where all staff can easily refer to it
• Ensure staff are aware of, and comply with, the provided health and safety policies and procedures
• Ensure staff are trained in the safe handling and storage of any hazardous substances and equipment
• Ensure risk assessments (see next section) are carried out and recorded
• Review health and safety performance at least annually and be aware of and investigate any failures or concerns.

BOX 1.1.1 Health and Safety Considerations in the Workplace

The workplace room temperature should reach at least 16 °C after one hour and all rooms should have thermometers to check this. Interestingly, there is no legislation covering temperatures that are high!

Enclosed workplaces such as a dental surgery should be ventilated with sufficient fresh or purified air to minimise exposure to dust, mercury, chemicals, nitrous oxide and disinfectant vapours. An open window will usually provide adequate ventilation, but mechanical ventilation or air-conditioning units could be considered. These should provide at least 5–8 litres per second of fresh (not recycled) air per occupant. The relative humidity should be between 40% and 70%.

All dental practices should have a first aid kit as well as the required emergency kit (see Chapter 2). All dental surgeries must also keep a stock of emergency drugs on the premises. Surgeries in which inhalational sedation is performed have further requirements to fulfil, to ensure nitrous oxide and any other gas levels are minimised.

Terms to Learn

Disinfection: a process by which the number of viable harmful micro-organisms is reduced in an area, e.g. a worktop in a dental practice. Disinfection does not get rid of certain micro-organisms, such as some viruses, or destroy certain forms of harmful micro-organisms, such as spores. Therefore it is only used for cleaning those areas of a dental clinic that only need to be acceptably safe. Disinfection can by carried out using special chemicals called disinfectants or by using heat.

Inhalational sedation: reducing or relieving anxiety using nitrous oxide and oxygen inhalation (in the dental workplace) (see Chapter 13).

Usually the employer will have liability insurance to cover any injury that occurs on the premises to either staff or visitors (e.g. patients and their accompanying people, contractors etc.).

Term to Learn

Liability insurance: a type of insurance that protects against claims of negligence or inappropriate action that were alleged to result in bodily injury (or property damage) to another person.

Employees’ Responsibilities

All employees, including dental nurses, have a duty to take reasonable care of their own health and safety. Therefore you are required to:

• Work to agreed procedures in accordance with the instruction and training given
• Report any suspected health problem related to your work
• Not enter certain designated areas unless you are authorised to do so
• Be trained in the use of the specified materials or equipment
• Not interfere with or misuse any equipment or item that is meant for the purpose of controlling or eliminating risk
• Report to your immediate supervisor or line manager, as a matter of urgency, any apparent faults in procedures or equipment.

Risk assessment

A risk assessment is simply a careful examination of what, in the workplace, could cause harm to people. Doing a risk assessment helps employers decide whether they have taken enough precautions, or should do more, to prevent harm from occurring to themselves, their staff or others.

A risk assessment should:

• Identify a hazard
• Consider whether anyone (e.g. especially certain staff handling specialised equipment, older people, pregnant women, children, etc.) may be harmed by that hazard
• Evaluate the existing precautions
• Take action to improve precautions and minimise the risk of the hazard occurring
• Record the findings
• Review regularly the arrangements – at least once a year.

Possible Risks in Dentistry: Some Examples

Handling dangerous substances:

• Certain dental materials used in the dental surgery and laboratory (e.g. acids) that could cause bodily harm if not used correctly
• Substances used for developing radiographs (X-ray films) (see p. 327).

Handling dangerous instruments (these may also be dangerous if hot):

• Extraction forceps and other surgical instruments
• Handpieces and dental burs
• Orthodontic pliers
• Sharps – instruments, scalpels, needles (see p. 14).

Handling dangerous machinery/equipment:

• Dental handpieces
• Electrosurgery equipment
• Heating equipment
• Laboratory equipment
• Lasers (see p. 16)
• Steam sterilisers (autoclaves).

Identify and Learn

Identify a pair of extraction forceps, a handpiece, a dental bur and a pair of orthodontic pliers in your workplace.

Terms to Learn

Sterilisation: a process by which an object is rendered free from all viable harmful micro-organisms, including viruses and bacterial spores. Therefore this method is used to decontaminate instruments that will be used inside a patient’s mouth.

Dental bur: a type of drill bit that is fitted into the dental handpiece and used for cutting or grinding the hard tooth material or bone. Also used in laboratory work.

Occupational hazards related to dentistry

Key Point

Dental nursing is one of the safest occupations.

Generally the risk of hazards occurring in the surgery are very low nowadays because of regulation and enforcement of good work practices by government authorities such as the HSE.

Most dental staff are in good general health. The more important concerns in the dental workplace are:

• Accidents
• Allergies
• Assaults
• Burns
• Chemicals
• Electrical
• Eye damage
• Fires and explosions
• Infections and inoculation injuries
• Lasers
• Noise
• Posture
• Pregnancy
• Pressure systems
• Radiation
• Stress.

Government regulations are in place concerning most of the above. The following sections explain how, as a dental nurse, you can reduce the risks by following the regulations.

Accidents

Legislation applying:

• Notification of Accidents and Dangerous Occurrences Regulations (1980)
• Reporting of Injuries, Diseases, and Dangerous Occurrences Regulations (RIDDOR) (1995)

Accidents occur in most workplaces, and dental premises are no exception. Accidents are more likely to happen when staff are not concentrating on their activities or are distracted. Obvious physical dangers to patients, staff and others include:

• Hitting the head or face on the dental light
• Trapping fingers or limbs when opening doors or moving the dental chair
• Being hit by a door opening without warning
• Damage from the dental handpiece or hot or sharp instruments
• Slipping or tripping over objects such as carpet edges and wires.

The hands and eyes are especially vulnerable when caustic fluids, needles, scalpels, wires or lasers, hot or rotating instruments are used. Risks related to the use of needles are explained in more detail in the section on ‘Infections and inoculation injuries’ (p. 14).

Identify and Learn

Identify a rotary instrument in your workplace.

Key Point

Staff and patients should always wear glasses or other eye protection during procedures involving the use of dental handpieces/burs, grinding or polishing, cutting wires, use of caustics or instrument cleansing.

The premises

Careful design and furnishing of clinical premises, especially flooring, and thoughtful behaviour, such as not running, can prevent many accidents (see Box 1.1.1 and ‘Accident notification’, p. 6).

• Floor coverings in clinics:

image be avoided
image Should be seam-free; where seams are present, they should be sealed
image The junctions between the floor and wall and the floor and cabinetry should be covered or sealed to prevent inaccessible areas where cleaning might be difficult.

• Work surfaces:

image Should be impervious and easy to clean and disinfect (e.g. Corian); check the manufacturer’s instructions for suitable products to clean.
image Joins should be sealed to prevent the accumulation of contaminated matter and aid cleaning.
image Junctions should be rounded or coved to aid cleaning.

Dental equipment

Much of the equipment used in dentistry constitutes some hazard to staff and sometimes to the patient or others. All equipment must therefore be carefully and regularly maintained by an appropriately trained person. This is covered in more detail below.

Recording and notifying accidents

All accidents and injuries to staff or patients or visitors while on the premises, however apparently trivial, should be recorded in an accident book. Her Majesty’s Stationery Office (HMSO) publishes an ‘Accident Book’, which is suitable for use in the dental environment.

Find Out More

Where is the accident book kept in your workplace? Who supplies it?

Employers must notify the HSE of accidents causing death or ‘major injury’ to any person or ‘dangerous occurrences’, even if there has been no death or injury. They also have to keep records of the event.

Under the regulation called RIDDOR, any injury occurring in a workplace should be reported if the person:

• Requires 24-hour hospitalisation for treatment

or

• Requires sick leave for three or more days

or if the injury involves any of the following:

• Fracture of skull, spine, pelvis or limbs
• Loss of sight
• Unconsciousness from hypoxia or chemical exposure
• Explosions or fires
• Major mercury spillage
• Acute ill health from exposure to a pathogen.

Terms to Learn

Hypoxia: the condition in which the cells in the body (especially the brain) receive an inadequate amount of oxygen to carry out their tasks.

Pathogen: an agent that can cause disease, e.g. bacteria.

Thus, for example, in the dental practice, a compressor or steam steriliser (autoclave) explosion could be notifiable, as could a mercury spillage. In case of doubt of whether an injury should be reported, the advice of the local HSE office should be sought.

Term to Learn

Steam steriliser (autoclave): a pressure vessel in which steam at high pressure is produced. When instruments are placed in the steam steriliser for a certain amount of time, the high temperatures in the steam help to kill the harmful micro-organisms or their spores that may be attached to the instruments.

Reports related to RIDDOR should be immediately given by telephone to HSE, and a completed accident report form (2508) sent to the HSE within 10 days. Incident reporting forms can be downloaded from the HSE website (https://www.hse.gov.uk/forms/incident/f2508.pdf) or obtained from The Stationery Office Bookshop (www.tso.co.uk/contact). A copy of the completed 2508 form should also be kept by the employer.

If the incident does not result in a reportable injury but clearly could have done so, it is classed as a dangerous occurrence and must also be reported immediately by completing form 2508. A full list of what are ‘dangerous occurrences’ and the employer’s responsibilities are given in the RIDDOR 97 leaflet. (A needlestick injury (p. 14), involving an infected patient may also fall in this category.)

Find Out More

Visit the HSE website (www.hse.gov.uk/riddor) for more information about RIDDOR.

Key Point

Although RIDDOR applies to all places of work including dental premises it excludes accidents to ‘patients when undergoing treatment in a hospital or surgery of a doctor or dentist’. That exclusion only applies to patients when undergoing treatment – the RIDDOR rules do still have to be followed if, for example, a patient breaks a leg on the surgery doorstep.

Reporting diseases under riddor

If the employer is notified by a doctor that an employee has a reportable work-related disease or infection (e.g. occupational dermatitis, occupational asthma, tuberculosis, hepatitis B, legionnaires’ disease), the HSE must be sent a completed disease report form (2508A; available at: https://www.hse.gov.uk/forms/incident/f2508a.pdf).

Find Out More

Of the responsibilities listed in Box 1.1.2 which would be the dental nurse’s responsibilities? Make a list and get your supervisor to comment on it.

BOX 1.1.2 Minimising Accidents in the Dental Surgery and Laboratory

• Avoid unnecessary rushing about and horseplay.
• Paths and doors should not be obstructed by trailing wires or any other hazards.
• Passageways and staircases should be well lit, secure and not obstructed, and cleaned daily.
• Floor surfaces should be clean, non-slip, and have a minimum of joints.
• Furniture should be strong, safe and secured where necessary.
• Staff should use appropriate steps or stepladders when reaching for objects in high places.
• Fires, heaters, Bunsen burners, etc. should be guarded.
• Flammables, explosives and toxic materials including domestic bleach should be safely stored and labelled correctly.
• There should be procedures for regular maintenance of all equipment, especially steam sterilisers and compressors because of the risk of explosion.
• Heat treatment and casting equipment should be housed adequately, and tongs used for handling heated casting rings.
• Acid baths should be properly housed and protected.
• All electrical equipment should be installed, earthed, fused and connected, and maintained properly.
• Cables and tubing from electrical and other equipment should not trail on the floor.
• All gas appliances should be installed, connected and maintained properly.
• Electrical, radiography, pressure and gas appliances should be turned off outside working hours.
• Staff and others should avoid injuries from sharps by using appropriate waste disposal.
• Staff should wear protective attire as appropriate.
• Staff should adhere to the practice safety policy.
• Staff should not smoke, eat or drink on the premises except in designated areas.
• Staff should know the hazards of, and preferably stop, smoking.
• Safety training and refresher courses should be taken by all appropriate staff.
• Staff should not use radio headsets and iPods and listen to overloud music, all of which isolate the wearer from the surrounding environment, and have resulted in many accidents.

Terms to Learn

Casting equipment: the equipment used in a dental laboratory to make fixed restorations such as crowns (see Chapter 9).

Acid bath: a solution containing acid that is used to stop the developing process for X-rays.

Allergies

Allergic reactions are common and usually minor but some are potentially lethal. People with asthma, eczema and some other conditions often have underlying allergies. Sometimes allergic reactions can be very severe (called anaphylaxis; see Chapter 2).

Many allergies have a hereditary component but the prevalence of allergies appears to be increasing. Table 1.1.1 lists some common allergens.

TABLE 1.1.1 Common Allergens

Source of Allergen Examples
Food products Milk, nuts, egg, shellfish
Drugs Aspirin, penicillins,
Environmental Animal hair, dust mite, pollen
Latex Condoms, elastic bands, gloves
Dental materials Amalgam alloy, gold, mercury, resin-based materials

Key Point

Some dental materials may produce allergic reactions.

Latex allergy

Latex allergy has become a significant clinical problem, along with allergies to iodine, plasters (e.g. Elastoplast and Band-aid) and drugs (remember this with the acronym LIED – Latex Iodine Elastoplast Drugs). Latex products are common in the home and workplace including clinics, wards and operating theatres. Therefore allergy is an important occupational problem, especially with handwashing using abrasive materials, which increases the risk of sensitisation. Allergic reactions to latex have become increasingly common since the use of protective medical/dental gloves became mandatory following the advent of HIV/AIDS. Latex exposure may occur via the skin, mucous membranes, or respiratory tract (see Subchapter 4.1) with inhalation of latex glove powder (natural rubber latex (NRL) allergens may attach to lubricating powder, and become aerosolised, causing sensitisation; or, in those who are allergic, they can cause respiratory, ocular or nasal symptoms).

‘Low-allergen’ latex gloves are available but there is little certainty that these offer any real benefit. People who have allergies to one type of substance are more likely to have allergies to others; patients with latex allergy, for example, may react to foods with allergen cross-reactivity such as avocado, banana, chestnut and kiwi.

Term to Learn

Sensitisation: a change in response by the body to a foreign substance, usually an allergen, so that on subsequent exposures to that substance the body shows a heightened immune response (see Subchapter 4.1).

HIV: human immunodeficiency virus, the virus that causes AIDS.

AIDS: acquired immune deficiency syndrome, a fatal disease. People with AIDS have problems with their immune system and so catch infections more easily.

Many items used in dental practice can sometimes contain latex (Box 1.1.3) and even equipment and laboratory work previously handled with latex gloves may elicit an allergic response.

BOX 1.1.3 Latex in Dental Items*

• Equipment and laboratory work previously handled with latex gloves
• Adhesive dressings and their packaging
• Amalgam carrier tips**
• Bandages and tapes
• Chip syringes**
• Dappen pots**
• Endodontic stops**
• Gloves
• Gutta-percha and gutta-balata**
• Headgear and head positioners**
• Induction masks**
• Latex ties on face masks
• Local anaesthetic cartridges**
• Mixing bowls**
• Needle guards
• Orthodontic elastics**
• Prophylaxis cups and polishing wheels and points**
• Protective eyewear
• Rubber dam**
• Rubber gloves
• Rubber sleeves on props, and bite blocks**
• Spatulas**
• Suction tips**
• Surgical face masks and other protective items of clothing e.g. gowns, overshoes
• Tourniquets and blood pressure cuffs
• Wedges

* Latex is present in some rubber dental local anaesthetic cartridges, stoppers or plungers, where either the harpoon penetrates or where the flat piston end of a self-aspirating syringe rests. At the other end of the cartridge is the diaphragm, which the needle penetrates. Any of these components may contain latex. Although there are no documented reports of allergy due to the latex component of cartridges of dental LA, the UK preparation of prilocaine (Citanest) contains no latex.

** See ‘Identify and Learn’ above.

Identify and Learn

Identify all the dental materials and instruments marked with ** in Box 1.1.3 in your workplace.

Diagnosis of an allergy is based on:

• Clinical history and presentation
• Family history of allergy
• Skin-prick or patch testing
• Elimination diet to identify food allergens.

To avoid future allergic reactions, known allergens should be avoided, which is easier said than done. This is because sensitive individuals may react to minute traces of an allergen, and because allergens can be present in the most unexpected places.

Key Point

For latex allergy, anything containing, or contaminated by, latex should be avoided: a latex-free clinic is ideal.

Patients who have had serious allergic reactions such as anaphylaxis (see Chapter 2) are also usually advised to always carry with them adrenaline for subcutaneous self-injection in the event of a reaction (e.g. Epipen). Affected individuals are usually advised to wear a warning emblem such as Medic-Alert.

Treatments for allergies include use of various drugs such as antihistamines.

Term to Learn

Subcutaneous: the tissues of the body just under the skin.

Assaults

Occasionally dental staff are victims of assault by patients who may be drunk, stressed, have mental problems or may be drug abusers. Potentially dangerous incidents should be defused where possible. If you are assaulted, the most effective response will be to:

• Stay calm
• Avoid confrontation – verbally, by body language or physically
• Listen to the person
• Empathise with the person
• Seek help if the situation does not resolve.

Guidelines governing the prosecution of violent offenders who target NHS staff have been issued by the Crown Prosecution Service (CPS) and the NHS Security Management Service (NHS SMS).

Find Out More

To read more about security in the workplace, see the NHS website: www.nhsbsa.nhs.uk/413.aspx.

Burns

Burns can result from chemical (acids) or physical agents (heat, cold, radiation such as X-rays or lasers).

Chemical burns

Several acids (e.g. phosphoric acid, chromic acid and trichloroacetic acid) and corrosive agents (e.g. sodium hypochlorite) are used in the dental surgery and can cause burns if they are not used carefully. Many other stronger acids and corrosives are used in the dental laboratory (e.g. hydrofluoric, sulphuric and nitric acids, and caustic soda or sodium bicarbonate). All acids and caustic solutions should be stored safely in appropriate and clearly labelled containers, and proper safety precautions should be taken when handling these materials.

Thermal burns

Thermal burns can happen when taking out hot instruments or materials from steam sterilisers or microwaves. Several dental instruments, such as extraction forceps, elevators and metal mouth gags, in particular, retain heat for several minutes after being sterilised and so can cause burns to staff and to patients if used immediately after sterilisation. Handling dental handpieces that have overheated during use can also cause heat burns. This often happens because of the difficulty in gauging their temperature through the gloves that all staff are required to wear in the clinic.

Hot wax knives and Bunsen burners are also common causes of burns; long hair and gloves or clothing can catch light in a Bunsen flame. Hot air blowers can reduce this danger, although they take somewhat longer to heat objects.

Other possible causes of thermal burns in the dental environment include handling hot gutta-percha, dental composition, wax and boiling water, lasers, diathermy and even heated operating lights. Diathermy accidents have resulted from metallic parts of the dental chair becoming part of the path of the current – the localised increase in current density can then cause superficial burns of the skin.

Identify and Learn

Identify gutta-percha, dental composition, a wax knife, diathermy unit and an elevator in your workplace and find out what they are used for.

Cold burns

Cold burns may occur from spillage of liquid nitrogen, which is used, for example, for cryotherapy or to freeze some biopsy specimens.

Term to Learn

Cryotherapy: a method of destroying abnormal cells in the skin or mucosa usually by freezing them with an extremely cold liquid or instrument.

Chemicals (Hazardous Substances)

Legislation applying:

• Control of Substances Hazardous to Health Regulations (COSHH) 2002

All dental surgeries and laboratories must undertake risk assessments of all chemical and potentially hazardous substances used in the premises. The results of the assessments must be recorded in a COSHH report. The report must include:

• The hazards a material poses
• How the hazards can be avoided
• How to deal with a hazard should it occur.

Hazardous materials in general include:

• Substances used directly in work activities (e.g. adhesives, cleaning agents)
• Substances generated during work activities (e.g. fumes from soldering)
• Naturally occurring substances (e.g. dust)
• Biological agents, such as bacteria and other micro-organisms.

Hazardous materials in dentistry include:

• Sodium hypochlorite
• Acid etchants
• Mercury
• X-ray fixers
• Flammable materials.

Find Out More

Read the COSSH reports of five hazardous materials that are used in your dental practice. See also the COSSH publication ‘Working with substances hazardous to health’ (www.hse.gov.uk/pubns/indg136.pdf).

Identify and Learn

Identify an acid etchant and the X-ray fixer used in your workplace.

Employers are required to:

• Assess the risks to health from chemicals and decide what controls are needed
• Use those controls and make sure staff use them
• Make sure the controls are working properly
• Inform staff about the risks to their health
• Train staff.

Gases and volatile liquids

A dental nurse may be exposed to anaesthetic gases (nitrous oxide) and vapours for a significant part of their career if the equipment used to administer the gases is faulty, poorly maintained or used without an effective scavenging system, or if the agents are misused. These gases, which are also called inhalational agents, are used in conscious sedation (nitrous oxide) and general anaesthesia (nitrous oxide, isoflurane, enflurane, sevoflurane and desflurane; halothane is no longer commonly used – see below). Anaesthesia is covered in detail in Chapter 13.

Under normal working conditions, our mental and nervous responses, that is, how alert we are and how quickly and appropriately we react to situations, are not much impaired by exposure to inhalational agents. However, if a clinician is exposed to excessive amounts of these gases or over a long period of time, not surprisingly, their responses can be impaired. They may also develop numbness, difficulty in concentrating, paraesthesias (‘pins and needles’) and dizziness. Nitrous oxide exposure for prolonged periods can also have adverse effects on other organs of the body, for example the heart, liver and bone marrow, and the reproductive organs.

Halothane and some other halogenated inhalational agents (sevoflurane and desflurane) can cause severe liver dysfunction (called hepatotoxicity) and problems with the beating of the heart (called arrhythmias). Therefore halothane is no longer recommended for use in adults. Only occasional hepatotoxicity has been reported with enflurane and isoflurane.

Term to Learn

Arrhythmia: when the heart beats too slowly or too rapidly or irregularly or too early.

Clearly, all dental practices should take steps to control and minimise the exposure to inhalational agents (see Box 1.1.4).

BOX 1.1.4 Precautions to Take while Using Nitrous Oxide

• Careful use of well-maintained equipment
• Adequate room ventilation
• High-volume vacuum ejectors
• Effective scavenging systems.

A Note about Ventilation

• A dental surgery should be adequately ventilated; often an open window will suffice but, in some cases, especially where gases are used, it might be appropriate to install an extractor fan, or a scavenger system. Recycling air conditioning systems are not recommended.
• Systems should exhaust to the outside of the building without risk to the public or recirculation into any public building.
• Fresh air supply rate should not fall below 5–8 litres per second per occupant and should not create uncomfortable draughts.
• Mechanical systems must be regularly cleaned, tested and maintained according to the manufacturer’s recommendations to ensure they are free from anything that may contaminate the air.

Identify and Learn

Identify a vacuum ejector in your workplace.

Electrical Hazards

Regulations applying:

• Electricity at Work Regulations 1989
• Electrical Equipment (Safety) Regulations 1994

Quality control

The Electrical Equipment (Safety) Regulations 1994 state that all electrical equipment should be constructed and designed for safe use when connected. This should be achieved by providing protection against electric shock through a combination of insulation and a protective earthing conductor. The main hazards from electrical equipment are:

• Contact with live parts causing shock and burns (normal mains voltage, 230 volts AC, can kill).
• Faults which could cause fires – where electricity could be the source of ignition in a potentially flammable or explosive atmosphere.
• The risk of injury from electricity is strongly linked to where and how it is used, being greatest:

image In wet surroundings
image In cramped spaces.

Inspection routines

Electricity plugs, cables, etc. should be inspected every six months. All electrical equipment should be regularly tested by an appropriately qualified person at least every two to three years, with records kept of the test results.

Measures to Reduce Electrical Accidents

• Instruction of personnel in the correct use of equipment.
• Frequent periodic maintenance of apparatus and wiring.
• Earthing of all apparatus.
• Separation of mains circuits.
• Use of earth leakage circuit breakers.

Eye Hazards

Eyes need protection from foreign bodies, infected material, chemicals and the various forms of radiation used in dentistry – lasers, light sources for curing (ultra-violet/visible blue or white halogen light) and X-rays. These are covered in more detail on page 16.

Term to Learn

Curing: the process of hardening of tooth-coloured materials that are used mainly to fill teeth with cavities. The materials come in paste form and harden either by a chemical reaction or on application of a special light (see Chapter 9).

Patients

Patients must always be provided with adequate eye protection – particularly if they are being treated in the supine position (lying on the back) and for procedures being carried out under conscious sedation or general anaesthesia.

Staff

All clinical staff should always wear protective eyewear at work. Objects such as bits of fillings can behave like projectiles and fly out of the mouth at speeds of over 10 m/s when using drills at 250 000 revolutions per minute (rpm). The ends of orthodontic and other wires should be held in mosquito forceps, and when cutting, the wire should always be held between two forceps so that the cut end does not fly off and cause eye damage.

Special eyewear is needed for work with lasers and with curing lights. Remember that ordinary dark glasses do not filter the hazardous wavelengths of lasers and curing lights. Rather, because they absorb visible light, they can dilate the pupils (open them wider) and therefore worsen the problem because more of the hazardous light rays can now enter the eyes. Contact lens wearers should be careful not to get powders or other materials behind their lenses.

Identify and Learn

Identify a pair of mosquito artery forceps in your workplace.

Fires and Explosions

Legislation applying:

• Fire Precaution (Workplace) Regulations
• Regulatory Reform Fire Safety Order 2006

Human error is responsible for most fires and explosions. The main causes of fire in a dental practice or similar place usually are: electrical faults (see p. 12); careless use of matches; incorrect use of flammable gases (e.g. oxygen) and fluids; and non-electrical heating.

A commonsense approach, particularly avoiding the use of naked flames and taking care in the use and storage of flammable materials, will prevent many problems. For example:

• Gas cylinders should be securely stored so that they cannot fall, in a room separate from flammable materials.
• Steam sterilisers (autoclaves) and surgery air compressors should be used and maintained properly. All pressure vessels must be regularly maintained.

Employer and employee responsibilities

Employers must comply with fire safety regulations. This means carrying out a fire risk assessment to determine what precautions are needed and putting in place fire precaution measures. If there are five or more employees, the fire risk assessment must be written down.

• Fire precaution measures could include fire alarm systems and extinguishers as well as clearly signed escape routes (see also Box 1.1.5).
• All flammable materials (e.g. oxygen, gas cylinders, alcohol, monomer, methylated spirits) must be stored in a metal cabinet and never used near flames, or a fire or explosion could result.
• Fire-fighting equipment such as extinguishers and blankets must be kept on the premises, regularly inspected and serviced by an authorised body. Staff should be aware of the location of fire-fighting equipment, as well as the colour coding for use on different types of fire.
• Fire exits must be marked with the appropriate green signs, kept free of any obstruction, and kept unlocked/unbolted during normal working hours, for emergency exit and for access if required by a fire and rescue service (fire brigade).
• The fire regulations should be clearly displayed in the reception area – they must be clearly seen by all staff, patients and visitors. They should also appear in the practice manual and patient leaflets.
• Emergency lighting may be necessary.
• An assembly point must be noted outside the premises.
• The fire drill should be practised regularly.

BOX 1.1.5 Steps to Take in the Event of a Fire

1. Activate the fire alarm or call out ‘fire’.
2. Call the Fire and Rescue Service.
3. Locate the fire source and extinguish if safe to do so.
4. Evacuate all patients and staff from danger.
5. Close the doors and windows.
6. Assemble all people at the designated assembly point.

Key Point

The safety of employees and visitors in the event of a fire rests with the responsible person of the organisation. If an employer is negligent, they could be prosecuted.

Infections and Inoculation Injuries

Dental staff are commonly exposed to respiratory infections, mainly ‘colds’, and other viral throat and chest (respiratory) infections. Other more serious respiratory hazards are ‘flu’ (influenza), tuberculosis (TB) and, to a much lesser extent, Legionella infection (also called legionnaires’ disease). All these infections could also be transmitted to patients or others (see Subchapter 1.2).

The main infectious hazard in the dental practice is contact with infected body fluids (blood, saliva, etc.). Infections can be transmitted via sharps injuries (needlestick injury; inoculation, particularly those caused by viruses such as hepatitis B, hepatitis C and human immunodeficiency virus (HIV). Prions, which cause Creutzfeldt–Jakob disease (CJD), are virtually impossible to destroy. MRSA (meticillin-resistant Staphylococcus aureus) infection is mainly a healthcare-associated infection (HCAI).

Terms to Learn

Prion: a microscopic protein particle that can cause disease.

HCAI: infection that is caught by a patient from another patient, staff or visitor during stay in a hospital or visit to another healthcare facility.

Inoculation (sharps or needlestick) injuries

Inoculation injuries include all incidents where a contaminated object or substance enters the body through a breach in the skin or a mucous membrane (see Subchapter 4.1) or comes into contact with the eyes. Typical examples of inoculation injuries are:

• Sticking or stabbing with a used needle or other instrument – particularly when re-sheathing a needle
• Splashes with a contaminated substance to the eye or other open lesion
• Cuts with contaminated equipment
• Bites or scratches inflicted by patients.

Key Point

Sharps injuries are one of the main hazards for dental nurses. The clinician or you must dispose of needles into a special sharps container (see p. 40) to avoid the risk of injury.

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Related posts:

  1. 16: Dental Emergencies
  2. 12: Dental Drugs, Materials, Instruments and Equipment
  3. 4: Anatomy and Physiology
  4. 2: Medical Emergencies and First Aid in the Dental Surgery
  5. 10: Surgical Procedures
  6. 17: Human Diseases and Health Promotion

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Jan 8, 2015 | Posted by in Dental Nursing and Assisting | Comments Off on 1: Health and Safety, Occupational Hazards and Infection Control in the Dental Workplace

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