Large quantities of clinical waste are produced every day from a wide range of sources. Clinical waste can be classified according to a number of categories, depending on its source. Clinical waste is defined by the Controlled Waste Regulations (1992) as any waste that consists wholly or partly of:

• blood or other bodily fluids
• drugs or other pharmaceutical products
• excretions
• human or animal tissue
• swabs or dressings
• syringes, needles or other sharp instruments which, unless made safe, may be hazardous to anybody who comes in contact with it.

Examples of clinical waste include:

• any item which is or may be soiled by blood or body fluids
• colostomy and urine bags
• empty IV bags and administration sets
• human tissue
• incontinence bags
• pharmaceutical waste
• vomit bowls and sputum pots
• waste arising from treatments using cytotoxic drugs (HSAC 1999).

The principal sources of clinical waste are:

• blood transfusion centres
• dental surgeries
• GPs' surgeries
• health centres
• hospitals
• research establishments
• public health laboratories
• veterinary surgeries (DETR 1999).

Unless clinical waste is properly segregated, handled, transported and disposed of it can present risks to the health and safety of people at work, members of the public, and the environment.

Clinical waste demands far more stringent management than general waste, this is reflected in higher disposal costs. Recent studies suggest that as much as 50% of waste sent for incineration as clinical waste is in fact general waste, leading to unnecessarily high disposal costs (Mercier and Ellam 1996). Improved segregation can generate substantial savings. In an ideal world, segregation of waste should take place at the point of production, for example on the wards or in operating theatres. For this to happen staff must understand the reasons for segregation and be aware of what happens to the waste they generate. According to the BMA, waste management is rarely practiced. Waste is treated merely as material to be disposed of (BMA 1994). Hospitals once benefited from Crown Immunity allowing them to incinerate waste on site. This discouraged inv.htmlent in waste management. Removal of immunity in 1991 has meant that the NHS is now subject to the full force of legislation (Mercier and Ellam 1996).

It has in been estimated that the NHS Trusts generate 193,000 tonnes of clinical waste every year (Audit Commission 1997a). It is likely that other sources produce a similar quantity. At that time acute wards produced an average of 0.2 tonnes of waste per bed per week. The same study concluded that Trusts should focus their attention on waste management.

In recent years, there has been an increase in the amount of clinical waste coming from households. This is due in part to changes in health care polices, including early post-operative discharges and home care of the elderly (NHHWF 1998). Self-injecting diabetics and people changing colostomy bags at home can also generate significant quantities of clinical waste. Clinical waste also arises in public places. A 1995 survey estimated that every county and metropolitan council collected an average of 500 tonnes of clinical waste, or approximately 0.15% of total municipal solid waste (NAWDO 1995).

Most households do not produce clinical waste. Sanitary wastes (otherwise known as human hygiene wastes) from households (e.g. sanitary towels, tampons and nappies) are not considered to be infectious or clinical waste. The assumption being that the source population is generally healthy (HSAC 1999). Human hygiene wastes generated in other public places, such as shopping centres, schools and nurseries, offices and factories are considered in the same way. This waste is, however, generally unpleasant and offensive and it is appropriate to package it separately to other waste streams (HSAC 1999). The national Bag it and Bin It campaign is aimed at improving the management of human hygiene wastes from householders (see Types of Waste A-Z Listing: Paper and Board).

When dealt with incorrectly, clinical waste represents a risk both to people and to the environment. The regulations concerning the management of this waste stream reflect these risks. Clinical waste presents two primary risks - infection and toxicity. They can affect humans in three principal ways:

• biologically (exposure to pathogenic micro-organisms)
• physically (contaminated sharps penetrating the skin)
• chemically (exposure to liquids, gases, etc) (NHHWF 1998).

Table 1 shows the five categories of clinical waste and their associated hazards.

Table 1 Categorisation of clinical waste

GROUP	DESCRIPTION
A	Includes the following items: identifiable human tissue, blood, animal carcasses and the tissue from veterinary centres, hospitals or laboratories. Soiled surgical dressings, swabs and all other similar soiled waste. Any infectious waste material excluded from Groups B-E.
B	Discarded syringes, needles, cartridges, broken glass and other contaminated disposable sharp instruments or items.
C	Microbiological cultures and potentially infected waste from pathology departments and other clinical or research laboratories.
D	Drugs or other pharmaceutical products.
E	Items used to dispose of urine, faeces and other bodily secretions and excretions that do not fall within group A. This includes used disposable bedpans or bedpan liners, incontinence pads, stoma bags, catheter bags and tubes and urine containers.

Note

1 All identifiable human tissue, whether infected or not , may only be disposed of by incineration.

2 Where the risk assessment shows there is no infection risk, Group E wastes are not defined as clinical waste.

SOURCE: HSAC 1999

Regulation of clinical waste management comes under health and safety legislation and waste management legislation. In recognition of this, the Health Services Advisory Committee (HSAC) of the Health and Safety Commission, and the Environment Agency has jointly prepared guidance. It provides advice on managing clinical waste through safe segregation, handling, transport and disposal (HSAC 1999). It is a vital document for all managers of clinical waste.

The management of clinical waste in the 1990s saw a number of changes as a result of tighter environmental legislation. Understandably, as the major producer of clinical waste, the National Health Service (NHS) has been especially affected. Before 1989, the majority of hospitals had their own incinerators and clinical waste was incinerated on site. The NHS had Crown Immunity from environmental legislation such as the Clean Air Acts of 1956 and 1968. In the 1990s the majority of hospital incinerators closed as a result of:

• the NHS and Community Care Act 1990, which abolished Crown Immunity to environmental legislation; interim emission standards were set to be met by 1993
• the Environmental Protection Act 1990, which introduced tighter emission standards for incinerators and in effect made small-scale incinerators unsuitable for the disposal of clinical waste.

In Scotland there are now only seven treatment plants processing NHS clinical waste compared to 200 in 1990.

It is vital that effective health, safety and environmental systems are in place to minimise the risk from clinical waste to human health and the environment. The two key areas of legislation regulating the management of clinical waste are outlined below.

Employers generating clinical waste must ensure that the risks are properly controlled through:

• risk assessment
• developing policies and procedures for managing the risk
• monitoring the procedures to ensure that they are effective (HSAC 1999).

The main legislation is:

• Control of Substances Hazardous to Health Regulations 1999 (SI 1999/437)
• Transport of Dangerous Goods (Safety Advisors) Regulations 1999 (SI 1999/257)
• Management of Health and Safety at Work Regulations 1992 (SI 1992/2051).

Clinical waste is controlled waste as defined by the Controlled Waste Regulations 1992 (SI 1992/588). It is covered by the following main pieces of legislation:

• Environmental Protection Act 1990 (EPA 1990)
• Special Waste Regulations 1996 (SI 1996/942) (some clinical waste is also classified as special waste and the Environment Agency have issued technical guidance on the definition)
• Waste Management Licensing Regulations 1994 (SI 1994/1056)
• Environmental Protection (Duty of Care) Regulations 1991 (SI 1991/2839) (HSAC 1999).

It is of particular concern to generators of clinical waste that they comply with the Duty of Care requirements of the EPA 1990. The types of precautions that must be taken are dependent upon the relevant legal requirements as well as the results of a risk assessment. The precautions relate to:

• accidents, incidents and spillages
• handling
• immunisation
• labelling
• packaging
• personal hygiene
• personal protective equipment
• segregation
• storage
• training and information
• transport on and off site
• treatment and disposal (HSAC 1999).

• household hospital waste
• clinical waste.

Household hospital waste is similar in constitution to normal household waste. It is typically bulkier and heavier than clinical waste and, although it does not represent a risk to human health or the environment, efforts should be made to reduce its production at source.

Different categories of clinical waste can be dealt with in different ways. The most common method of segregating waste is by using colour-coded bags, as shown in Table 2.

Table 2 Colour coding of clinical waste

COLOUR	TYPE OF WASTE
Yellow	Group A clinical waste which will be incinerated in a clinical incinerator or otherwise disposed of.
Yellow with black stripes	Non-infectious waste, e.g. Group E and sanitary products, which is suitable for landfill or other means of disposal.
Light blue or transparent with blue lettering	Waste for autoclaving or equivalent treatment before disposal.
Black	Treated clinical waste, non-clinical waste and household waste.

SOURCE: HSAC 1999

An Audit Commission report, produced in 1997, confirmed that the lack of waste segregation is a problem in the health service. General waste is frequently disposed of in clinical waste receptacles (e.g. yellow bags). Supportive research found that an average of 65% of the material in the clinical waste collection was non-clinical (Ison 1998). In 1997 the cost of clinical waste disposal ranged between £180-£320 per tonne. This is more than double the figure for household waste, which ranges between £20-£70 per tonne (Audit Commission 1997a).

Implementing stricter segregation could substantially reduce waste costs. Some hospitals are better at this than others. The amount of waste disposed of as 'clinical waste' can range from over a tonne to less than quarter of a tonne per bed per month (Audit Commission 1997a). Savings can be dramatic; for example, a large teaching hospital identified savings of £250,000 per year from careful segregation of its waste (Audit Commission 1999).

The following measures can help to improve segregation:

• the training of relevant staff. Doctors and cleaners were found to be poorly trained in clinical waste management
• clear sign posting and ongoing communication to staff
• an ample supply of coded waste sacks
• a system of communication with staff over the need and implications of a good waste segregation policy (Ison 1998).

The feasibility of purchasing reusable equipment needs further investigation. There is a cost attached to reusable equipment, in terms of staff time and the necessary re-sterilisation equipment. However, there is still scope to introduce reusable equipment in some areas (e.g. reusable kidney dishes) (Audit Commission 1997a). This will reduce the amount of clinical waste arising, as disposable products are classified as clinical waste.

The most common form of disposal for clinical waste is incineration. Since 1990 the EPA requires that only certain types of clinical waste such as body parts and chemicals are incinerated (Audit Commission 1999). Alternatives include maceration, heat or chemical treatment. Some NHS Trusts are exploring new cost-effective alternative solutions (Audit Commission 1997a).

Most NHS Trusts have opted to contract out the collection of clinical waste to waste management companies in an effort to minimise risk (Audit Commission 1997a). Smaller generators of clinical waste are being encouraged to seek suitable waste contractors.

The project was based at operating theatres in two hospitals in the Thames region: the John Radcliffe Hospital Trust in Oxford, and the Horton General Hospital Trust in Banbury.

The overall aim of the study was to identify opportunities for best practice in resource use and waste management for health care delivery. The main measure used was the amount and nature (solid, liquid and gaseous) of the total wastes generated using suction receptacles in operating theatres.

The hospitals were selected as the John Radcliffe currently uses a disposable system in theatres, whilst the Horton General employs a durable system. The study compared the costs of the two systems.

The major findings of the study were:

• That disposable systems had a significantly higher negative impact upon the environment than durable ones. The impacts include energy consumption, resource depletion and contributions to environmental problems such as global warming, acidification and toxicity to humans.
• Disposable systems cost significantly more than durable systems in terms of both purchasing and disposal costs. Disposal costs are unlikely to fall in the future.
• The use of durable products highlighted opportunities for cost and energy savings as well as reduced environmental impacts through the use of efficient washing and drying facilities. One hospital managed almost to halve the comparable costs incurred at another hospital by using much shorter operating cycles.
• One measurement suggested that contrary to the perception of some managers, the disposal system might in fact pose increased risks. It showed that 70% of used receptacles were not fully sealed for disposal, posing an increased potential risk to unqualified staff and the general public. This highlights the need to carry out further work to quantify and evaluate the risk potential of both systems in more detail.

SOURCE: ISON 1998; HOLDING ET AL 1999

In 1996, the Pembrokeshire NHS Trust implemented a system to reduce the amounts of clinical waste it produced.

The system operated as follows:

• the numbers of black and yellow bags used were monitored
• targets were set to reduce the proportion of yellow clinical waste bags to black household waste bags
• cardboard was dealt with separately from the rest of the waste stream
• each ward was visited to check that the correct options were provided wherever possible.
• information on the differing costs of clinical and household waste disposal was posted above disposal points in an effort to raise awareness of the purpose of the exercise
• continual monitoring was implemented with wards revisited at regular intervals to check compliance with the new arrangements. Statistics were kept to evaluate the effects of the policy
• the system allowed infringements to be reported to the senior managers.

Statistics from this system showed that total waste production remained the same. Despite this, significantly more waste was placed in the black bags and less in the yellow bags over a six month period. Monitoring has shown a sustained change.

The project benefited from the support of the Chief Executive and the full involvement of the Control-of-infection Nurse, who intensified and extended her courses for staff involved in handling waste.

SOURCE: AUDIT COMMISSION 1997B

The management of clinical waste is likely to undergo a change in the near future as tighter regulations are implemented. Clinical waste which is classified as special waste will be subject to the requirements of the EU Landfill Directive 99/31 (see European Legislation Affecting Waste Management). Pre-treatment will be required for all such clinical wastes, prior to landfilling at a licensed site. Hospital, and other, clinical waste which is infectious will be banned from landfill, as will waste drugs which should either be treated to destroy component chemicals or incinerated.

The high costs of dealing with clinical waste are likely to increase further as a result of the Landfill Directives requirements and landfill tax increases. These are added incentives for hospitals to minimise the amount of waste they produce, and to implement waste management systems.

Businesses that transport large quantities of clinical waste by road or rail may have to appoint a Dangerous Goods Safety Adviser under the Transport of Dangerous Goods (Safety Advisers) Regulations 1999 (SI 1999/257).

The proposed Directive on Hazardous Municipal Waste may or may not go ahead. Should it be implemented, it would mean that consumers would have to be informed of the need for the separate collection of certain domestic sources of clinical waste. These would include syringes, needles and medicines.