Low Dead-Space Syringes

As professionals working in the drug and alcohol field, reducing harm for people who access these services is at the core of the work we do.

Although all injecting equipment should be for single use only, it is believed that not enough injecting equipment is distributed, and hepatitis C re-infection rates alongside data collected by UKHSA demonstrate that the sharing and re-use of equipment is still taking place.

With the knowledge that sharing is still taking place, how do we help to reduce the risk?

One way to reduce the risk is low dead-space syringe and needle provision.

What is low dead-space in a syringe?

The ‘dead space’ is the void space in the syringe that contains blood after it has been used.

Low dead space injecting equipment has less space between the tip of the needle and the plunger after injecting. Blood and drug(s) remain in this space, so if syringes and needles are shared the risk of spreading blood borne viruses such as HIV and Hepatitis C may be lower when there’s less space for blood to be left in the equipment.

Previous research has found that low dead-space syringes could reduce the chance of spreading infections, such as HIV and Hepatitis C, if they are re-used or shared because there is less blood and therefore less virus.

Some needles and syringes have a greater dead-space than others.

Below are some examples of syringe and needle combinations available on the market.

The first image is a conventional syringe and needle combination with full dead-space between needle and plunger, this is classed as a high dead-space needle and syringe combination.

The second image is an example of a syringe with a modified plunger to reduce the dead-space between plunger and needle, this is classed as a reduced dead-space needle and syringe combination. It has about half the dead-space of a high dead space syringe.

The third image is a needle that has a modified hub to reduce the dead space between the plunger and needle, this is classed as a low dead-space needle and syringe combination. It has less than half the dead-space of a reduced dead-space syringe.

The fourth image is a 1ml fixed needle syringe. This has the lowest dead-space and can be called a ‘low dead space syringe’.

What are the benefits of low dead-space syringes?

If the dead-space between a syringe and a needle is reduced:

  1. Less drug injected by the person will be considered wasted in the space at the end of the syringe.
  2. Less room for infected material (blood and possible viruses) to be stored in the space (this only reduces the risk, infected blood can still be present).
  3. It is easier to clear out the potentially infected blood if a person does decide to clean and re-use it.
  4. Reduced need to flush the syringe which reduces the potential vein damage which can be caused.

Though it is always highly recommended to use a new syringe and needle each time a person injects, we know that some people do re-use equipment.  It is believed that if low dead-space syringes are cleaned and re-used then this lowers the risks involved.  It is important to know that low dead-space syringes can still contain viruses, therefore there are still risks present.

Who might be likely to re-use a needle and syringe?

There are many reasons a person may re-use drug injecting equipment.  People affected by homelessness may not have easy access to Needle and Syringe Programmes and may not have places to store a stock of injecting equipment. People who have purchased drugs late at night and have no stock of sterile equipment at home might also be at risk of re-using equipment.

What can we do to help lower the risks associated with re-using injecting equipment such as needles and syringes?

  • Choose the lowest dead-space syringe and needle combination.
  • When using needle and syringe services we should encourage people to take as much equipment as they may need to ensure they do not run out before they return for more.
  • Encourage the return of used equipment, the less used equipment there is, the lower the risk of re-use and sharing.
  • People should be encouraged to keep their equipment separate from others’. They can request syringes with different colored plungers or mark their equipment so they know which belongs to them.
  • Continue to encourage blood borne virus risk discussions by cascading up to date harm reduction messages, including infection and re-infection risks.
  • Encourage regular blood borne virus testing and make it easy to take a quick test in the room where needle and syringe provision is.

Where can I go to find out more information?

The project to develop this animation included Bristol Drugs Project service users as co-designers. The project was overseen by a steering group that included Bristol Drugs Project, Exchange Supplies, Public Health England, NIHR CLAHRC West and NIHR Health Protection Research Unit (HPRU) in Evaluation of Interventions.


Tony Mullaney, Hep C U Later Training and Development Coordinator