What is a Safety-Engineered Syringe?

In short: The World Health Organization (WHO) uses terminology such as “smart” or safety engineered syringes, but understanding the differences between syringe types is not easy for the uninitiated person. We clarify some of these issues and provide the facts as stated by OSHA, FDA and other organisations.

This is the third in a series of blog posts on this topic. The previous two posts are:

“Smart” syringes: Safety engineered

The use of the term “smart” seems confusing to many of us. The World Health Organization (WHO) describes this as follows:

The New Smart Syringes
The surest way to protect against unsafe injections is to use devices for injections that have been engineered so they cannot be re-used and don’t lead to accidental needle stick injuries among health workers.

No Author (2016). WHO guideline on the use of safety-engineered syringes for intramuscular, intradermal and subcutaneous injections in health care settings. Retrieved June 25, 2017 from http://apps.who.int/iris/bitstream/10665/250144/1/9789241549820-eng.pdf?ua=1

According to the above, we prefer to use the term safety-engineered syringes instead of “smart” syringes. We can segment the global safety-engineered syringes market according to three therapeutic categories:

  1. auto-disable syringes,
  2. active safety syringes, and
  3. passive safety syringes.

We discuss these three product categories in more detail below. If you would like a general overview, check out:

Hogan Mitchel, Amber (2004). Defining passive in safety-engineered medical devices: A national overview. Retrieved July 1, 2017 from http://needlesticksafety.org/experts-speak-out/35-defining-passive-in-safety-engineered-medical-devices-a-national-overview

Sharps injury protection (SIP) feature syringes do sometimes have a built-in re-use prevention feature (RUP). But as the table below explains, things are not as easy as they seem at first glance (WHO guideline on the use of safety-engineered syringes for intramuscular, intradermal and subcutaneous injections in health care settings, 2016, see p. 10).

WHO wants exclusive use of the new safety engineered syringes by 2020

Safety-engineered syringes Description
1. Auto-disable syringes

The World Health Organization (WHO) sometimes calls these syringes re-use prevention syringes (RUPs).

These syringes are specifically designed for single use. They have some type of mechanism embedded that blocks the barrel once used, thereby assuring single-use of the needle.

Auto-disable syringes are the most popular syringes used for vaccination purposes.

Bottom line: Although manufacturers claim auto-disable devices can be retracted from within the patient, two problems arise:

  1. it takes considerable pressure on the plunger push button to activate the retraction mechanism, and
  2. it is difficult to do so without pushing the needle further forward into the flesh, which is not desirable for the patient.

For these reasons, in practice the auto-disable syringes currently on the market must first be withdrawn from the patient prior to activating the spring or vacuum mechanism. This raises two issues as outlined under item 3 below.

2. Active safety syringes These syringes require the health worker to activate the safety mechanism.

Active safety syringes are the most common type of safety-engineered syringes used across all healthcare sectors.

Bottom line: These syringes and blood collection devices are withdrawn from the patient prior to activating the safety feature. There is a risk that liquid may splatter or spill before safety mechanism can be activated by the health worker (see also below for more details).

3. Passive safety syringes Passive safety features remain in use before, during and after use of a syringe, but the definition is not straightforward. An example is a hollow-bore needle that has been designed to eliminate or minimize the risk of a skin puncture or needlestick injury to the worker.

These syringes require some action on the part of the user, the health worker, to ensure that the needle or sharp is isolated after use1.

Bottom line: Needlestick injuries occur mostly between the time when the contaminated needle is withdrawn from the patient and the time it is covered or retracted.

These devices tend to raise two concerns. For instance, when spring loaded syringes are retracted outside the patient, the following risks must be managed carefully:

    1. the needle moves so fast that there is liquid splatter that clings to the outside of the needle, as well as
    2. medication that remains in the needle may spill due to inertia and the back end of the needle not being sealed.

References used to put together the above Table

1 Occupational Safety & Health Administration, United States Department of Labor (2004 update 2015). Workbook for Designing, Implementing, and Evaluating a Sharps Injury Prevention Program. CDC/NIOSH. Retrieved July 1, 2017 from https://www.cdc.gov/sharpssafety/

Sepah Y, Samad L, Altaf A et al. Aspiration in injections: should we continue or abandon the practice? F1000Research 2014, 3:157. doi: 10.12688/f1000research.1113.3

Some helpful resources

In short, OSHA (the US Occupational Safety and Health Administration) points out that

Desirable Characteristics of Safety Devices include:

  • The device is needleless.
  • The safety feature is an integral part of the device.
  • The device is easy to use and practical.
  • The device performs reliably.
  • The safety feature cannot be deactivated and remains protective through disposal.
  • The devices work effectively and reliably, and are acceptable to the healthcare worker, and do not adversely affect patient care.

No Author (2016). Healthcare Wide Hazards Needlestick/Sharps Injuries. Occupational Safety & Health Administration (OSHA), United States Department of Labor. Retrieved July 1, 2017 from https://www.osha.gov/SLTC/etools/hospital/hazards/sharps/sharps.html#safer

The US Food and Drug Administration’s (FDA) Supplementary Guidance for Premarket Notification 510 (k) for Medical Devices with Sharps Injury Prevention Features identifies safety features as features that:

  • provide barrier between hands and needle after use on patient;
  • is integral part of the device and not an accessory;
  • remains in effect after use and during disposal; and
  • is as simple as possible, requiring little or no training to use effectively.

Have your say – join the conversation

Source: What is a Safety-Engineered Syringe?

  • Have you experienced the situation where splatter occurred, resulting in liquids clinging to the outside of the needle?
  • Do you know of an incident where a health worker was  injured by a needle?
  • How does your friend keep used needles safe – diabetes, etc.?

Looking forward to your comments.

PS. The video below points out succinctly why we need safety engineered syringes better today than tomorrow.



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