Are zip-lock bags OK for sending specimens through pneumatic tubes?

Oct. 1, 2015

Editor’s note: Anthony Kurec, MS, H(ASCP)DLM, serves as Clinical Associate Professor, Emeritus, at SUNY Upstate Medical University in Syracuse, NY.

Q: We currently use our pneumatic tube station for sending specimens to the lab, meds from the pharmacy to nursing units, and clean supplies to nursing units. All lab specimens are placed in biohazard bags before being placed in the tube to the lab. The biohazard bags are reused if they do not appear contaminated or soiled. I am exploring a change to the process of the reuse of biohazard bags. I have been asked if zip-lock bags can be used inside the tubes instead of biohazard bags, as we practice Universal Precautions in the handling of all specimens. My understanding is that biohazardous materials need to be in a biohazard bag. Please comment on requirements of specimen containment and bag reuse. Thank you!

A: Pneumatic tube systems (PTS) have proven to be of great value in  providing prompt delivery of laboratory specimens and other materials as part of managing patient care. However, improper use and maintenance of a PTS can often cause delays in testing and wasted time for laboratory and nursing personnel in addition to potentially generating a biological hazard. Appropriate care in packaging potentially biohazard materials for transport through the system in a safe and intact manner is critical.The Occupational Safety and Health Administration (OSHA) has determined that most healthcare-associated infections (HAIs) are through direct contact, droplet, or airborne transmissions.1 Specimen leakage within a PTS can be one source of transmission. Significant delays with system shutdowns and decontamination procedures are time-consuming and costly. According to a report by the Centers for Disease Control and Prevention (CDC), associated costs with urban HAIs can be as much as $34 billion a year.2

Biological specimens must be appropriately contained during the pneumatic tube transport. OSHA says: Specimens of blood or other potentially infectious materials shall be placed in a container which prevents leakage during collection, handling, processing, storage, transport, or shipping.3

The CDC reiterates this: Breakage or leakage of specimens transported using a PTS risks contamination of the transport system itself.4

Section 3.1.6 of the same document states that specimens can be placed in a “sealed zip-lock bag” with a limit of one set of patient specimens per bag and placed in foam-padded carriers. It also notes that the intended bags to be used should be subjected to testing for leakage. Infection control guidelines outlined by a major manufacturer of PTS also recommends that each facility “validate the integrity of their sample and medication containers prior to use in pneumatic tube systems.”5

Patient requisitions must be kept in separate bags from specimens. OSHA further mandates that:

Warning labels shall be affixed to containers of regulated waste, refrigerators and freezers containing blood or other potentially infectious material; and other containers used to store, transport or ship blood or other potentially infectious materials, except as provided in paragraph (g)(1)(i)(E), (F) and (G).6

The container for storage, transport, or shipping shall be labeled or color-coded according to paragraph (g)(1)(i) and closed prior to being stored, transported, or shipped. When a facility utilizes Universal Precautions in the handling of all specimens, the labeling/color-coding of specimens is not necessary provided containers are recognizable as containing specimens. This exemption only applies while such specimens/containers remain within the facility. Labeling or color-coding in accordance with paragraph (g)(1)(i) is required when such specimens/containers leave the facility.7 

Another consideration is the composition of the bags to be used. Most commercially available biohazard bags are made of polyethylene or polypropylene, 1.5 to 2.0 mm thick and designed to meet or exceed the Dart Impact Resistance Test (165 gram dart impact).8,9 This test systematically measures various levels of puncture resistance. Information regarding results of this test for Ziploc™ bags is not readily available. (Personal communication, SC Johnson Company).

As a final note, reuse of zip-lock bags is not recommended.10 Continued integrity of the zip-lock seal is critical to preventing leakage issues. In addition, one cannot be fully assured that microscopic infectious contamination has not occurred. Micro-leaks can be a source of contamination to the PTS, staff, courier containers/cars, counter tops, and other areas that may have come into contact with an improperly sealed bag.



  1. Infectious diseases. Occupational Health and Safety Administration. Retrieved Accessed June 27, 2015.
  2. Scott II, R Douglas. The direct medical costs of healthcare-associated infections in US hospitals and the benefits of prevention. Division of Healthcare Quality Promotion National Center for Preparedness, Detection, and Control of Infectious Diseases Coordinating Center for Infectious Diseases Centers for Disease Control and Prevention. March 2009. Accessed June 27, 2015.
  3. OSHA 1910.130(d)(2)(xiii) Accessed June 27, 2015.
  4. JM Miller, Astles R, Baszler T, et al. Guidelines for safe work practices in human and animal medical diagnostic laboratories. MMWR Vol 61, supplement. Jan 6, 2012.
  5. Swisslog. Four critical procedures for infection control with a pneumatic tube system. Accessed June 27, 2015.
  6. OSHA 1910.1030(g)(1)(i)(A) Accessed June 27, 2015.
  7. OSHA 1910.1030(d)(2)(xiii)(A) 1910.1030(d)(2)(xiii)(A).
  8. ASTM International. Standard test methods for impact resistance of plastic film by free-fall dart method. D1709-03. Accessed June 27, 2015.
  9. Bel-art products.  Accessed June 27, 2015.
  10. Gile TJ. Reusing biohazard specimen transport bags. OSHA Healthcare Advisor. July 15, 2010. Accessed June 27, 2015.