Policy on the Use, Storage, and Expiration of Substances, Agents, and Medical Materials Used in Animals

Institutional Animal Care & Use Committee
Sep 18, 2023 12:00 pm

This policy defines the expectations for the appropriate use, storage and expiration of agents, substances, and medical materials.

  • Purpose

    This policy defines the expectations for the appropriate use, storage, and expiration of agents, substances, and medical materials.

  • Applicability

    This policy applies to research, teaching, and testing activities involving animals, conducted under the auspices of the U-M, and applies to all locations under the purview of the U-M IACUC.

  • Glossary Definitions

    Non-Recovery Surgery

    A surgical intervention in which an animal is euthanized before recovery from anesthesia.


    This encompasses both of the following definitions:

    1. Local Anesthesia: Temporarily induces loss of sensation to a specific part of the body. May provide pain relief.
    2. Systemic Anesthesia: Temporarily induces loss of sensation with loss of consciousness. Only provides pain relief due to or during loss of consciousness.

    Expiration Date

    A date after which something must no longer be used.

    Items marked month/day/year are expired the next day (e.g., a drug marked 11/2/2020 is expired on 11/3/2020).

    Items stamped month/year are expired the first day of the next month (e.g., a suture marked 11/2020 is expired on December 1, 2020).

    Some medical devices or materials may have a production date, and not and expiration date. Users must follow the manufacturer’s directions regarding appropriate use timelines.

    Items that have been sterilized by laboratories should follow the Guidelines for the Storage of Sterile Items, which states that items will remain sterile indefinitely unless the packaging is damaged. 


    Agents are drugs intended for use explicitly as an anesthetic, analgesic, sedative, tranquilizer, and/or neuromuscular blocking agent (NMBA).


    Substances are all chemicals, drugs, experimental compounds, vehicles, etc. applied in or on an animal as part of the research activities, other than drugs used as anesthetics, analgesics, sedatives, tranquilizers, and/or neuromuscular blocking agents (NMBA).


    The number of days the manufacturer recommends the use of a product after first accessed (e.g., opened, punctured) or diluted.

    Common drugs that contain a use-by-date include carprofen, propofol and telazol.

    The use-by-date is often found in the package insert.

    Medical materials

    Consumable supplies used to assist in medical or research procedures. Examples include gauze, syringes, latex gloves, and catheters.

  • Policy

    Agents and Substances

    1. No expired substance or agent can be used as a stand-alone product or as a component of any dilution in an animal activity.
      1. Substances and agents expire in accordance with manufacturer recommendations. 
      2. If the manufacturer recommendations include an expiration date and a use-by-date, the substance or agent expires on whichever date occurs first.  
      3. Sterile bags of fluids accessed and connected directly to an animal through the use of an intravenous line have a use-by-date of 30 days after initial puncture.  
    2. Injectable agents and substances must be sterile and accessed aseptically. Review the Guidelines on the Preparation of Injectable Substances and Agents Administered to Animals for more information.
    3. Clearly label all substances and agents with their full name, concentration, and the relevant expiration or use-by-date.
    4. Store all substances and agents in accordance with manufacturer expectations, U-M requirements, and State of Michigan and DEA regulations.
    5. Clearly label expired items and segregate from non-expired items until they can be appropriately discarded.

    Medical Materials

    1. Expired medical materials and supplies can be used for non-recovery surgeries or non-recovery procedures provided that their usage does not adversely affect the animal’s well-being or potentially compromise the validity of the scientific study. These items must be:
      1. Clearly labeled (e.g., “Expired: non-recovery use only”).
      2. Segregated from non-expired items.
    2. Store all medical materials according to manufacturer recommendations.
  • Compliance

    The provisions of this policy are under the direction and oversight of the U-M’s IACUC. The IACUC will, if necessary, suspend research or implement sanctions if policy infractions should occur.   


    Scenario: Last day of acceptable use:
    The manufacturer guidelines for carprofen (stock bottle has an expiration of 8/5/2023) state the product must be used within 28 days of first puncture. The drug is first accessed on 5/2/2022 The remaining contents of the carprofen stock vial and all dilutions made from that vial cannot be used beyond 5/30/2022
    On 5/4/23 Ketamine (Ketamine stock bottle has expiration of 9/6/23) is diluted with Xylazine (Xylazine stock bottle has expiration of 10/6/23) for use as an anesthetic cocktail during surgery The dilution would expire when the first drug in the mixture expires. In this case, the Ketamine expires first. The mixture could not be used beyond 9/6/23.




For questions, additional detail, or to request changes to this policy, please contact the Office of the Assistant Vice President for Research, Director of the Animal Care and Use Office at acuoffice@umich.edu or (734) 763-8028.