Sterile vs Nonsterile Ultrasound Gel: Buying for the Intended Procedure

Hospital buyers ordering ultrasound gel often see a single-use packet, a foil pouch, and a squeeze bottle treated as if the package shape were the specification. The same hospital may use gel for intact-skin imaging and for ultrasound tied to intravenous placement, biopsy, or an intraoperative exam. One undifferentiated line does not carry both jobs.

Buy by the labeled sterility claim and the intended procedure, not by the package format. Keep two requisition lines, and do not treat them as interchangeable. Line 1 is gel whose label says sterile, supplied in a single-use container, for the procedure categories below. Line 2 is gel that is not labeled sterile, as a single-use packet or a multi-use bottle, for routine imaging on intact skin, used with the handling rules in the storage section. A sterility assurance level of 10^-6 is a validation result to request for line 1. It is not printed on every pouch, and a small packet does not prove it.

Three documents are doing different jobs. The CDC safety alert of May 13, 2025 is advice to US healthcare providers, not a device regulation and not a change to a gel's cleared indication. The AIUM guideline, approved July 2, 2025, is a US professional statement. Its sterile-gel wording is "preferable" or "should be considered," depending on the setting. UKHSA guidance applies to England, was updated January 30, 2025, and says sterile single-use gel "should be used" in the settings it lists. A purchasing policy has to name which document it follows where those sentences differ.

The CDC alert's examples of percutaneous procedures are placement of central and peripheral intravenous lines, amniocentesis, paracentesis, tissue biopsy, and surgical procedures. The alert also says percutaneous procedures involve skin or tissue puncture and are not limited to that list. AIUM's examples of invasive procedures that pass a device through tissue include needle aspiration, needle localization, and tissue biopsy.

Where the three documents agree, stock line 1. Where they do not, the value-analysis record should name the document the hospital follows. Merging them into one unspoken rule hides the difference a buyer has to specify.

graph TD
    A["Ultrasound gel requisition"] --> B{"Which procedure or patient setting?"}
    B -->|"Category the adopted guidance reserves for sterile gel"| C["Line 1: single-use gel labeled sterile"]
    B -->|"Intact-skin imaging outside those categories"| D["Line 2: gel not labeled sterile"]
    C --> E["Request the 510(k) number, sterilization method, SAL evidence, and packaging validation"]
    D --> F{"How quickly is an opened bottle used?"}
    F -->|"High-turnover room"| G["Multi-use bottle: do not refill; date it on opening"]
    F -->|"Low-use area, isolation, or a precaution cart"| H["Single-use non-sterile packet, labeled non-sterile"]
    G --> I["If the policy follows UKHSA: discard when empty, at one month, or at expiry, whichever is first"]
    H --> J["Keep the packet visually distinct from the sterile line"]

Single-use describes the container and the discard rule. It does not describe sterility. A catalog can call a small container a packet, a packette, or a unit dose and still be selling non-sterile gel. The word to find on line 1 is sterile, plus the sterilization method in the technical file.

The December 11, 2025 MMWR report covers May 2023 through April 2025. Investigators identified 42 patients in the United States, Canada, and Israel with Paraburkholderia fungorum in clinical specimens, and 43 isolates from those patients. Whole-genome sequencing placed the clinical isolates and isolates from non-sterile ultrasound gel in one clone, with 0 to 10 single-nucleotide differences. Gel isolates came from six lots of two non-sterile brands, MediChoice and ClearImage, made by NEXT Medical Products Company. The CDC alert of May 13, 2025 names the lots known then: MediChoice 240302 and 240306, and ClearImage 230221, 230256, 240227, and 240230. The MMWR text reports six lots of those two brands and does not reprint that lot list, so the lot numbers belong to the alert.

MMWR says several facilities stocked single-use packets of non-sterile gel. That packaging might have been read as a marker of sterility and could have contributed to use before percutaneous procedures, including peripheral intravenous placement. The report calls this a possible contribution. It does not call the packet format the sole cause. Sixteen of the 42 patients had a documented ultrasound-guided percutaneous procedure before or during specimen collection, and gel use was confirmed for 15 patients. Ultrasound guidance is often missing from the chart, so those figures are not an exposure rate.

A bacteriostatic claim is a third label, separate from sterile and from single-use. The CDC alert says a label claim of "bacteriostatic" or "preservative," without a specific indication of sterility, should be considered non-sterile for clinical purposes. If a bid depends on the preservative, ask the vendor to name it. Do not copy the preservative system from another brand.

Parker Laboratories is a useful catalog example because the sterile and non-sterile lines are separate pages, and both pages use the word bacteriostatic. That is field structure, not a preference for this manufacturer and not evidence that the two gels are the same formula.

• Sterile Aquasonic 100, REF 01-01. The product page sells this configuration as sterile and single-use, in individually overwrapped sterilized foil pouches, and recommends it for procedures requiring sterility. That recommendation is the manufacturer's wording. The page does not publish pouch mass, sterilization method, sterility assurance level, acoustic values, or shelf life. Those fields stay unknown unless an instructions-for-use document or a clearance file supplies them. The current instructions for use cited on the page are PM-010-0002F (2023).

• Aquasonic 100, REF 01-20 and bottle configurations 01-02, 01-08, 01-34, and 01-50. This is a separate catalog line. The page does not use the word sterile. It does say bacteriostatic, and it says the gel is free from formaldehyde and parabens. Bottle volume, acoustic data, and shelf life are not on the page. Current instructions for use cited there are PM-010-0001H (2026) for the gels and PM-020-0001H (2025) for the single-use packettes. Do not describe the two lines as the same acoustic polymer. The pages do not say that.

Because both lines say bacteriostatic, that word cannot tell line 1 from line 2. Search the label and the instructions for use for sterile, and ask for the sterilization method. Marketing lines such as "acoustically correct" are not a substitute for the velocity, impedance, or attenuation values in a test report.

In the United States, acoustic coupling gel is not a separate therapeutic device and not a general hospital commodity with its own product code outside radiology. Under 21 CFR 892.1570, accessories to the diagnostic ultrasonic transducer may include "transmission media for acoustically coupling the transducer to the body surface, such as acoustic gel, paste, or a flexible fluid container." The transducer is Class II. The eCFR text is the current unofficial compilation; the annually published CFR is the official edition.

The FDA product-classification record for product code MUI, "media, coupling, ultrasound," is the identity to match against a vendor's paperwork. The procurement fields on that record are:

• Classification. Device class 2, Radiology review panel, regulation 892.1570, submission type 510(k). The record lists the product code as eligible for the 510(k) Third Party Review Program.

• Quality system. The record answers "GMP Exempt?" with No, so device quality-system requirements in 21 CFR Part 820 apply to the gel manufacturer. Since February 2, 2026, that part is titled the Quality Management System Regulation. The classification page does not list gel-specific environmental-monitoring or bioburden limits. Do not invent those limits from the word "not exempt."

• Recognized standards. The standards on the MUI page are ultrasonic-equipment standards, not gel chemistry or pouch tests: NEMA UD 2-2004 (R2009); IEC 60601-2-37 Edition 2.1 (2015) and Edition 3.0 (2024); and IEC 62359 Edition 2.1 (2017). Recheck the page before a tender. The record changes.

The K181363 summary states that, for acoustic coupling gels, there were no FDA device-specific guidance documents, no special-controls document, and no performance standards promulgated under Section 514, because these gels are accessories to diagnostic ultrasonic devices. That is a statement in a 2018 submission. The clearance letter's boilerplate still notes that a Class II device may be subject to additional controls. A contract should ask for the vendor's own 510(k) number. "FDA compliant" is not a clearance number.

K181363, cleared June 13, 2018, is the 510(k) for EcoVue sterile and non-sterile ultrasound gels from HR Pharmaceuticals. Product code MUI, regulation 892.1570, Class II. The configurations in the summary are a 20 g sterile single-use SafeWrap packet (REF 280), a 20 g non-sterile single-use packet (REF 281), and a 250 g non-sterile multi-use FlexPac pouch (REF 285). Use the file as a list of fields a buyer can request. The numbers are that file's reported ranges. Most were generated by the manufacturer's internal methods. Viscosity cites ASTM D445-17a. They are not pass/fail limits for other brands, and they are not a reason to treat two vendors' gels as interchangeable.

Read the indication before using the word sterile as if it widened the clearance. Both the sterile and the non-sterile EcoVue gels were cleared for the same use: intact skin during non-invasive medical ultrasound procedures, to couple sound between the patient and the imaging equipment. Clearance of the sterile SKU in this file is not clearance for percutaneous or other invasive use. The CDC alert is a safety recommendation about which gel to use for percutaneous procedures. It does not rewrite this indication. The summary also compares EcoVue with Sheathing Technologies' Sheathes sterile gel (K130041), sterilized with hot water, and Sheathes non-sterile gel (K112827). Sterilization method and shelf life in that comparison are product-specific.

If a sterile pouch arrives with visible damage, use the site's goods-receipt guide on recording sterile-pouch damage. Record the packaging level and the labeled identity. An undamaged-looking pouch is not, by itself, evidence that the gel inside is sterile.

If the vendor does not disclose attenuation and its frequency, the sterilization dose or other process parameters, or the package-aging method, mark the field unknown. Do not fill the blank with K181363's ranges or with another brand's catalog. Unknown means the tender does not yet have the fact.

Ultrasound gel is often sold under a distributor's brand. A lot-level recall that names only the factory brand will miss boxes that carry a private label. Receiving has to be able to find the lot under every name the hospital actually bought.

At goods receipt, capture the manufacturer, the brand printed on the box, the lot, the expiry, and the device identifier when the label carries a UDI. The site's guide to what receiving teams should capture for UDI and GUDID is the place for those label fields. For product code MUI, record the device identifier when a UDI is present. The brand "NDC" on the Eco-Med list is the distributor NDC Inc., not a drug-code field.

Quality agreements are where the hospital can require notice of a lot-level recall and a crosswalk from the factory lot to every private-label SKU on its purchase orders. The site's article on quality agreements for consumable suppliers covers purchasing information and change control. It does not create a universal 24-hour notice clause. Put the notice timing the supplier will actually meet into the agreement, and do not cite this recall as if that timing were already the law.

Line 2 is reasonable to buy when the units can follow the handling rules the facility adopts. AIUM and UKHSA do not write the same bottle rule, so the formulary note should name which document applies. UKHSA states a one-month opened-bottle limit. AIUM states refill, seal, upright storage, and tip-contact rules, and it does not state a calendar discard date.

Warming is optional, and the two documents limit how it is done. AIUM says dry heat should be the only method used to warm gel, and that warmers should be cleaned on the manufacturer's and the facility's schedule. UKHSA says warming is not recommended unless a clinical benefit outweighs room-temperature gel. Where gel is warmed, UKHSA says to use dry heat rather than warm water, and to keep bottles upright. UKHSA notes that water baths have been a contamination route for gel and other supplies.

Store gel under the conditions printed on the label or in the instructions for use. UKHSA says to follow the manufacturer's instructions and to keep gel in a dry area away from sources of contamination. If the label and the instructions for use state no temperature range, leave that field unknown. The site's article on labeled storage and transport is the method for logging the conditions the label actually states.

Use this list to write the item master and the bid request. It is a specification checklist. It is not a clinical protocol and not a ranking of gel manufacturers.

• Two item-master lines. Name them so the word sterile appears on line 1 only, for example "Gel, ultrasound, sterile, single-use" and "Gel, ultrasound, non-sterile." Limit line 1 ordering to the departments that perform the categories in the table, as infection control defines those categories for the hospital.

• Ask for the clearance and the method that was validated. Require the 510(k) summary for product code MUI and the indications-for-use statement. For the sterile line, require the sterilization method and the SAL evidence the vendor validated. Gamma irradiation and ISO 11137 are what K181363 used. Hot water is what that file's sterile predicate used. Set the bid condition to the method and the release evidence in that vendor's file.

• Ask for contact category, not a bare biocompatibility sentence. Request the ISO 10993 evaluation and the contact duration and tissue. K181363's acceptable results were for limited intact-skin contact. That does not answer mucous-membrane or breached-skin contact.

• Keep non-sterile packets from looking like sterile pouches. If the packages are the same size and color, separate the bins and put non-sterile on the line-2 label and the shelf. MMWR says manufacturers and facilities should make sure non-sterile gel, especially single-use packets, is clearly labeled non-sterile.

• Do not buy gel for decanting or refilling. Remove bulk-to-bottle refill packs from department templates, at whatever jug size the vendor uses for transfer.

• Write the opened-bottle date the adopted policy uses. If the policy is UKHSA, date the bottle on opening and discard it when empty, after one month, or at expiry, whichever comes first, and sooner if the manufacturer says so. If the policy is AIUM only, follow AIUM's refill, seal, upright-storage, and tip-contact rules, and do not pretend AIUM stated one month.

• Receive by identity and lot. Check that cartons are intact enough to read the label, and log manufacturer, brand alias, lot, expiry, and any storage conditions the label states. Log a temperature excursion when the label defines the limit that was crossed. For product code MUI, the receiving identity is the device identifier when a UDI is on the label, together with the lot and the brand.

Coupling gel is a transmission medium. It is not a barrier drape and not a treatment. The purchasing decision is which labeled product belongs in which procedure category, which document the hospital is following where the guidance differs, and which evidence fields are still unknown when the purchase order is signed.