Quick facts
- A laboratory sealing film such as Parafilm is a stretchable, waxy film used to close flasks, tubes, plates and containers at the bench.
- It is a consumable, not a device. Neither the United States nor Canada names a sealing film in its device rules.
- Where such a film is promoted for a specific medical use it can be caught by 21 CFR 862.2050, the general-purpose laboratory equipment entry at Class I.
- In Canada a laboratory consumable that is not intended for a medical purpose is not a device at all; where an article is an IVDD, Rule 8 puts all other IVDDs at Class I.
- A sealing film and paraffin wax are different materials with different jobs; the names are often used loosely and should not be treated as one article.
- The entries and rule text below were checked against the current eCFR text and the Regulations on 2026-10-07.
A laboratory sealing film is the stretchy film a technician pulls over the mouth of a flask, a tube rack or a microplate to keep the contents in and the air out. It is bought by the roll and thrown away after use. It is not a device in either country, and that is the short answer to the question most buyers ask — but the reason it is not a device, and the narrow cases where the answer changes, are worth setting out because the same rulebook catches the things a bench keeps next to it.
What is Parafilm and how is it different from paraffin wax?
"Parafilm" has become a generic name for a family of thermoplastic sealing films made from a blend of wax and polyolefin that stretches to several times its length and seals to itself with hand pressure. It is flexible, slightly tacky and moisture-resistant. A laboratory may also keep paraffin wax, which is a different material with a different job: a hard wax used in histology to embed tissue and support it for sectioning, and in some laboratories as a coating. The two share a name family and nothing else.
| Item | Sealing film | Paraffin wax |
|---|---|---|
| Form | Thin stretchable film on a roll | Blocks or pellets of solid wax |
| Job | Close a container, seal a plate, hold a lid | Embed tissue, support a block for sectioning |
| Reused | No; single use per seal | Reused in the embedding bath until replaced |
| Bench | Any bench that seals containers | Histology and pathology benches |
| Device status | Consumable; not named as a device | Consumable; processed tissue is not a device |
Because the two are unrelated, a purchasing line that says "paraffin" can mean either, and a buyer who orders the wrong one gets a roll that will not seal a plate or a block of wax that will not stretch. Keeping the two lines separate is the first step in getting the order right.
How do Canada and the United States treat a laboratory sealing film?
Neither country names a sealing film. The practical question is whether the article is intended for a medical purpose, and in both countries the answer usually is no.
| Point | Canada | United States |
|---|---|---|
| Named entry | None | None |
| Status of a plain sealing film | Not a device | General laboratory supply |
| If promoted for a specific medical use | Assessed against the intended use | 21 CFR 862.2050, Class I |
| If part of an IVD kit | Treated as an IVDD; Rule 8 puts all other IVDDs at Class I | Assessed with the IVD it is packaged with |
| Basis of the class | Intended use recorded for the product | The use the product is promoted for |
| Records | None for a consumable | None for a consumable |
In the United States the openFDA device classification API lists 21 CFR 862.2050 for general-purpose laboratory equipment labelled or promoted for a specific medical use, and the entries under it sit at Class I. A sealing film that is sold to seal a plate makes no such claim and stays outside the entry. A film sold as part of a medical test kit takes on the character of the kit it belongs to. In Canada the same logic runs through the Medical Devices Regulations: a product is a device only if it is intended for a medical purpose, and an in-vitro diagnostic article that is not caught by the transmissible-agent or patient-management rules falls to Class I under Rule 8.
Does a sealing film ever become a device?
It can, in one narrow way. If a film is packaged as a component of an in-vitro diagnostic kit, or if it is promoted to be used in the performance of a medical test, it is assessed with the kit rather than as a stand-alone supply. That is a packaging and claim question, not a material question: the same film on the same roll can be a general supply when sold by the box and a component when sold inside a test kit. A buyer who is ordering for general bench use can rely on the plain answer, and a buyer who is assembling a kit should keep the film with the kit's documentation.
Which standard covers sealing a plate?
Standards for the bench cover the practice rather than the film. ISO 15189:2022 sets the quality and competence requirements for medical laboratories, including how samples and plates are handled and how records are kept, and the WHO Laboratory Biosafety Manual sets out the containment and handling practice for cultures. The WHO Laboratory Quality Management System handbook and the CLSI standards cover the bench procedures a laboratory follows when it seals, incubates and reads a plate, and the Public Health Ontario test index sets the acceptance rules a sample has to meet before it is plated.
| Element | What the standard covers | Why it matters at the bench |
|---|---|---|
| Handling | Sample and plate handling under ISO 15189 | A mislabelled plate is a rejected sample |
| Containment | Culture handling under the WHO manual | Sealing limits aerosol and spill risk |
| Records | Bench records under ISO 15189 | A sealed plate with no record cannot be traced |
| Acceptance | Specimen rules in the PHO index | A plate sealed before acceptance is wasted |
Which consumables sit on the same bench?
A culture bench restocks as a set. The sterile graduated 90 mL specimen cups carry the sample in from the collection point, and the double-tipped cotton swabs are the collection item used before a plate is streaked. Where samples are transported off site, the specimen transport containers move with them, and a laboratory that also monitors its own steriliser pairs the sterilization monitoring collection with the 24-hour monitoring five-pack trial. Laboratories and multi-site groups ordering at case level use the wholesale ordering page, and the B2B wholesale collection lists the lines held for institutional buyers. Reselling? become a distributor.
How is a sealing film used at the bench?
The film is stretched over the opening, pressed down at the edges and left in place until the container is opened. It holds a lid on during shaking, keeps a plate from drying out, and stops a spill from spreading if a container is knocked over. It is not a sterile barrier and it is not a seal for transport; a sample that leaves the building travels in a specimen container with its own closure. Keeping that difference clear matters because the film is often pressed into jobs it was not made for, and a transport that relies on a stretch film is a transport that can leak.
Sources
- 21 CFR 862.2050, General purpose laboratory equipment labelled or promoted for a specific medical use
- openFDA device classification API
- Medical Devices Regulations, SOR/98-282, full text and Schedule 1
- Health Canada, medical devices
- ISO 15189:2022, medical laboratories, requirements for quality and competence
- ISO 13485:2016, medical devices quality management
- ISO 14971:2019, risk management of medical devices
- World Health Organization, laboratory biosafety manual
- World Health Organization, laboratory quality management system
- CLSI, clinical and laboratory standards
- CLSI standards and products
- Public Health Ontario, laboratory services test information index
- College of Medical Laboratory Technologists of Ontario
- Institute for Quality Management in Healthcare
- CCOHS, OSH answers
- Standards Council of Canada
- US FDA, medical devices
- Public Health Ontario, infectious diseases
Where a plate or reagent receipt is recorded
A bench that does not write down what it opened cannot show when a lot changed. The printable media and lot receipt log is a blank form with columns for the item, the lot, the date received and the first use, so a failing lot is visible on the day rather than at the next review. The media log generator on the same page sizes the form to the number of benches a laboratory runs. No account and no sign-up are needed to open either one.
Every laboratory layout is different. Ask a compliance specialist and you will get a written answer specific to your equipment and province, with the regulation or standard it is based on cited.
Related reading
- Culture media, differential and selective, in Canada vs the US: which rules
- Agar plates in Canada vs the US: which media standard
- Specimen acceptance criteria in Canada vs the US: which rules
CliniEco Medical supplies eye care, laboratory and dental consumables of the kind described in this article. MDEL #35334. This article is written for optometry, laboratory and procurement professionals and is not legal advice; the class of a device and the records kept by a clinic belong to the manufacturer and to the requirements that apply to it.
Frequently Asked Questions
Is Parafilm a medical device?
No. A laboratory sealing film is a consumable and neither country names it in its device rules. It becomes part of a device only where it is packaged or promoted as a component of a medical test kit.
What is Parafilm made of?
It is a stretchable thermoplastic film made from a blend of wax and polyolefin that seals to itself with hand pressure. It is moisture-resistant and is not a sterile barrier.
Is Parafilm the same as paraffin wax?
No. Paraffin wax is a solid wax used to embed tissue for sectioning. Parafilm is a flexible sealing film. They share a name family and nothing else.
Which US entry can catch a sealing film?
21 CFR 862.2050 covers general-purpose laboratory equipment labelled or promoted for a specific medical use, at Class I. A film sold for general bench sealing makes no such claim and stays outside the entry.
How does Canada treat a laboratory sealing film?
A product is a device in Canada only if it is intended for a medical purpose. A plain sealing film is not a device; where an article is an IVDD and no earlier rule applies, Rule 8 puts all other IVDDs at Class I.
Can a sealing film be used to transport a sample?
No. It is not a sterile barrier and not a transport closure. A sample that leaves the building travels in a specimen container with its own closure, under the specimen acceptance rules of the receiving laboratory.
Which standard covers sealing a plate?
ISO 15189:2022 covers laboratory quality and competence, and the WHO Laboratory Biosafety Manual covers containment and handling of cultures. The sealing film itself has no device standard because it is not a device.
Where should a media or reagent receipt be logged?
The printable media and lot receipt log at the compliance log centre has columns for the item, lot, date received and first use, and the media log generator on the same page sizes the form to the number of benches a laboratory runs.
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