Nitrile Glove Thickness in Mils: What 4 mil and 6 mil Actually Change
A clinic that switches glove suppliers notices thickness before it notices anything else. Staff who were comfortable in one box complain that the new ones feel flimsy, or that they cannot feel a vein, or that the gloves tear at the thumb during a dressing change. The number on the box - 4 mil, 5 mil, 6 mil - gets blamed for all of it.
Thickness is real, but it is one variable among several, and knowing what it does and does not control makes glove selection much less arbitrary.
What does a mil measure?
A mil is one thousandth of an inch, or 0.0254 mm. Examination gloves are usually quoted at the palm, which is why a 4 mil glove can feel thinner at the fingertips than the number suggests.
| Quoted thickness | Approximate wall | Where it usually fits | What it trades away |
|---|---|---|---|
| 3 mil | 0.08 mm | Short, low-contact tasks, food handling, quick checks | Tears sooner under abrasion |
| 4 mil | 0.10 mm | General examination, routine patient care, specimen handling | Middle ground on feel and durability |
| 5 mil | 0.13 mm | Busier clinical work, wet environments | Slightly reduced tactile feedback |
| 6 mil | 0.15 mm | Cleaning, instrument handling, heavier or rougher tasks | Least tactile feedback of the group |
The trade is consistent: more thickness buys abrasion life and loses sensitivity. For a task where you need to feel a pulse or palpate, a thinner glove helps. For a task where the glove meets a metal instrument edge, a thicker one lasts longer.
What else changes glove performance?
Four things carry as much weight as the mil figure.
Polymer formulation. Nitrile is not one material. Different formulations behave differently on elongation and on how quickly they relax once donned.
Film consistency. A glove with thin spots at the fingertips or the web of the thumb fails early regardless of its quoted thickness.
Fit. A glove that is too large bunches and snags; one that is too small over-stretches and thins at the knuckles. Getting the size right does more for durability than going up a mil.
The test specification. Standard examination gloves are made to a medical glove standard such as ASTM D6319, covering dimensions, tensile strength and water-tightness. That is a different question from chemical permeation, which is measured separately - for cytotoxic drugs, ASTM D6978.
How should a clinic choose?
Match the glove to the task and keep two thicknesses in stock rather than one.
| Task | Sensible choice |
|---|---|
| Routine examinations, specimen handling | 4 mil, standard exam grade |
| Chemotherapy or cytotoxic handling | A glove tested to ASTM D6978, in the size staff actually wear |
| Surface cleaning, instrument transport, waste handling | 6 mil heavy-duty |
| Long procedures with high tactile demand | Thinner glove with a verified fit, changed more often |
Two habits improve outcomes more than any thickness upgrade. First, change gloves on the schedule the task requires - a 6 mil glove worn for two hours carries the same contamination risk as a 4 mil glove worn for two hours. Second, fix fit before you fix thickness: a clinic that orders the correct size distribution gets fewer failures than one that simply buys heavier boxes.
For most Canadian clinics the practical line-up is a 4 mil standard exam glove at CA $7.99 per 100 for general care, and a 6 mil heavy-duty glove at CA $19.99 per 100 for cleaning and instrument handling. Clinics that also run a sterilizer can pair glove stock with spore-testing supplies - a five-pack biological indicator trial at CA $12.99 with shipping included is the usual starting point.
References
- CCOHS - gloves, personal protective equipment fact sheet (checked 16 September 2026)
- Public Health Ontario - infection prevention and control resources (checked 16 September 2026)
- National Center for Biotechnology Information - Bookshelf, infection control reference (checked 16 September 2026)
Ordering for a clinic, lab or care home? Wholesale and multi-site ordering covers case pricing and account setup, and the B2B wholesale collection lists the lines stocked for institutional buyers.
Related Reading
- Learn with CliniEco: glove selection, PPE and clinic supply guides
- Powdered vs powder-free gloves compared for clinical use
- Nitrile gloves for chemotherapy: what ASTM D6978 testing actually covers
- Nitrile examination gloves and clinic PPE
- clinic consumables
Frequently Asked Questions
Is a thicker glove stronger?
Not automatically. Thickness is one of several variables along with polymer formulation, film consistency and where the glove stretches. A well-made 4 mil glove often has better puncture resistance than a poorly made 5 mil glove. What thickness reliably changes is how long the glove survives abrasion and how much feeling you lose while wearing it.
What does 4 mil mean in millimetres?
A mil is one thousandth of an inch, which is 0.0254 mm. So a 4 mil glove wall is about 0.10 mm thick and a 6 mil glove is about 0.15 mm. The measurement is taken at the palm, and it varies across the glove - the fingertips are usually slightly thicker than the cuff.
Are exam gloves tested for chemical resistance?
Not all of them. Standard examination gloves are tested to a medical glove specification such as ASTM D6319, which covers dimensions, tensile strength and water-tightness - not chemical permeation. Gloves sold for chemotherapy handling are tested separately to ASTM D6978, which measures breakthrough time against a list of cytotoxic drugs. If staff handle cytotoxic agents, the glove selection has to follow that test, not the mil figure.
How should nitrile gloves be stored?
Cool, dry and out of sunlight. Heat and ozone degrade nitrile film, so a box left on a sunny windowsill or in a hot storage room ages faster than the expiry date suggests. Keep boxes closed, rotate stock, and never store gloves next to electrical equipment that produces ozone.
Last updated: September 2026. CliniEco Medical holds MDEL #35334 issued by Health Canada, and supplies clinics, long-term care homes and home-care programs across Canada.
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