Guides

Know what you're ordering.

Plain-English guides to syringes, needles, vials, sharps bins and swabs: what the numbers on the box mean, which pack to pick and how to store and dispose of things properly. No medical advice, just the practical bits.

Guide 1 of 6 · 4 min read

Choosing between 0.3ml, 0.5ml and 1ml U-100 syringes

All three use the same U-100 scale. The difference is how far apart the unit marks sit, and that decides how easy the barrel is to read.

A U-100 syringe is marked in units rather than millilitres: 100 units fill 1ml, so a unit is 0.01ml on every size. The 0.3ml, 0.5ml and 1ml syringes all share that scale. What changes between them is how much barrel each unit gets, and so how clearly the marks can be read.

What each size holds

The 1ml barrel holds 100 units, the 0.5ml holds 50 and the 0.3ml holds 30. The barrels are close to the same length, so the smaller the capacity, the more space there is between the marks. On a 1ml syringe the marks are two units apart; on the 0.5ml they are a single unit apart; and on the 0.3ml BD Micro-Fine they are half a unit apart.

  • Good to know: the capacity is printed on every box and sachet as 0.3ml, 0.5ml or 1ml, and the scale on the barrel always ends at 30, 50 or 100.

Match the barrel to the volume you measure

A syringe is easiest to read when the volume sits somewhere in the middle of the scale rather than right at the top or bottom. A 0.3ml barrel gives the clearest reading for small volumes; a 1ml barrel gives headroom for larger ones. If a volume would fill a smaller barrel almost to the top, the next size up is the more comfortable choice.

The needle is the same on all three

Across the BD Micro-Fine range the fixed needle is 30 gauge and 8mm on every size, and across the FMS range it is 32 gauge and 8mm. Choosing a barrel size does not change the needle, so the two decisions are separate. The needle guide below explains what those numbers mean.

  • Good to know: all three BD sizes are the same price per pack, so the size you pick doesn't change what you pay: 10 for £9.99, 50 for £19.99 or 100 for £29.99 (30p each).

These guides describe the products we sell: what they are, how they differ, and how to store and dispose of them. They are not medical advice and do not cover how, whether or when to use anything. For questions about a medicine or treatment, speak to a pharmacist or healthcare professional.

More guides

What needle gauge and length mean: 30G vs 32G, 8mm Guide 2 of 6 · 3 min read

Gauge is thickness, and the number runs backwards. Length is in millimetres. Here is how to read the "30G × 8mm" printed on a box.

Every fixed-needle syringe is described by two numbers: the gauge, which is the outside diameter of the needle, and the length from hub to tip. Both are printed on the box and on each individual wrapper, so you can check them before you open anything.

Gauge: a higher number means a finer needle

The gauge scale runs the opposite way to what you might expect. A 30G needle is about 0.30mm across, a 32G is about 0.23mm, and the 21G needle supplied with our 5ml syringe is about 0.8mm. So 32G is the finest of the three and 21G is the widest. The two gauges we stock on fixed-needle syringes are 30G (BD Micro-Fine) and 32G (FMS).

  • Good to know: gauge is written as a number followed by G. It describes the needle, not the barrel, so a 1ml and a 0.3ml syringe can share the same 30G needle.

Length: 8mm is the short end of the range

Length is measured in millimetres from where the needle leaves the hub to its tip. Every fixed-needle syringe we sell is 8mm. By contrast, the detachable 21G needle packed with the 5ml BD Emerald syringe is 40mm (1.5 inches), because it is made for drawing up from a vial.

Thin-wall needles

The FMS 32G needle is thin-wall: the wall of the tube is thinner than on a regular-wall needle of the same gauge, so the bore inside is larger even though the outside is finer. Liquid passes through it with less resistance and the plunger moves more smoothly. The BD Micro-Fine 30G is the everyday standard; the FMS 32G is the finest needle we stock.

  • Good to know: if finer matters to you, compare the FMS and BD ranges side by side in Syringes and needles: the same three barrel sizes, a different needle.

These guides describe the products we sell: what they are, how they differ, and how to store and dispose of them. They are not medical advice and do not cover how, whether or when to use anything. For questions about a medicine or treatment, speak to a pharmacist or healthcare professional.

5ml syringes with 21G needles for drawing up Guide 3 of 6 · 3 min read

A bigger barrel, a luer slip tip and a separate needle. What a 5ml syringe is for, and how it differs from a fixed-needle U-100 syringe.

A 5ml syringe is not simply a larger U-100 syringe. It is marked in millilitres, the needle is a separate part that you attach yourself, and it is built for drawing up and transferring liquid rather than for fine measurement.

Millilitres, not units

The BD Emerald 5ml barrel is graduated in millilitres and fractions of a millilitre, with bold markings and a green plunger stopper that is easy to see against the scale. There is no U-100 scale on it, so it is not interchangeable with the 0.3ml, 0.5ml and 1ml syringes for measuring in units.

Luer slip and the separate needle

The tip is a luer slip: the needle hub pushes onto the tapered end and holds by friction, as opposed to a luer lock, which screws on. The 21G × 40mm needle comes in its own wrapper alongside the syringe, so it stays sterile and capped until you fit it. Leave the cap on until the needle is attached and you are ready to use it.

  • Good to know: each pack contains matched pairs: one needle per syringe, both individually sealed.

Why 21 gauge

At about 0.8mm across, a 21G needle has a wide enough bore to move liquid quickly and to pass cleanly through the rubber stopper of a sealed vial. In the UK colour code a 21G hub is green. Once the liquid is where it needs to be, the syringe and needle go into the sharps bin together as one piece.

  • Good to know: the 5ml syringe is sold in packs of 10, 20, 50 and 100. The 100-pack works out at 30p a syringe, half the per-piece price of the 10-pack.

These guides describe the products we sell: what they are, how they differ, and how to store and dispose of them. They are not medical advice and do not cover how, whether or when to use anything. For questions about a medicine or treatment, speak to a pharmacist or healthcare professional.

Storing sealed vials and using the 9-slot case Guide 4 of 6 · 3 min read

A sealed sterile vial stays sterile for as long as the seal is intact. Keeping vials upright, apart and out of the light is most of the job.

Our 2ml and 5ml vials are supplied empty, sterile and sealed: a chlorobutyl rubber stopper under an aluminium crimp cap. The stopper is a self-healing port, so the vial is closed to the outside world until the first time it is pierced. Storing vials well is mostly about protecting that seal and the glass.

Keep the seal intact

The crimp cap and the stopper are what keep the inside sterile. Leave the cap on until a vial is needed, and before using one check that the crimp is tight and the glass has no chips or cracks at the neck. A vial with a loose cap or damaged glass should be treated as unsealed.

  • Good to know: vials arrive in sealed packs of 5, 10, 20 or 50. Once a pack is open, keep the unused vials in a closed container rather than loose.

Upright, apart and out of the light

Type 1 borosilicate glass is tough, but it is still glass, and vials that roll around in a drawer chip each other at the neck. Keep them upright so nothing rests against the stopper, keep them separated so they cannot knock together, and keep them out of direct sunlight. A filled vial should also be stored the way its contents require, which is a question for whoever supplied them.

What the 9-slot case does, and doesn't, do

The Compact 9-Slot case is an EVA hard shell with a high-density foam insert: six 16mm slots and three 22mm slots that hold vials upright and apart, a mesh pocket for small items, a double zip and a wrist strap. At 11 × 11 × 7cm it fits inside most refrigerators and travel bags. It does not cool its contents; if something needs to stay cold, the fridge does that job and the case keeps it organised.

  • Good to know: the case is free with every order over £50, or £14.99 on its own. Vials are not included.

These guides describe the products we sell: what they are, how they differ, and how to store and dispose of them. They are not medical advice and do not cover how, whether or when to use anything. For questions about a medicine or treatment, speak to a pharmacist or healthcare professional.

Sharps bins: sizes, fill lines, closing and disposal in the UK Guide 5 of 6 · 5 min read

What the 1 litre and 2 litre bins hold, where the fill line is, how the lid locks, and who takes a full bin away.

A sharps bin is a rigid, puncture-resistant container made to the BS EN ISO 23907 standard. Used needles and syringes go in whole, the lid locks shut when the bin is full, and the sealed bin goes to a clinical waste collection rather than into household rubbish. Here is how the two sizes we stock work.

1 litre or 2 litre

The 1 litre Sharpsguard has 0.84 litres of usable space and suits occasional use and a small shelf. The 2 litre Sharpsafe holds around 120 used 1ml syringes and has a translucent lid, so you can see how full it is without opening it. Both are yellow-lidded, CE marked and have the same two-stage lid.

  • Good to know: keep the bin where the syringes are used, so a used needle never has to travel across a room to reach it.

The fill line and the two lid positions

Every bin has a fill line moulded into the side. Stop filling when the contents reach it; the lid needs room to close and lock. The lid has a temporary position that shuts the bin between uses but can be reopened, and a permanent position that snaps and locks for good. Never force anything through the aperture, and never try to retrieve anything that has gone in.

  • Good to know: needles and syringes go in as one piece. Do not recap, bend or remove a needle before dropping it in.

Getting rid of a full bin in the UK

Once the lid is locked, write the date on the label. A sealed sharps bin counts as clinical waste and must not go in household waste or recycling. Most local councils run a sharps collection for households, some free and some for a small charge; the council's website will say how to book it. Some GP surgeries and pharmacies will also accept a sealed bin. Until it is collected, keep it closed, upright and out of reach of children and pets.

These guides describe the products we sell: what they are, how they differ, and how to store and dispose of them. They are not medical advice and do not cover how, whether or when to use anything. For questions about a medicine or treatment, speak to a pharmacist or healthcare professional.

Alcohol swabs and skin-prep basics Guide 6 of 6 · 2 min read

What a 70% isopropyl alcohol swab is for, why that concentration and not a stronger one, and how to keep a box effective.

An Alcotip swab is a small non-woven pad soaked in 70% isopropyl alcohol and sealed in its own foil sachet. It is used to clean a patch of skin before an injection. It is a simple product, and the one way to get it wrong is to let the alcohol dry out before it is used.

Why 70% and not 100%

Seventy per cent is the standard disinfecting strength for isopropyl alcohol. The water in the mix slows evaporation and keeps the alcohol on the skin for long enough to do its job; a purer alcohol flashes off too quickly. That is why every swab in the box is 70% IPA, and why the concentration is printed on each sachet.

One sachet, one wipe

Each swab is individually wrapped, so the rest of the box stays sealed until it is needed. Tear the sachet open, wipe the area once, and let it dry on its own. Wiping it dry or blowing on it cuts the time the alcohol has to work. A swab is single use; once it has touched skin it goes in the bin.

  • Good to know: a dry swab is one that has been opened, or whose sachet is damaged. Discard it and take another.

Storing a box

Alcohol is stable in a sealed sachet and gone within minutes from an open one. Keep the box closed and away from heat, and use older boxes before newer ones. A box of 100 lasts a long time at one swab per use, and the larger packs bring the price down to a few pence a swab.

  • Good to know: swabs are sold by the box of 100: a single box, 2 boxes (200) or 5 boxes (500). The 500 pack works out at 4p a swab.

These guides describe the products we sell: what they are, how they differ, and how to store and dispose of them. They are not medical advice and do not cover how, whether or when to use anything. For questions about a medicine or treatment, speak to a pharmacist or healthcare professional.

Still unsure which one to order?

The Help page covers delivery times, returns on sealed items and what to do if something arrives damaged. For anything else, email support@mediverified.com and we'll point you at the right product.

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