Safety and Warnings

Safety and warnings

This is the page we'd ask you to read before your first session. It's short, it's specific, and nearly all of it exists because someone learned it the hard way. Nothing here is filler.

1. Read this first

What this product is

A MODTECH pen is precision hardware. It is a machined aluminum body, a glass cartridge and a click-stop dial. It dispenses whatever you put into the cartridge, at the amount you dial, and it has no opinion about what that is.

Everything ships empty. No substance of any kind is included with, prefilled into, or sold alongside any MODTECH product.

Research use only

These are not medical devices. They are sold for laboratory and research use only. They are not approved, cleared or intended for diagnosis, treatment or administration to humans or animals.

Nothing in this Help Center is medical advice, and nothing here should be read as instructions for administering any substance. What you load and what you do with it is entirely your responsibility, and you are responsible for complying with the law where you are.

2. Before every session

Inspect the hardware

Ten seconds, every time:

The glass. No chips, no hairline cracks, no cloudiness. Look at the rim in particular.
The cartridge holder. Clear, uncracked, threads clean.
The plunger. Straight, not bent, moving freely.
The dial. Clicking crisply and holding its position.

Anything that fails that check means stop, not “probably fine.”

Fresh tip, sealed cartridge

A new tip every session, and a cartridge whose pouch is still sealed. An intact CE / ISO 11607 pouch is what makes a cartridge sterile. A torn, damp or already-open pouch means that cartridge is out.

Open the pouch immediately before you fill, not in advance.

3. Sharps

Handling

Keep the outer cover on until the moment you need the tip exposed.
Never put your fingers near an exposed point to steady, guide or clear it.
Don't hand-recap. If a tip must be covered before disposal, use the outer cover and a one-handed scoop — never hold the cover in your other hand.
Take the tip off the pen when you're finished. A pen going into a fridge should not have a sharp on the end of it.
Work on a clear surface so an uncapped tip is never lost among clutter.

Disposal

Used tips and used cartridges go into a proper sharps container. Not household waste, not recycling, not a bottle or a jar, not a drawer.

Sharps containers are inexpensive and widely sold. When one is full, dispose of it according to your local rules — many pharmacies, clinics and municipal programs take them, and requirements vary by state and county.

Broken glass from a cracked cartridge goes in the sharps container too, not in a bin liner.

4. Never modify the pen

3D-printed parts, spacers and improvised adapters

Do not use 3D-printed spacers, adapters or replacement parts in a MODTECH pen. This one comes up often enough to deserve its own warning.

The reasoning, briefly:

Printed plastic isn't pressure-rated. Layer lines are structural weak points, and the plunger generates real force. A part that holds fine on the bench can split under load.
It can't be made sterile. Printed surfaces are porous and layered — they trap contaminants and can't be reliably cleaned or sterilized at home.
It can shed. Plastic particles and unreacted resin can end up in the fluid path.
The tolerances are wrong. Consumer printers don't hold the tolerances a sealing surface needs. “Close enough” in a sealed pressurised system means a leak or a stuck stopper.
A spacer is treating a symptom. If you need one, the cartridge is the wrong spec. Fix the cartridge, don't shim it.

Replacement cartridge holders

The cartridge holder is a wear part, and a cracked one does need replacing rather than tolerating — it's the component under pressure alongside the glass.

Replace it with a genuine holder for your pen generation, from us or from the original supplier. Do not substitute a holder from a different pen system, and do not print one. If yours is cracked and you can't source the right part, email us — that's a better outcome than an improvised fix.

Why this matters more than it sounds

Every part of this system between the plunger and the needle is under pressure during a dispense. A failure there isn't a part quietly not working — it's glass or plastic giving way with force behind it, next to your hands, with a sharp attached. That is the entire reason the rule is “no modifications” rather than “be careful.”

5. Glass

Chips and cracks

A chipped or cracked cartridge is finished. Not “usable if careful” — finished. Glass with a flaw in it fails suddenly and unpredictably under pressure, and a 3 mL cartridge is under pressure every time you press the pen.

Cold glass is also more brittle. If the pen has been in the fridge, handle it with that in mind and don't knock it against a hard surface.

Overfilling

3 mL is a hard ceiling. The stopper must stay inside the glass barrel. Pushed past the bottom edge, the cartridge won't seat properly and the pen can behave unpredictably afterwards.

If it happens, leave the syringe in and gently push the stopper back level with the bottom edge before removing anything.

Skipping the vent

Filling a sealed Classic cartridge without a vent compresses the air trapped inside until something gives — and what gives is the stopper, which exits the bottom of the cartridge with your solution behind it. Use a vent. The full procedure is on the loading page.

6. Single use

One tip, one cartridge

Pen tips	One session. The lubricant coating is spent and the point is no longer clean after a single use.
Cartridges	One fill. Don't wash, refill or attempt to re-sterilize — the sterile barrier can't be restored at home.
The pen body	Reusable indefinitely. Wipe the outside down; nothing should ever be soaked or submerged.

7. Storage

Where it lives

The pen, loaded: designed for refrigerated storage with the cartridge in place. It fits the fridge door.
Sealed cartridges: clean, dry, out of direct sunlight. The pouch is the sterile barrier — keep it dry and don't crush the box.
Never freeze anything, and don't leave the pen in a hot car or on a sunny windowsill.
No tip attached in storage.

Out of reach

Store the pen, cartridges, tips and your sharps container where children and pets cannot reach them. A fridge door is convenient, which also makes it accessible — factor that into where yours goes.

8. Stop and contact us

Stop using the pen and get in touch if:

The cartridge holder is cracked or the glass is chipped.
The plunger is bent, or the dial slips, skips or won't hold position.
It leaks from anywhere other than the needle.
Threads are damaged or cross-threaded.
Anything about it has changed and you can't explain why.

Email tfortech@modtechsupply.net. Everything is covered by the 30-day money-back guarantee, and a damaged pen is a replacement conversation, not a repair project.

9. Where to go next

Still stuck?

Email tfortech@modtechsupply.net. A real person answers within one business day, and that person is the owner.

MODTECH products are precision hardware sold for laboratory and research use only. They are not medical devices. No substances are included with or sold alongside any product, and nothing on this page constitutes medical advice or instructions for administering any substance to humans or animals. This page covers safe handling of the hardware and is not a substitute for the safety requirements that apply to whatever you choose to work with.