Black Plastic Tamper Evident Cap with Inner Dropper, 18/410

A ready-to-use closure for glass dropper bottles with an 18 mm neck (thread type 18/410) that handles both dispensing and tamper evidence in one. It consists of two parts: a transparent dropper insert that fits into the bottle neck and dispenses the contents drop by drop, and a black screw-on cap with a tamper-evident ring that seals the bottle and shows whether it has already been opened. The set is designed for contents dispensed in small quantities – essential oils, fragrance blends, oil serums, tinctures or concentrated active ingredients in an oil or alcohol base.

Both parts are declared as suitable for contact with cosmetic products; the declaration of conformity can be found in the product parameters.

How the set works

• Dropper insert – a transparent long-style component made of polypropylene (PP) that press-fits firmly into the bottle neck. When the bottle is inverted, drops fall one by one; the contents will not spill even with careless tilting and dosing is repeatable.
• Cap with tamper-evident ring – a black screw-on closure made of polyethylene (PE) with 18/410 thread. The ring visibly breaks and separates when first unscrewed, so both the customer and the producer can see that the packaging has not yet been opened. After opening, the cap remains fully functional, just without the ring.
• Black colour – the cap pairs well with amber, blue and clear bottles alike. Protection from light is provided by the dark glass of the bottle, not the closure.

Best suited for

• Essential oils and fragrance blends – drop-by-drop dispensing is standard here, since quantities are typically just a few drops. The tamper-evident ring also confirms the integrity of the packaging at the point of sale.
• Oil serums and facial oils in small packaging – the dropper dispenses smoothly with light to medium-viscosity oils; with thicker oils, flow is slower and it is advisable to test this in advance.
• Tinctures and alcohol extracts – thin contents flow from the dropper faster, so invert the bottle slowly and at only a slight angle.
• Samples and active ingredient concentrates – if you dose a raw material into a formulation drop by drop (for example, fragrance oils into soap or cream), the dropper replaces a separate measuring step.

The set is not suitable for thick gels and butter blends – they will not flow through the narrow dropper opening in any practical sense.

What is worth knowing about filling and use

Fill the bottle to its nominal volume, not to the brim. Once inserted, the dropper takes up part of the neck space and, if overfilled, will push the contents out, contaminate the thread and reduce the seal. The headspace between the nominal and total volume is intended precisely for the dropper and for the expansion of the contents with temperature changes.

Before first use, inspect the closure and if necessary rinse with isopropyl alcohol or ethanol and allow to dry completely; oil does not dispense well through a damp dropper. With concentrated essential oils, alcohol solutions and raw materials containing solvents, we recommend verifying the seal and plastic compatibility with the specific formulation, ideally with a short storage test in a horizontal position.

Both the dropper and the cap are made of commonly recyclable plastics (PP and PE); before recycling, simply separate them from the glass bottle.

Bottles with the same neck type and other ready-made packaging and closure combinations are available in the Handymade range. When combining with a bottle from another source, we recommend checking that the neck is genuinely 18/410 – a cap with a different thread will not seat properly and the dropper will not seal.

Frequently asked questions