Plastic cap 28/410, child-resistant

The plastic cap 28/410 in a tamper-evident version is a screw closure made of polypropylene (PP) designed for bottles with a 28/410 neck finish. It is used to seal contents that are not dispensed with a pump or spray but poured directly from the bottle. The tamper-evident design provides additional protection against accidental opening.

The cap is primarily used for tonics, hydrolats, micellar waters, shower gels, shampoos, liquid soaps, massage and body oils and for refill packs that are decanted into smaller containers. The material is also suitable for direct food contact, making the cap useful in both cosmetics and the kitchen.

What the tamper-evident cap is suitable for

• Closure for storage and shipping – the solid screw cap has no dispensing opening or moving parts through which contents could leak. It is suitable for stock packaging and refill containers. It can also be used to seal a bottle that will be shipped, with the dispenser fitted by the customer upon arrival.
• Protection against accidental opening – the tamper-evident design is relevant for concentrated raw materials and preparations that should not be opened accidentally. We recommend testing the opening and closing mechanism on an empty bottle before filling.
• Cosmetics and food – the material is suitable for contact with cosmetic products and for direct food contact under normal conditions of use. The declaration of conformity is available on the product page.
• Neutral white colour – does not interfere with the label or the colour of the contents and suits both clear and coloured glass or plastic bottles.

Compatibility with bottles

The cap fits necks labelled 28/410. The first number indicates the neck diameter in millimetres and the second indicates the thread type. The same diameter with a different thread type, such as 28/400 or 28/415, may not seat or seal correctly. The neck type is listed in the specifications of each bottle.

Bottles with the same neck type and ready-made bottle-and-cap combinations are available in the Handymade range. For custom combinations, we recommend verifying the seal and the behaviour of the packaging with the specific formulation.

What to keep in mind when filling and using

• Preparation before first use – wash the cap in warm water with a mild cleaning agent, rinse, disinfect with isopropyl alcohol or ethanol and leave to dry completely. Residual water in the thread can reduce the microbiological stability of water-based products.
• Filling the bottle – the bottle is filled to the nominal volume, meaning the volume it is designed for under normal filling conditions. The total capacity to the brim is the physical volume up to the neck. The difference between the two is a reserve for the closure and for the expansion of contents when temperature changes. A bottle filled right to the neck may overflow through the thread when closed or when heated.
• Tightening – tighten the cap evenly and with care. An over-tightened thread seals worse than one tightened correctly. The bottle neck should be dry and clean before closing, especially when working with oils.
• Compatibility test with contents – when the formulation contains a high proportion of essential oils, fragrance compositions or solvents, we recommend running a test with the specific contents. After a few weeks, check whether the cap has changed in shape, colour or seal integrity.
• Recycling – an empty and clean polypropylene cap belongs in sorted plastic waste.

Frequently asked questions