Contact Sales on +44 (0)1472 240940

Berlin Packaging expands its presence in EMEA with the acquisition of BlueSky.

Images are for representative purposes only

GL18 White Closure with Integrated Dispensing Plug

  • Product Code: GL18W-IDP
GL18 white PP/PELD closure with integrated dispensing plug. Fits all GL18 bottles 5ml–100ml. Controlled flow dispensing. Ideal for essential oils, concentrates and professional-use formulations.
MOQ and lead time applies – Please contact us for further details
Enquire / Sample Request

The GL18 White Closure with Integrated Dispensing Plug (GL18W-IDP) is a PP/PELD screw cap incorporating a flow-control dispensing plug that sits within the cap body and works in combination with it as a single integrated assembly. When the cap is removed and the bottle is tilted, the dispensing plug restricts the bottle opening to deliver a controlled, metered flow of liquid — rather than the unrestricted pour of an open neck, or the drop-by-drop dispensing of a dropper insert. This makes it the appropriate dispensing format for applications where the user pours or flows a quantity of liquid in a controlled stream — including essential oils, concentrated aromatherapy preparations, professional-use personal care formulations, and household liquid products where measured, controlled dispensing is commercially preferable to an open neck. The cap and plug are applied and removed together as one piece, with no separate components to manage during filling, capping, or consumer use.

As a standard screw cap with no tamper-evident ring and no child-resistant mechanism, the GL18W-IDP is the most straightforward and accessible configuration in the GL18 dispensing plug family — appropriate for professional, trade, refill, and non-retail applications where tamper evidence and child resistance are not required. For retail applications where tamper evidence is commercially expected, the GL18TEW-IDP is the appropriate specification. For products where child access presents a safety risk, the GL18CRCW-IDP or GL18TECRCW-IDP provide child resistance with or without tamper evidence. As part of the GL18 system (also known as NW18 or DIN168), the GL18W-IDP is fully interchangeable across all GL18 glass dropper bottles in the BlueSky range — 5ml to 100ml, in both amber and clear glass. Contact BlueSky to confirm stock availability and MOQ details.

Additional information

Material

PP/PELD
Neck size

GL18

Integrated Dispensing Plug — Controlled Flow, Not Drop-by-Drop

The dispensing plug sits within the cap assembly and restricts the bottle opening to deliver a metered, controlled flow of liquid when the bottle is tilted — distinct from both the vertical dropper (which produces individual drops at 180° inversion) and the rim dropper (which produces drops at 45° tilt). This makes the dispensing plug the appropriate format for applications where the user pours or dispenses in a controlled stream rather than counting drops, and where an unrestricted open neck would result in excessive or uncontrolled liquid release.

Child-Resistant Mechanism — Household & Consumer Safety

The GL18CRCW-IDP features a child-resistant closure mechanism requiring a specific combination of actions to open — actions that young children are statistically unlikely to perform successfully, while remaining practical for adults. For consumer products containing essential oils, concentrated household liquids, or other formulations presenting an ingestion or contact risk to children, a child-resistant closure is the appropriate safety specification and may be a regulatory requirement depending on product category and market. Please contact BlueSky’s team to confirm the child-resistant certification status of this closure before specifying for regulated applications.

Cap and Plug Working Together — Single Integrated Assembly

The dispensing plug and child-resistant cap work as a combined assembly — the plug sits within the cap body and is not a standalone insert. This means the flow-control and access-restriction functions are integrated into a single component that is applied and removed as one piece, simplifying the filling and capping process and reducing the risk of component separation or misassembly during production or consumer use.

Three-Material Construction — PEHD, PP, PELD

The multi-material assembly is engineered for its specific functional roles: PEHD (high-density polyethylene) provides structural rigidity and chemical resistance in the inner cap body; PP (polypropylene) delivers the child-resistant opening mechanism; and PELD (low-density polyethylene) forms the flexible dispensing plug insert. All three materials offer broad compatibility with cosmetic, personal care, and household liquid formulations. Formulation compatibility testing is recommended prior to production, particularly for high-concentration essential oils, solvents, or chemically aggressive formulations.

Universal GL18 Compatibility — 5ml to 100ml

The GL18CRCW-IDP is compatible with all GL18 glass dropper bottles in the BlueSky range — 5ml, 10ml, 15ml, 20ml, 30ml, 50ml, and 100ml — in both amber and clear glass. The GL18 neck standard maintains a consistent inner bore diameter of 10.65mm ± 0.15mm across all bottle volumes, meaning this closure specification does not change when bottle size changes within the range. For light-sensitive formulations, amber glass provides UV protection that preserves formulation integrity over the product’s shelf life.

 

Dispensing Plug vs Dropper — Choosing the Right Insert

The dispensing plug delivers a controlled pour or stream — appropriate where the user dispenses by tilting and flowing rather than counting drops. The rim dropper delivers general drop-by-drop dispensing at 45° tilt, and the vertical dropper delivers precision drops at 180° inversion to ±10% accuracy. For applications requiring individual drop dispensing — whether precise or general — the appropriate dropper insert should be specified instead. Contact BlueSky’s team if you are unsure which dispensing format is most appropriate for your product and end-user experience.

  • Essential oils and concentrated aromatherapy blends
  • Household cleaning concentrates
  • Topical personal care
  • Oral liquid products
  • CBD and botanical oil preparations
  • Topical antiseptics and would care
  • Consumer wellness liquids

Delivery & Returns

Orders for products in our ‘In Stock’ ranges will normally be delivered within two working days. Our product ranges labelled as ‘Product MOQ Applicable’ may be subject to a lead time which will be confirmed to you when we receive your order. For information relating to delivery charges, please refer to the ‘Is there a carriage charge?’ section in our FAQs page.

In some instances, goods can be returned. Please view our full refunds policy in our terms and conditions here: Terms & Conditions.

Core Product Range

We endeavour to hold continuous stock of this product. We expect to stock these ranges for a significant period of time in the future. This ensures you can build ranges around them and rely on their availability both now and in the coming years.

In Stock

We hold these products in our UK warehouses for you and they are available for rapid delivery.

Product MOQ Applicable

These products are not currently available from our UK held stock. However, we can supply you from our flexible and solid, global supply chain. Please note that there are minimum order quantities (MOQs) associated with this product, and lead times may vary depending on the quantity ordered. For more information on MOQs and lead times, please contact: sales@blueskysolutionsuk.com

Additionally, we can create bespoke products for you whether through colour, decoration, or bespoke tooling - to your specification. Our team of product experts will work with you to understand your requirements and place the necessary orders.

Delivery & Returns

Frequently Asked
Questions

How does the dispensing plug work with the cap?

The dispensing plug is an integrated insert that sits within the child-resistant cap body — the two components work together as a single assembly rather than independently. When the cap is opened using the child-resistant mechanism and the bottle is tilted, the plug restricts the flow of liquid through the bottle opening, delivering a controlled stream rather than an unrestricted pour. The cap and plug are applied and removed together as one piece during filling, capping, and consumer use.

What is the difference between the dispensing plug and a dropper insert?

A dropper insert — whether vertical or rim — delivers liquid drop by drop, with the user typically counting drops to achieve a target dose. The dispensing plug delivers a controlled flow or stream when the bottle is tilted, making it more appropriate for applications where the user pours a quantity of liquid rather than counting individual drops. For precise pharmaceutical dosing, the vertical dropper (GL18CRCW-IVD) is the correct specification. For general drop-by-drop consumer dispensing, the rim dropper (GL18CRCW-IRD) is appropriate.

Does this closure meet child-resistant packaging regulatory requirements?

The GL18CRCW-IDP features a child-resistant mechanism designed to prevent access by young children. For applications where child-resistant packaging is a legal requirement — such as certain household chemical and medicinal products — please contact BlueSky’s team to confirm the certification status of this closure before specifying. Your regulatory advisor can confirm the applicable packaging legislation for your product category and market.

Does this closure also provide tamper evidence?

The child-resistant mechanism and any tamper-evident band are independent functions in the GL18 CRC closure system. Please contact BlueSky’s team to confirm whether a tamper-evident band option is available for this specific closure SKU. For products where both child resistance and tamper evidence are commercially or regulatorily required, confirming both functions at the specification stage is important before committing to production.

Ready to discuss
this product?

Our packaging specialists can advise on quantities, decoration options, compatible accessories and lead times. No obligation, just fast, expert advise

Enquire Now

What our customers say

Download our

2026 "The Wellness Revolution" Report

Sign up to receive...

the latest news, industry insights and advice straight to your inbox from our team at BlueSky.

Horizon House
Estate Road Five
Grimsby
DN31 2TG

+44 (0)1472 240940

My Account
Contact Us
About Us
FAQs
Brochures

Terms & Conditions
Privacy & Cookie Policy
Accessibility Statement
Modern Slavery Statement
Data Protection Policy
Terms of Use

Quality Policy
Environmental Policy
Health & Safety Policy
Sustainablity
More Policies

Linkedin-in Youtube
Enquire Now

Reminder, if ordering a sample of a bottle, don't forget to order samples of the closures you need and vice versa.

Sample Request

Reminder, if ordering a sample of a bottle, don't forget to order samples of the closures you need and vice versa.

Request Sample Pack

Please note: Free shipping is available to mainland UK addresses only. We review all requests and will reach out to you if we need any additional information before organising the shipment. Thank you for your interest!

Thank you, your form has successfully been submitted.

Thank you for your enquiry, whilst this is an automated message, we want you to know that we have received your enquiry and will be responding to you soon!

If there is anything you wish to discuss urgently, please contact us on +44 (0)1472 240940.

Back to Home