ISO 8362-6: Aluminium-Plastics Combination Caps for Injection Vials

ISO 8362-6 is the international standard that specifies aluminium-plastics combination caps for injection vials, defining their forms, dimensions, and requirements. These are the combination (combi) seals, an aluminium shell with a moulded plastic top, that crimp over the rubber stopper and the vial neck, the family that includes flip-off seals. It is Part 6 of the ISO 8362 series, “Injection containers and accessories.” The current edition is ISO 8362-6:2010. The standard ensures these caps are dimensionally compatible with the vials and closures covered by the other parts of the series.

This guide explains what ISO 8362-6 covers, how an aluminium-plastic combination cap is built, how it fits the ISO 8362 series, and how it differs from the related Part 7.

Key takeaways

ISO 8362-6 specifies aluminium-plastics combination caps for injection vials: the aluminium-plus-plastic combination seals, including flip-off designs.
It is Part 6 of the ISO 8362 series; the current edition is ISO 8362-6:2010.
A combination cap is an aluminium-plastic seal: an aluminium shell crimped over the stopper, with a moulded plastic top that flips or lifts away to expose the injection point.
ISO 8362-6 ensures the cap is dimensionally compatible with the vials of ISO 8362-1 and the closures of ISO 8362-2.
It is closely related to ISO 8362-7, which covers combination caps without an overlapping plastics part.
The cap’s job is to crimp over the stopper and hold it compressed against the glass, maintaining the container closure system seal.

What is ISO 8362-6?

ISO 8362-6 is the part of the ISO 8362 series that defines the aluminium-plastics combination caps used to seal injection vials: the aluminium-and-plastic seals that crimp over the rubber stopper. It is published by the International Organization for Standardization (ISO), and the current edition is ISO 8362-6:2010.

An aluminium-plastics combination cap is the type of seal most people picture as a flip-off cap: a thin aluminium shell that crimps around the vial neck over the stopper, topped by a moulded plastic disc or button. The plastic top gives a colour-codeable, easy-open surface; the aluminium underneath does the mechanical crimping. ISO 8362-6 standardises the forms and dimensions of these caps and the requirements they must meet, so that a combination cap from one manufacturer fits a vial and stopper conforming to the corresponding parts of the series. How this seal actually works mechanically is explained in how flip-off caps work.

What ISO 8362-6 covers

ISO 8362-6 covers the types, shapes, and dimensions of aluminium-plastics combination caps for injection vials, with the requirements those caps must meet. In broad terms it standardises:

Cap forms and dimensions. The geometry of the aluminium shell and its plastic top, dimensioned so the cap fits over the seated stopper and crimps under the vial neck flange.
Size designations. Caps sized to the common vial neck finishes (for example 13 mm and 20 mm) so they pair with the corresponding vials and closures.
Requirements. Material and construction requirements for the combination cap, including how the aluminium and plastic parts are assembled.

The standard exists so the cap fits and crimps reliably. A cap that conforms to ISO 8362-6 will seat over a stopper conforming to ISO 8362-2 in a vial conforming to ISO 8362-1, and crimp cleanly on a capping line.

How an aluminium-plastic combination cap is built

A combination cap is made of two parts working together: a formed aluminium shell that does the crimping, and a moulded plastic top that provides the easy-open, colour-codeable surface. The aluminium shell covers the top of the vial and extends down as a skirt around the neck; during capping its lower edge is rolled under the vial neck flange, compressing the stopper to form the seal. The plastic top sits over the centre and is designed to flip or lift away to expose the injection point, while the aluminium stays crimped.

Because the plastic top separates at a moulded line and cannot be reseated, the cap also provides tamper evidence. The flip feature comes in sub-types (button, bridge, and flower or scoreline), which differ only in the shape of the plastic, not in how the aluminium seals the vial. Those sub-types are compared in bridge-type vs button-type seals.

How ISO 8362-6 fits the series and relates to Part 7

ISO 8362-6 and ISO 8362-7 both cover aluminium-plastics combination caps; the difference is in the construction of the plastic part. Part 6 covers the combination caps in which the plastic part overlaps or covers the aluminium, while ISO 8362-7 covers caps where the plastic part does not overlap the aluminium (its full title is “Injection caps made of aluminium-plastics combinations without overlapping plastics part”).

Part	Scope
ISO 8362-1	Injection vials made of glass tubing
ISO 8362-2	Closures for injection vials
ISO 8362-3	Aluminium caps for injection vials
ISO 8362-5	Freeze drying closures for injection vials
ISO 8362-6	Caps made of aluminium-plastics combinations
ISO 8362-7	Aluminium-plastics combination caps without overlapping plastics part

Together with the plain aluminium caps of ISO 8362-3, Parts 6 and 7 cover the caps that finish a vial closure. All of them crimp over the stopper of Part 2 in the vial of Part 1 (or moulded-glass vial of Part 4), and all are dimensioned to be compatible.

How this works in practice at Autofits

Aluminium-plastics combination caps are Autofits’ core product. The FlipTop Optima flip-off seals are aluminium-plastic combination seals, produced in 13, 20, and 32 mm sizes and in several flip-feature sub-types: bridge type with a groove, bridge type without a groove, button type, and flower or scoreline type. The FlipTop range also includes Pull Ring and Tear Down combination seals; the full set is on the products page. The plastic disc is available in matte or glossy finish and can be printed and embossed, and the metal can also be coloured and printed. Production runs under an ISO 15378:2017 quality system, alongside ISO 9001:2015 and ISO 14001:2015 certification and a Drug Master File, in a 75,000 sq ft Nashik facility with an ISO Class 8 cleanroom and high-speed visual inspection for dimensional control. The full certification set is on the quality page.

Frequently asked questions

What does ISO 8362-6 cover?

ISO 8362-6 specifies aluminium-plastics combination caps for injection vials: the aluminium-plus-plastic seals (including flip-off designs) that crimp over the rubber stopper. It is Part 6 of the ISO 8362 series, “Injection containers and accessories,” and it standardises the caps’ forms, dimensions, and requirements so they are compatible with the vials and closures covered by the other parts.

What is the current edition of ISO 8362-6?

The current edition is ISO 8362-6:2010. ISO standards are reviewed periodically, so confirm the current edition and its requirements directly with ISO before relying on any specific clause.

What is the difference between ISO 8362-6 and ISO 8362-7?

Both cover aluminium-plastics combination caps. ISO 8362-6 covers caps in which the plastic part overlaps or covers the aluminium. ISO 8362-7 covers caps where the plastic part does not overlap the aluminium, with the full title “Injection caps made of aluminium-plastics combinations without overlapping plastics part.” The choice between the two constructions affects how the plastic top is formed, not how the aluminium crimps the stopper.

Is a flip-off seal covered by ISO 8362-6?

A flip-off seal is an aluminium-plastics combination cap, the type of seal ISO 8362-6 covers, where the plastic top overlaps the aluminium and flips away to expose the stopper. The exact part that applies depends on the specific construction of the plastic component, so a particular flip-off design should be checked against the precise scope of Part 6 or Part 7.

How is an aluminium-plastic combination cap different from a plain aluminium cap?

A plain aluminium cap (ISO 8362-3) is all metal. An aluminium-plastics combination cap (ISO 8362-6 or 8362-7) adds a moulded plastic top to the aluminium shell, giving an easy-open, colour-codeable surface that flips or lifts away while the aluminium stays crimped. Both crimp over the stopper to seal the vial; the combination cap adds the plastic flip feature and tamper evidence.

Sources

ISO: ISO 8362-6:2010, Injection containers and accessories, Part 6: Caps made of aluminium-plastics combinations for injection vials (https://www.iso.org/standard/52806.html)
ISO: ISO 8362-7:2006, Injection containers and accessories, Part 7: Injection caps made of aluminium-plastics combinations without overlapping plastics part (https://www.iso.org/standard/43551.html)
ISO: ISO 8362-2:2024, Injection containers and accessories, Part 2: Closures for injection vials (https://www.iso.org/standard/87251.html)

*Last updated: 2026-06-18. This article is general technical information, not regulatory or compliance advice; confirm current standard editions and requirements with ISO.*