Ballistic doors: ask the experts

Ballistic doors are used in an increasingly wide spread of building types. Our team works to provide you with the doors you need, to the standard you require, with the option to enhance the visual appeal of the door too – after the core product has been assembled. Here our team talks through some of the key component parts of designing and building ballistic doors.

How is the process of designing and manufacturing a ballistic door different to other kinds of personnel doors? 

Rhino’s ballistic doors have been designed and developed to enhance our security door range – building from selected products to upgrade elements and create a suitable ballistic door in line with the given requirements. 

Rhino already has CPNI (Central Protection National Infrastructure) accredited products, and we have developed a ballistic upgrade to our CPNI single personnel door set. 

Using this door set – which we already know to be a physically strong and robust door – we have developed a number of design modifications that we consider to be upgrades from the original CPNI design. By doing this, we have achieved a door set that is considered to satisfy a multi-threat terrorist attack. 

The door set now achieves CPNI MFES and a ballistic rating of FB4 (in accordance with EN 1522 and EN 1523) which satisfies criteria set out in the MTAS ‘Marauding Terrorist Attack Standard’. 

Marauding Terrorist Attacks | CPNI 

CSE Doors Chapter: Marauding Terrorist Attacks | CPNI 

Again, these doors are custom built – when designing ballistic doors, it is important to decide which ballistic grade/level you intend to design to – typically categorised by bullet type or size. 

Another consideration is which test standard you are going to comply with, while keeping in mind that a pass or fail result is based on a physical test and not a theoretical test. 

It is also worth noting that a ballistic standard could be client specified and doesn’t have to be based on a bullet type/size but could be based on other projectile threats, such as an IED ‘improvised explosive device’ or for a room that stores explosives. 

Ballistic doors differ from other door types, with specific elements designed to combat the identified threats, and there are many options within the ballistic door offering – our team will help you to identify what’s needed for your specific door(s).


Typically, what kinds of organisations require ballistic doors on their sites? 

The types of organisations that traditionally have required ballistic doors are those with buildings that are classified to be important to national infrastructure and those with cash handling facilities and many buildings with MoD establishments. 

However, in the current day, the threat has changed to include a wider spread of buildings – particularly in public areas where a ‘marauding terrorist’ armed with a gun can be a possible threat (large-scale venues, for example). 

Are ballistic doors required to be a particular size or thickness to be most effective? 

The true answer to the question is no, not really – it depends on which ballistic level you are aiming to achieve. 

There are some material thickness requirements dictated to us, set out within MoD documentation, however this only applies when manufacturing doors for the MoD and only when a client states that these standards apply. 

Testing helps to demonstrate the thickness of steel required for stopping different bullet holes, however there is more to consider: the types and layering of materials, for example. Using various layers of steel, or hardened steel, can also be effective, with some materials such as wood working well to absorb projectiles that fragment on initial impact. 

There are other lightweight, modern materials that should also be considered, although these do tend to be more expensive than traditional steel constructions. 

Another area that needs to be remembered, on top of the door thickness, is the design around the edge of the door frame and door leaf. The ballistic test house is permitted to inspect the door set prior to carrying out the test – essentially, looking for areas considered to be vulnerable, or of a weaker construction. 

For a product to achieve a full pass, it must not only stop the projectile but also prevent any splatter or spall passing the doors’ seals and onto the protected side of the door. 


What level of resistance do Rhino’s ballistic doors provide to customers? 

With guidance from CPNI, the threat here in the UK was deemed to be FB4 and FB2 in accordance with EN 1522 and 1523. Rhino’s door sample was subjected to the FB4 calibre bullets. 

This covers: 

FB4 Classification Calibre,  

FB4 – 0.44” Magnum FMJ/FN/SC & 0.357” Magnum FMJ/CB/SC 


FMJ = Full Metal Jacket  

CB = Coned Bullet 

FN = Flat Nose Bullet  

SC = Soft Core (Lead) 

NS = No Splinters 

Meanwhile, the Rhino Ultimate Personnel Door MK1 achieved Pass NS: 

The Ultimate Personnel Door MK1 offers FB4 levels of ballistic protection – and can be requested with or without fire rating. 

How is the level of ballistic protection rated, and are there specific regulations that manufacturers need to adhere to? 

In the UK, most manufacturers test to BS EN 1523: 1999 which sets out the requirements and the test procedure. 

Tests to BS EN 1523: 1999 have three possible outcomes: 

  • Fail – When the bullet perforates the sample.
  • Pass – Splinters “S” – When there is no perforation of the sample by the bullet, but there is perforation of the Witness Foil caused by splinters ejected from the rear face of the sample.
  • Pass – No Splinters “NS” – Where there is no perforation of the sample or Witness Foil.

Rhino achieved a Pass NS which is the best possible outcome we could have hoped for. 


Do ballistic doors require specialist forms of maintenance and upkeep? 

Ballistic doors at Rhino are subject to the maintenance that we uphold for all of our doors, with no particular specialist maintenance requirements. However, the door perimeter seals are a vital part of our Pass with ‘NS’ accreditation and therefore, these are rigorously checked during routine maintenance and associated inspections, looking out for any damaged or degrading seals that may need repairing. 


Can ballistic doors be modified to be aesthetically appealing or is there a standard specification that these doors need to follow? 

We believe we can make doors to the required standard and add additional elements to improve the visual aesthetic. 

Any additional layers, coatings, or veneers can be applied to the door leaves or frames to make them more aesthetically appealing. These must be additional layers and not layers that substitute any previous materials used in the tested and approved specimen. 

Although we are willing to incorporate aesthetic changes, all variations need to be noted and clients need to consider these to be a concession to the tested and approved product. 


Choosing the right ballistic door for your specific project and site is an important decision. Luckily, our experienced team is available to learn more about your needs and guide you through the process. If you’d like to learn more about our ballistic doors, here you can find a case study.