Standards and watermist testing

Standards and Compliance

Automist Smartscan® has been independently, third party, tested by Exova Warrington Fire to confirm that it meets the performance requirements of BS 8458 2015, as validated by the BSI Verification Certificate VC 71258

Regulation to ensure the safety of buildings has rightly been under scrutiny since the Grenfell Tower tragedy. Forthcoming reforms to the building safety regulatory system are likely to implement all of the recommendations made by Dame Hackitt in her Independent Review of Building Regulations and Fire Safety, including placing greater accountability on those responsible for building safety. 

Building regulations are the legal requirements for all new and significantly altered buildings in the UK. The key thing to note is that they are functional i.e. performance based, rather than prescriptive. This means they state what the requirements are, they do not say how these requirements must be met.

British Standards and documents such as Approved Document B (ADB) provide guidance on how to achieve compliance, effectively providing a recipe (but not the only one) of common historical practices. However, as stated in ADB following the guidance in approved documents does not guarantee compliance with the requirements of regulation and such documents cannot cater for all circumstances, variations and innovations. 

The 2019 edition of Approved Document B states....

‘Although approved documents cover common building situations, compliance with the guidance set out in the approved documents does not provide a guarantee of compliance with the requirements of the regulations because the approved documents cannot cater for all circumstances, variations and innovations. Those with responsibility for meeting the requirements of the regulations will need to consider for themselves whether following the guidance in the approved documents is likely to meet those requirements in the particular circumstances of their case.

Note that there may be other ways to comply with the requirements than the methods described in an approved document…

Where the guidance in the approved document has not been followed… the person carrying out building works should demonstrate that the requirements of the regulations have been complied with by some other acceptable means or method.’

Sprinklers are the only means of active fire suppression referred to specifically in the current version of ADB because it is the oldest form of suppression, not because it is the best. Automist is currently outside the scope of existing Standards for sprinklers (BS 9251, BS 9252) and watermist suppression systems (BS 8458) so we have sought alternative ways to prove its effectiveness and compliance to the Building Regulations. Extensive testing has been conducted by Exova Warrington Fire, to confirm:

Smartscan qualifies by meeting the performance criteria in the relevant code of practice for fixed water mist fire protection systems: BS 8458: 2015 (BSi Verification Certificate - VC 712581). It is LABC Assured (EWS534B), previously Registered Details, and is deemed to be acceptable as a code-compliant automatic water fire suppression system, for example in accordance with the recommendations of BS 9991:2015.

The development of Automist Smartscan was steered by computational fluid dynamics modelling by the University of Greenwich’s Fire Safety Engineering Group. Once the design was finalised it was extensively tested and proven to deliver performance superior to the requirements of the British Watermist Standard (BS 8458), and even the performance of the widely used sprinkler standard (BS 9252).

Designing for the objective, not just the standards

Whilst we will continue to work with the relevant bodies to expand or create Standards to cover systems such as Automist, our primary aim remains to develop a suppression system that provides the best possible outcomes for the applications it is designed for. 

Beyond just compliance and standards, our watermist system is designed to maximise tenability (survivability) for the occupant in the room of fire origin. We do this by operating at the earliest time (up to two minutes before a traditional sprinkler) to minimise the production of toxic gases. We have tested the system to demonstrate it can outperform traditional approaches in several real-life scenarios - watch the videos

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Recorded or live (available anytime)

CE Marking requires manufacturers in Europe to declare that their products meet relevant product standards, ensuring that the products are safe. Because the Smartscan runs on electricity, assuring electrical safety and electromagnetic compatibility are important. Products without testing to validate their CE declaration can result in products that not only will not perform when required but which can be dangerous to occupants when installed.

CE Mark List of Standards that apply to Automist Smartscan to meet Low Voltage Directive, 73/23/EEC & FCC requirements:

  • BS EN 50130-4:1996 (+A1/A2) Alarm Systems: Electromagnetic Compatibility. Product family standard: Immunity requirements for components of fire, intruder and social alarm systems
  • BS EN 55014-1 Electromagnetic compatibility — Requirements for household appliances, electric tools and similar apparatus — Part 1: Emission
  • BS EN 55014-2 Electromagnetic compatibility — Requirements for household appliances, electric tools and similar apparatus — Part 2: Immunity
  • BS EN 60335-1 Household and similar electrical appliances — Safety — Part 1: General requirements
  • BS EN 60704-1 Household and similar electrical appliances – Test code for the determination of airborne acoustical noise
  • BS EN 61000-3-2 Electromagnetic compatibility (EMC) — Part 3-2: Limits — Limits for harmonic current emissions (equipment input current k 16 A per phase)
  • BS EN 61000-3-3 Electromagnetic compatibility (EMC) –– Part 3-3: Limits — Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems
  • BS EN 61000-3-11 Electromagnetic compatibility (EMC) Part 3-11: Limits - Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems
  • EN 61000-6-3 Electromagnetic Compatibility (EMC) – Part 6-3: Generic Standards Emission Standard for residential, commercial and light industrial environments

To comply with the Water Supply (Water Fittings) Regulations or Scottish Byelaws Third-party verification carried out by: Kiwa Ltd

WRAS (Water Regulatory Advisory Scheme) Approved Certificate no.1102330. Automist is WRAS approved for connection to the water supply.

Factory Production Control

Automist pumps and Smartscan heads are fully tested and validated for electrical and electronic integrity and operation; water flow; over-pressure safety switch operation and correct operation of controls, actuators, and sensors. Each carries a serial number which is logged in production and also by the installer on site so that they are fully traceable.

Automist Smartscan® has been independently, third party, tested by Exova Warrington Fire to confirm that it meets the fire performance requirements of BS 8458 2015. Although it is outside of the scope of the standard, this does not stop Plumis from demonstrating it is fit for purpose. 

For a more detailed breakdown of how Automist meets the requirements of BS8458 see below:

BS 8458 Requirement

Prescriptive or Performance?

Automist Smartscan Provision

Comment on Compliance

1. Scope
"watermist systems with automatic nozzles"


Does not use an automatic nozzle as described in the definitions "an integral quick-response
thermal release element" but system does function automatically using a thermal element on the heat detector

Uses an open nozzle configuration + automatic heat detector.  Complies with performance.

5. System actuation should be automatic by glass bulb or fusible link, initiated by heat.


System is actuated automatically by a heat detector.

Actuation is not by glass bulb or fusible link, but it is automatic and by heat. Complies with performance.

6.1 Fire Tests
When tested, nozzle should suppress fires for 10 minutes for domestic or 30 minutes for residential.


System runs automatically for  30 minutes until stop button on pump is pressed.

Complies with domestic and residential performance.

6.1 Fire Tests
Defines tests and performance criteria.


System has been tested appropriately and meets all performance criteria.

Complies with performance.

6.2 Limits of Application
Defines limits of applicability.
3.5m or 5.5m high
32m2 or 80m2


Tests a,b,c,d and e have been run so 3.5m high and 80m2 are tested limits. Due to nozzle height from wall, 5.5m high should not be an issue if there are no fire loads at 3.5m and above.

Limits to be verified on a case by case basis and Plumis to be consulted in case of doubt. A fire engineering evaluation may be required.

6.3 System Design
b) should be a wet pipe system.


System is a dry pipe system.

Does not impact performance and avoids risk of Legionella.

6.3 System Design
c) Thermally actuated nozzles should meet requirements for quick response in accordance with BS EN 12259-1.


System is actuated by a  double knock setup. Smoke and heat detector with less thermal inertia than a fusible link and then an infra-red thermopile sensor to validate the fire and determine its location. 

Prescriptive requirement not applicable to Automist.

6.4 Extent of Protection
all parts of the dwelling


System can be installed in as many rooms as necessary depending on objective. Partial protection is acceptable as a compensatory measure, elective safety enhancement or as part of a fire engineered solution.

Extent of coverage varies for any suppression system. Full coverage is common and best practice, but not mandated when fire engineering principles are followed. 

6.5 Hydraulic calculations


Automist is a pre-engineered system so hydraulic calculations are not required.

No requirement to comply. Pre-engineered design precludes the requirement.

6.6 Discharge Performance
Flow for 64m2 Area of Maximum Operation


This is a pre-engineered, electronically controlled system, so only one spray head activates, so no additional flow needs to be designed as no other spray heads will activate.

No requirement to comply.

6.7 Discharge duration should be 30 minutes for residential.


Discharge duration is 30 minutes or until stop button on pump is pressed.

Complies with requirement.

6.8.1 Water Supplies
Design should identify water supply requirements


Automist requires 1bar and 5.6lpm for 30 minutes. Dry pipe avoids Legionella risk.

Complies with requirement.

6.8.2 Water Supplies
water can be from mains supply boosted by a pump.


Automist is always supplied from a mains supply and boosted by its own pump.  No need for water tank due to low pump flow.

Complies with requirement.

6.8.4 Mains Water Supplies
Flow requirement of 64m2 plus 25lpm (domestic) or 50lpm (residential)


Priority valve not expected to be required in Automist installation due to its very low flow requirement. 6lpm install flow requirement to be validated as part of commissioning procedure.

Complies with requirement.

6.9 Backflow Prevention


WRAS approved backflow check valve included in every install

Complies with the performance requirement of avoiding backflow contamination.

6.10 Nozzle coverage and location
Spacing, positioning, height


Automist's different principle of operation requires different locations as per Technical Handbook which must be followed (always the case for pre-engineered systems, typical for watermist systems).

Alternative coverage and positioning permits proven fire suppression performance validated by third party testing. Compliance with prescriptive requirements is not necessary for performance.

6.11 Components testing and certification


Automist has been internally tested against relevant UL 2167 requirements to ensure component robustness. Third party certification testing in progress. 

Meets performance requirements through in-house testing. Pipes and Fittings


Automist accepts the use of stainless steel piping, as per standard or flexible hoses as per Plumis spec.

Complies with requirement. Valves


a) labelled stop valve is present upstream of pump
b) system test valve not required as open nozzle (system flow and integrity tested at nozzle)
c) drain valve not required as open nozzle (quick disconnect used for water purge)
d) alarm valve not required (alarm triggered electronically)

Complies with the requirements which are relevant and applicable.

6.11.4 Electrically operated devices
fire pump power supply


fused, fire resisting cable, from supply side of consumer unit used 

Complies with requirement.

6.11.5 System strainers


Strainer present upstream of pump

Complies with requirement.

6.11.6 Fire Pumps
Location, protection and automatic test


Location and protection requirements in Technical Handbook. Automatic churn of the pump is not possible on an open nozzle system.

Cannot comply with requirement because not a wet pipe system. Automist pump does not need to be churned to maintain reliability. 

6.13 Additives


No additives used

Not applicable.

7. Installation, commissioning and documentation


Frost protection only if water supply pipes to pump can freeze, remaining system is dry. System commissioning allows for full discharge, fire simulation test. Higher reliability than 7.2. Plumis warranty only provided when Commissioning Certificate sent to Plumis by authorised installer.

Complies and supersedes requirements.

8. Maintenance 


An Automist annual service consists of a full recommissioning of the system (alarm & discharge) as detailed in the Technical Handbook. 

Complies with intent of requirements through specific Plumis procedure.

Annex C. Room fire tests


System has been tested in accordance with requirements of Annex C and meets all performance criteria.

Complies with performance.



The LABC Assured process (previously Registered Detail) verifies the use of alternative products for other ways to comply with the Building Regulations.

The process strongly resembles certification, with every aspect of the product scrutinized not only for fire performance but also for its long-term reliability, maintenance, installation, documentation and training.

A Failure Mode and Effect Analysis document was prepared for Automist Smartscan. It allowed us to examine all potential sources of failure so that they could be anticipated and effectively addressed. System-level performance objectives (for example, to suppress fires in worst-case conditions) were also derived from this approach. The UL 2167-2004 Water Mist Nozzles for Fire Protection Service process was used to identify tests and procedures for component validation, while BS 8458:2015 and BS 9252:2011 were used as the basis for fire performance validation. The relevant UL 2167 tests have therefore been incorporated into this product design and validation methodology.

To demonstrate performance beyond BS 8458:2015, Plumis is seeking an internationally recognised certification which tests reliability as well as fire performance.

Under the standard, Automist Smartscan is defined as a sidewall, open nozzle, pre-engineered water mist system for residential applications. The relevant extracts are:

5.14 m) Sidewall – A nozzle which is designed to be installed adjacent to a wall.

5.14 i) Open – A nozzle without a thermosensitive element which discharges water mist.

5.19 PRE-ENGINEERED WATER MIST SYSTEM – A system having predetermined flow rates, nozzle pressures, volumes, discharge patterns, and spray flux densities. These systems have specific pipe sizes, pipe lengths, flexible hose specifications, number of fittings, and number and type of nozzles prescribed in the manufacturer design and installation instructions.

The relevant clauses from UL 2167 standard are set out below. OK means that the Automist Smartscan has been successfully tested or verified.

UL 2167 Clause



6 – General Construction


(6.2 and 6.5 not relevant because they only apply to open nozzle systems)

7 - Strainer and Filter


(In section 8.4, only the Residential – Section 44 - tests are being targeted)

8 – General Performance



9 – Water mist Nozzle Requirements



10 - Exposure Tests on Nozzles Incorporating Polymeric Gaskets


Tests to be carried out only as part of UL Listing (certification). Domestic environments at 1.4m is not considered an environment highly susceptible to corrosive atmospheres.

13 – Water Flow Test



15 – Water Droplet Size and Velocity


Positions are customised for the horizontally oriented, 65° vertical spray fan, so that nozzle changes can be shown to provide equivalent spray characteristics.

17 – Deflector/Orifice Assembly Test



25 – Corrosion Tests


Tests to be carried out only as part of UL Listing (certification). Domestic environments at 1.4m is not considered an environment highly susceptible to corrosive atmospheres.

31 – Heat Resistance


Tested under realistic fire conditions

32 – Vibration



33 – Rough Usage Test



34 – Impact Test



38 – Clogging Test



44 - Residential Area Fire Tests


Smartscan has been tested against the similar BS 8458, which is narrower in scope (does not currently include pre-engineered systems) and has more onerous fire performance tests (including forced ventilation and no doorway lintels) than UL 2167. These have been run in Exova Warringtonfire and passed successfully.

49 - Design and Installation Instructions



50 - Water Mist Nozzle Marking



Only third-party certification to a product standard is a true test of a product constancy and reliability, even under worst-case scenarios. This is because it scrutinizes the product performance and production in depth and over time. Also, since the declaration is made by the third party, it is less prone to bias.

Compliance with a standard, on the other hand, is merely a self-declaration by a manufacturer that a product meets the standard’s requirements based on one set of tests on one product at one moment in time. Clearly, this does not necessarily mean that the product will perform consistently or reliably in worst-case scenarios or in the long term. This is because the manufacturer may have limited their testing only to the ideal scenarios.

In the case of BS 8458:2015 the situation is even worse because it is a design and installation standard. Its requirements for component testing ignore environmental factors that can be found in the field and which can impact the long-term reliability of a product.

Declarations of compliance to BS 8458:2015 therefore only mean that the system has been designed and installed (and fire-tested in its optimum setting) to that standard. This is useful, but provides absolutely no assurance about a product’s reliability or real performance.

To bridge the assurance gap, product certification to standards like LPS 1283, UL 2167 or FM 5560 are also required.

If this subtlety was not confusing enough, building control officers, fire risk assessors and specifiers also have to remember that BS 8458:2015 only applies to certain kinds of water mist fire protection systems.

Take the Automist Smartscan. Although exhaustively and successfully third-party tested, in terms of performance to challenging worst-case scenarios, it cannot be certified against or said to comply with BS 8458. This is because it is an innovative alternative, which falls outside of the standard’s arbitrary, but design specific definition of what constitutes a conventional water mist system.

The only formally recognised vehicle for declaring its effectiveness, reliability and constancy in the UK is to undergo the LABC’s Assured process. This is a third-party witnessed/audited process where the LABC assigns a fire engineer to verify that the product and installation will work as intended. Automist Smartscan's credentials were further validated by BSi who have issued a Verification Certificate that also found the system to meet the performance requirements of BS 8458:2015.

For compliance in the USA and elsewhere in the world, the Smartscan will undergo the UL (Underwriter Laboratories) listing process to UL 2167. This process is thorough, well recognised and highly respected internationally.

In anticipation, Plumis based its testing for the LABC Assured process on UL 2167.