If you have a question about Alsigns, Surelite, Permaglo or the hydrogen-light industry that isn't answered here, send it by e-mail to our contact address (or use our website enquiry form) and our President and C.E.O. Douglas Williams will endeavour to answer it for you.

FAQs updated: April 2009

1. FAQs about our website:

1.1 What is an F.A.Q. (or "faq")?
1.2 What are Alsigns, Surelite, Permaglo and Trasers?
1.3 Do your web-prices include VAT?
1.4 How quick is the delivery of goods bought online?

2. FAQs about Tritium signs:

2.1 What is Tritium gas?
2.2 How does a Tritium exit sign work?
2.3 Are self-luminous signs radioactive?
2.4 What happens if the sign breaks?
2.5 How are they disposed of?
2.6 From how far should one be able to see a fire exit safety sign [PERMAGLO]? and what guidance is there on the best spacing or positioning of signs?

3. Technical FAQs about the Tritium industry:

3.1 How is Tritium created?
3.2 Aren't hydrogen-atomic forms of illumination banned by the government and aren't its agencies against the use of this technology?
3.3 Are there any British Standards or Legislative Regulations governing "isotopic-hydrogen" light safety exit signs?
3.4 What relevance has the Radioactive Substances Exemption Order 1985 to manufacturers? And what under the Order are Relevant Articles, Classes A, B or C?
3.5 Can you tell me more about the ERA test house?
3.6 What is the status of BSRIA?
3.7 Which kinds of premises require a fire certificate?
3.8 Are PERMAGLO self-powered exit signs as good for Cinemas as they say?
3.9 I understand you were connected with the foundation of the Safety & Reliability Society Ltd? Is their methodology of risk assessment applicable to all industries and all services or is it just for engineers? [R.C., Maidenhead].
3.10 Hydrogen is plentiful and so readily available for use or exploitation. For instance, one can make hydrogen light with tritium gas [a hydrogen isotope] : further, tritium gas is a component in the H-bomb. How are these peaceful and military uses of hydrogen carried out?

1. FAQs about our website:

1.1 What is an F.A.Q. (or "faq")?

An FAQ is a list of Frequently Asked Questions that help to answer some common queries that people have raised. Return to Top

1.2 What are Alsigns, Surelite, Permaglo and Trasers?

Alsigns is the "short" group description for our holding company Alsigns (Best-Surelite) Self-Powered Limited. We manufacture and retail Surelite self-lit products and Permaglo exit and directional safety signs, and we import and distribute Swiss-made Traser watches to UK retailers. Traser® is the brand name for self-illuminated products (including watches) made by MB-Microtech. Return to Top

1.3 Do your online prices include V.A.T?

The answer here is yes! Our prices on the website are all inclusive of Value Added Tax (VAT). This means the price you see quoted is the price you pay. Return to Top

1.4 How quick is the delivery of goods bought online?

We post out purchased goods almost immediately, so that most items arrive at a UK purchaser's address within 24 hours. Goods purchased from abroad obviously take a little longer - usually about 4 or 5 days. Return to Top

2. FAQs about Tritium signs:

2.1 What is Tritium gas?

Tritium is one of the "clean" sources of energy. It is a "green" gas, a weak radiator around us all the time in the air. It is a product of the Sun (a natural atomic reactor) as well as sources such as for example the water coolant in Heavy Water (atomic) Reactors. So it is nothing new. Chemically, tritium is hydrogen. So nothing unmanageable in that, either.

There is no measurable radiation on the external surfaces of a PERMAGLO tritium, self-powered, illuminated, exit sign. The relevant British Standard for the manufacture of all EXIT, emergency, warning and advisory signs [BS 5499 : Part 2] states that if the provisions of that Standard are observed then the product is safe.

Tritium gas (or Hydrogen3) is controlled respecting the extent to which it can be incorporated in artefacts manufactured or researched within the Surelite division of Alsigns, by reference to the Defence Standard 62, which we also all follow in civilian applications. What is good enough for the British Tommy is good enough for us!!

All signs, etc., carry a directive [again in accordance with the Standard] that the sign, or other product, is to be returned to the manufacturer at the termination of its life, for safe disposal. Do not be worried by that aspect - it has been worried over by responsible and dedicated authorities [of which this company is one] for generations... just throw your mind back to the "Fleck Report" and the "Nirex" organisation, and, more recently, what we have written on the subject. Return to Top

2.2 How does a Tritium exit sign work?

Self-luminous signs use the electrons from tritium (also called hydrogen 3 gas or H3) to provide illumination without the need for a source of electrical power. The process is very similar to that in your television set picture tube whereby an electron is used to illuminate the front screen of the tube. The electrons from tritium however have only about one quarter of the energy of the electron in a colour TV picture tube. That is why self-luminous signs are not visible in daylight while TV pictures are. Actually, the tritium electron from the tritium has such a low energy that it cannot even penetrate an ordinary sheet of paper. Because of this very low energy level, tritium is one of the safest and most benign of all radioactive materials and is therefore approved by the relevant authorities for use in self-luminous signs in commercial buildings as well as all commercial aircraft.

To produce the illumination, the tritium gas is contained within a hermetically sealed glass tube. The inside surfaces of the tube are coated with a phosphor just like the inside surface of a television picture tube. Electrons emitted by the tritium bombard the phosphor, causing it to produce illumination. Return to Top

2.3 Are self-luminous signs radioactive?

Although tritium is a radioactive isotope, our products emit no radiation. The gas is hermetically sealed into glass tubes. The beta emissions from the tritium gas are completely contained within the tubes. There is absolutely no risk of radiation exposure from normal use of our product. Great care is taken in the construction of our signs to insure that they will stand up to extremely tough handling. Return to Top

2.4 What happens if the signs break?

Keep in mind that, for breakage to occur, the outer aluminium frame and inner protective plastic housing would also have to be destroyed. In this scenario, the released tritium gas would rise and dilute rapidly in the air. If however a person were somehow trapped in a 3m x 3m x 3m room with a sign in which all of the tubes had broken, that person's radiation exposure would be similar to that received from a dental X-ray. These signs would not be licensed for use if there were any chance that they posed a health risk to the public in a normal accident event. In fact, self-luminous signs have been used extensively throughout the world for more than 25 years without incident. Return to Top

2.5 How are they disposed of?

It is unlawful to abandon or dispose of self-luminous signs except by transfer to companies specifically licensed by the Environment Agency. They cannot be thrown away with the normal household rubbish. We will accept the return of any self-Luminous signs - call us for details on 01536 201525. Disposal is carried out in specialist facilities that are licensed to handle low-level radioactive waste. Return to Top

2.6 From how far should one be able to see a fire exit safety sign [PERMAGLO] and what guidance is there on the best spacing or positioning of signs?

The viewing distances of self-luminous fire exit safety signs are shown in millimetres [with their conversions alongside]. Note: the height [h] of a sign frame is [always] shown first, followed by the width [w]. The thickness, if relevant, would be [t].

Sign Size in mm Legible up to
100 x 100 4.5m (15 ft.)
200 x 150 7.7m (25 ft.)
400 x 300 15m (50 ft.)
600 x 450 23m (75 ft.)

Signs are positioned near to any first aid boxes/positions and positioned at any change of direction in, for example, the illuminated escape route. See Designing a Self-lit Emergency Escape Sign System for a fully illustrated explanation of sign positioning and regulations. Return to Top

3. Technical FAQs about the Tritium industry:

3.1 How is Tritium Created?

Universal Hydrogen Light

Momentous discoveries at the end of the twentieth century in the field of nuclear physics gave great opportunities for the development of various technologies for the practical application of atomic energy in the service of mankind. New scientific methods and technical equipment were developed which allowed the widespread application of nuclear energy for industries such as oil, scientific research, medicine, space technologies, aircraft, transport [trains] and agriculture, etc. As science advanced and fresh fields were explored - new ideas became regular practice. People lost their distaste for chemistry and their fear of radiation, through greater familiarity. They saw that the possibilities of nuclear energy are virtually unlimited and offer to mankind the promise of seizing new worlds.

In this answer, I want to acquaint experts as well as the general public with the knowledge that the technology exists [for use across any industry and any country or territory] and I want them to have information on the basic principle of producing light without electricity by implementing the capabilities of one of the most popular chemical elements in nature - hydrogen in the form of its isotope named tritium (1H3). Further, I will make during this discussion some remarks about safety and reliability in relation to hydrogen light technology. Finally, it is my intention to cover the International Commission on Radiological Protection’s (ICRP) standards and limits, respecting any contact with ionizing radiations. There is not any risk to the public from hydrogen light, e.g. from exit signs, especially those to the BS 5499 specification.

The method of producing light inside the glass tube filled with tritium gas is similar to the well-known technology of the cathode ray tube that is a main part of the TV screen. The internal surface of the screen is covered with phosphor, which produces bright light as a result of being bombarded with a beam of accelerated electrons. These electrons are created by thermo-electric emission released from the surface of the metal cathode heated to high temperatures. The whole TV screen process is based on using electricity - for heating the cathode - to create the electromagnetic field for the acceleration of the electrons to reach the internal surface for interacting with the phosphor. The main difference of tritium light sources from the electric/cathode ray tube in hydrogen technology, is that the glass tube filled with tritium gas does not need any electricity sources, mains or battery, to create light.

Tritium has the same physical structure as hydrogen (1H1) but it has a spare electron in the atom that makes it unstable. Tritium is a radioactive isotope with a half-life of 12.3 years. The nucleus contains one proton and two neutrons. As a result of nuclear reaction it releases electrons (beta-particles) having energy of 18.1 KeV (kilo electron volts) converting into a stable (non-radioactive) element helium-3 (2He3).

The glass tube, the internal surface of which is covered with phosphor, is evacuated, filled with the tritium gas [emitting photons] and hermetically [air-tight] sealed. It becomes a long-life source of light [twenty-five years]. The light photons emitted are created as a result of interaction of the electrons released from tritium with the phosphor atoms. For example, if the total radioactivity of the tritium in the tube is 1Ci (3.7x1010Bq), then 37 billion electrons will interact with the equivalent number of phosphor atoms during the period of one second, emitting the same number of photons. After the period of 12.3 years the quantity of photons will have halved, so 18.5 billion photons per second will be emitted.

There are no natural sources of tritium on Earth, although it exists in rainfall; so tritium has to be created artificially. There are three routes: lithium; a thermal neutron/deuterium reaction; or reclamation. The nuclear reactions are with slow thermal neutrons of 0.025 KeV (kilo electron volts) energy, supplied by power or research reactors preferably with a moderator of natural water (H2O) or heavy water (deuterium D2O). An alternative source is through a neutron generator or accelerator.

The first method is based on using a metal target of the isotope Lithium-6 (3Li6). It is exposed to a stream of thermal neutrons that lead to the following nuclear reaction:

(n, d): 3Li6+ 10n > 2He4 + 1H3 (tritium)

It produces helium (helium nucleus) and tritium. The effective cross section of absorptivity of the thermal neutron in the nucleus of lithium is 910 barns (1 barn = 10-24cm2). There are two lithium isotopes in nature: Lithium-7 (92.58%) and Lithium-6 (7.42%). Lithium-7 has a very small effective cross section of absorptivity of the thermal neutrons (some 0.003 barn), so the way to produce more tritium is to increase the content of Lithium-6 in the metal target. To avoid the creation of lithium hydroxide the target is placed in a vacuum or an area filled with a gas free of water vapour. Usually, the lithium target is placed into a metal cylinder made from zirconium that has a very small effective cross section for capturing neutrons. The cylinder is connected to a vacuum pump that gives the ability to re-pump its contents into another vessel. The metal cylinder with the lithium target has to be placed in a suitable place in the reactor where the stream of thermal neutrons has enough density. After a period of time, the pressure in the cylinder increases as a result of the released tritium and helium. This gas mixture needs to be re-pumped into a special container having depleted uranium. Transformation of the tritium from a gas to the solid condition is a process of absorption into the surface of the uranium as a uranium hydride (UH4) with a standard methodology of making hydride. This is also a way of separating the tritium from the helium. Tritium as a gas for filling the tubes can be released from the uranium hydride with heating procedures.

The other method for the production of tritium is based on the following reaction:

(n, ): 1H2(deuterium) + 0n > 1H3(tritium) +

The effective cross-section of absorptivity of the thermal neutron (0n1) from the nucleus of another heavy isotope of hydrogen, deuterium (1H2), is 0.57 barn. In thermal reactors, using heavy water D2O, deuterium, as a moderator, during the interaction of the nucleus of deuterium with a thermal neutron, tritium is produced and a gamma quantum is released.

Tritium is a strategic material and it was used initially only for military purposes in thermonuclear [hydrogen] weapons. Each warhead contains approximately 4g of tritium. Neutron bombs (that could release more radiation as a powerful stream of neutrons) contain 10-13g of tritium. Producing the light elements as tritium-filled tubes is a good way to convert this material from military uses to employment by the civil industry – from an element of a super-destructive nuclear weapon to a range of peaceful products: emergency exit signs, power-keyrings, power light cord pulls, house numbers, barbeque features and Christmas tree decorations.

Reclamation is occasioned by tumbling expired bare light sources in a rotating sealed drum such that they will be broken by a heavy billet which is tumbling with them thus releasing tritium and helium. The tritium is captured in hydride form for re-cycling and the helium is dispersed in accordance with regulatory provisions.

In Surelite and Alsigns operations, various automatic barriers are in place to avoid releases of gas, and working practices [local rules] observe the principles of safety and reliability. Explicitly defined “accident incidents” and “emergency response times” together with “safe endurance areas” and “escape routes” comprise an approach to the issues of reliability and tolerability. The relative arrangements are set out for “escape-ways” leading from the laboratory to an “assembly area/safe endurance area”, but also for facilities and opportunities for monitoring and controlling the “accident incident”, plus evacuation and mustering in the assembly area within the “emergency response times”. These can be calculated by computer simulation. By calculations employing a matrix, a “safe endurance area” is established to indicate what arrangement in an incident [defined by duration] is required and for how long, taking into account uncertainties. It can be seen that for “accident incidents”, “emergency response times” and the required “safe endurance area”, the assembly area arrangements do not need to be the same. They are justified by associated considerations such as endurance requirements and times. Incidents are, of course, classified as to their frequency and duration and a database is built up for the purpose of hazard identification and modeling.

BS 5499 limits the amount of gas in a single tube to less than 80Gbq and in any one product to less than 1Tbq. The International Commission on Radiological Protection (ICRP) sets standards for work with ionizing radiations and defines an Annual Limit of Intake (ALI) for tritiated water and Derived Air Concentrations (DAC) for tritium gas and tritiated water. The DAC represents concentration limits, which would give the ALI if personnel were exposed to them for a complete working year (2000 hours). The DAC values for tritium gas and tritiated water are respectively 2 x 1010Bq m-3 and 8 x 105 Bq m-3 and it is important to realize that these are average values for the year not levels which may never be exceeded.

Estimates are made in the laboratory of the maximum tritium concentrations resulting from a breakage. If, for example, the contents of one tube containing 80 Gbq of tritium are released into a small room of volume 40m3 with no ventilation, the resulting concentration will be 2 x 109m3 or ten times less than the DAC for tritium gas. If 2% of the tritium is assumed to be present as tritiated water (the maximum allowable) then its concentration would be 4 x 107Bqm3 or 50 times the DAC. A total of 40 hours exposure to this concentration would be required to give the permitted ALI (annual limit of intake).

As tritium is a radioactive source and in spite of the fact that its radioactive soft (beta) emission cannot penetrate either simple materials such as cotton or paper, or even the human skin, care must be taken. According to the British and International standards all products are to be tested and certified under the regulations issued. Tubes are made from borosilicate glass that is much stronger than standard glass. Drop and vibration tests are executed for each type of final product that uses tritium photo electronic lighted elements. The hazard arising from accidental release of tritium gas is negligible, even with poor ventilation; however, because a trace of tritium water might be present then in the event of a breakage, the staff should leave for ten minutes, or more where the endurance arrangement required is longer. In fact, the light units are extremely durable and only violent handling will damage them.

Such “safe exit” products are not considered as being radioactive as at the outside surfaces of the product there is not any radiation released during their working life, so the risk of an accident with them is far less than with the electricity and electric equipment used every day. Numerous advantages are claimed for the products compared with traditional electric light. They are self-powered [non-electric], mobile and require no cabling – no danger of a spark [which makes them so useful in hazardous areas]. No maintenance, no technical failures and they would fail safe. They are especially relevant in difficult terrain; for example: deserts, mountains, forests and also on off-shore rigs because they do not need power lines. Photo-electronic light is not going to replace the electric light, at least not in the near future (!) but it is going to furnish more illumination and comfort more people with new, unusual and safe products and safe solutions together with more toys and night lights for children; and in doing that it will save conventional electric generating capacity for other uses. Return to Top

3.2 Aren't hydrogen-atomic forms of illumination banned by the government and aren't its agencies against the use of this technology?

No! They cannot be, because anything which is in accordance with International and public law is allowable, especially when it contributes to safer living conditions, a safer environment and future survival of our civilisation.

Overarching all the government's provisions there is a higher authority: that of States which are party to the "Treaty on the Non-proliferation of Nuclear Weapons [1968 - 1970]". A Treaty is a formally concluded and ratified agreement between States - in this case between England, Russia and France, among others, for instance. France is extremely advanced in this field. This Treaty contains provisions which legitimise all the activities of Surelite Limited.

Under the Treaty quite important States affirm the principle that the benefits of peaceful applications of hydrogen-atomic technology, including any by-products should and must be available for peaceful purposes in any qualified State. Following from and further to that Surelite Limited may participate in the exchange of scientific information for development of the APPLICATIONS of the aforementioned technology for peaceful purposes if such furtherance is effected without force. Of course, Surelite Limited has always, in accordance with the Treaty, operated safeguards against diversions from legitimate uses - procedures likewise, but always without hampering the economics or technicalities of international co-operation and trade. Return to Top

3.3 Are there any British Standards or Legislative Regulations governing "isotopic-hydrogen" light safety exit signs?

There is an authoritative Standard produced under the auspices of the British Standards Institute [in particular, eminent members from prestigious departments, bodies and branches of State and giants of industry] committee FSB/1: that Standard is referenced - B.S. 5499 : Part 2 : 1986. It is particularly exhaustive in its criteria and its tests of performance. Alsigns [Best-Surelite] Self-Powered Ltd was the first company, world-wide, to pass this Standard with an independent test to the set provisions by the ERA test house (ERA Technology Ltd) of Leatherhead, England. The writer cut his teeth on the "hot wire test" which is specified as part of the materials' performance provisions.

The legislative provisions extend from the all-embracing Health and Safety at Work Act 1974 to the more recent Safety Signs and Signals Regulations 1996. Safety law is effected via the EC's requirements, but these have been tardily applied in Great Britain. For example, the Safety Signs and Signals Regulations 1996 was the implementation of ESSD (92/58/EEC) - only four years for the minister to start saving lives by signing the instrument - not bad. Return to Top

3.4 What relevance has the Radioactive Substances Exemption Order 1985 to manufacturers? And what under the Order are Relevant Articles, Classes A, B or C?

The Radioactive Substances (Gaseous Tritium Light Devices) Exemption Order 1985 followed on from the Radioactive Substances Act 1960 and consists of six [6] articles [the body of the Order also defines Classes A, B and C as Relevant Articles].

  • Article 1: names the order as above, its commencement [17.9.85], its application to "Relevant Articles" and its relation to government departments and waste.
  • Article 2: mentions certain applicable conditions under Section 1 of the Radioactive Substances Act 1960, and says who must register.
  • Article 3: details the conditions referred to in Article 2.
  • Article 4: defines exclusion of waste sources (ex Articles A, B and C) from the provisions of Section 6 (1) of the RSA 1960 - see also Section 30 of the Control of Pollution Act 1974 (a).
  • Article 5: deals with the exclusion of certain waste sources from Section 6(3) of the RSA 1960.
  • Article 6: excludes radioactive waste from Section 7(1) of the RSA 1960.

The following paragraphs summarise Articles 2 [required to register] and 3 [conditions relative to that].

Article 2

All persons must register under the Radioactive Substances Act, 1960, if they are manufacturers of Relevant Articles [Class A, B or C] or they store for sale or hire such Articles with activity exceeding 20 gigabecquerels [0.54 Curies, 540mCi];

Article 3

The main exemptions are:

(a) Tritium Oxide (and other water-soluble compounds of tritium) activity does not exceed 2% of total activity in a container or 100 MBq (2.7mCi) in a container of not more than 5 GBq (135 mCi).
(b) All Class A aggregate terabecquerels of activity do not exceed 5 TBq (135 Ci)
(c) All Class B on premises (except re railway vehicles) does not exceed 30 TBq (810 Ci).
(d) Class B not installed or in a railway vehicle is securely affixed or if stored, not for more than 1 month.
(e) Refers to railway vehicle light
(f) Railway vehicle
(g) Class C Article not stored for more than one month

There are various other provisions not of general application.

Exit signs are Class B artefacts.

Glow safety rings and polycarbonate-protected "Night Lights for Nervous Children" are Class A items. Return to Top

3.5 Can you tell me more about the ERA test house?

In the UK, testing and the independent certification of results of research and product performance are carried out by experienced teams organised within separate groups or divisions of independent test establishments. Some establishments such as RAPRA are associated in people's minds with rubber, while the Mining Institute in Derbyshire is associated, likewise, with mines; others such as BEEB with electricity.

ERA Technology Limited, of Cleeve Road, Leatherhead, Surrey, England, has within it the Explosion and Fire Hazards Group and the Industrial Products Department which, respectively, check and approve the individual test engineer's reports before issue and they did so in the case of Surelite Ltd (our company within the group of Alsigns [Best-Surelite] Self-Powered Ltd).

ERA is known world-wide for research, development and testing for industry. It is now part of the ITS laboratory in the USA. Return to Top

3.6 What is the status of BSRIA?

A good deal is said by giving the name of the organisation in full: the Building Services Research and Information Association, of Bracknell/Crowthorne, Berkshire, and by adding that BSRIA was strongly supported by DETR (the Department of Environment, Transport and the Regions] - nowadays DEFRA (the Dept. of Environment, Food and Rural Affairs), whose support continues.

One of the main aims of the Association is to spread news of new and better ways of doing things [e.g. regarding self luminous (no maintenance), twenty year life, safety exit signs are cheaper than electric signs]. Within the scope of the organisation's activities comes the work of steering groups which focus on projects worthy of examination by representatives from industry and in respect of which independent data sheets are drawn up by these groups demonstrating the advantages of new and innovative products compared with traditional solutions.

The results are verified in site investigations by BSRIA staff - in this case, for our group holding company [Alsigns], by Mr. Marcus Dicks, B.Sc.(Hons). Return to Top

3.7 Which kinds of premises require a fire certificate?

Every premises presents a fire hazard which needs to be addressed. For each premises the criticality and the priority given to its prevention depend on:

(a) the construction and layout of the building

(b) the nature of its occupancy [i.e. how many people work/live/sleep in it]

(c) its purpose, and

(d) the amount of flammable or explosive materials stored or used there [the fire load].

Premises requiring a fire certificate (issued by the Fire Authority for their district) have to comply with certain conditions in order to stay operational. The basic elements of fire safety, of which all employees need to take account, whether they have to apply for a fire certificate or not, are as follows:

1. The means of detecting fire and raising the alarm.

2. The means of fighting fire [extinguishers or fire blankets]

3. Adequate means of escape, including emergency lighting, where necessary, THE EARLIER THE BETTER.

4. Provision of suitable information [to the Fire Brigade, as well] and fire training.

Note: all fire extinguishers are now red, with a further band of colour to denote the type. Return to Top

3.8 Are PERMAGLO self-powered exit signs as good for Cinemas as they say?

The well-tried and trusted methodology of PERMAGLO exit and direction signs - that of self-luminescence, a maintained lighting system [cold source] where the illumination is continuous day in and day out, for twenty [20] years, without the need for repair or maintenance (apart from surface dusting of the sign unit), or any cabling, making it freely mobile is ideal for Cinemas. The technology embraces other forms of product, such as first aid, fire appliance and equipment point markers.

The relevant British Standards which they satisfy are B.S. 5499: Part 2 : 1986 [Specification for self-luminous fire safety signs] and the "British Standard Code of Practice CP 1007 : 1955 [Maintained Lighting for Cinemas] see below - both of which have stood the test of time.

The main point to emphasise is that this type of sign is [as indicated in the foreword to the Standard 5499], independent of any external source of energy and accepted for use in buildings where it is necessary or desirable that indicating signs be illuminated, e.g. bingo halls, ballrooms, clubs and other places of public entertainment.

These cinema signs are generally in accordance with the principles and criteria contained in the Nuclear Energy Agency document for Radiation Protection Standards published in three languages by the Organisation for Economic Co-operation and Development.

CP 1007 : 1955 (Cinemas), quoted above, was prepared by a joint committee of "The Institution of Electrical Engineers" and "The British Standards Institution - BSI". It includes a number of helpful observations:

Clause 334(c) lays down that light from signs should not be regarded as part of the essential illumination from the management lighting. Further, bright lights within the view of spectators facing the screen are not desirable. PERMAGLO's will still be lit and fulfilling their function when other systems [traditional] have failed.

Clause 322 states that any member of the audience should be able to see the way to the nearest gangway after a visual adaptation period of ten [10] seconds. The route of escape to the exit door should be clearly visible. The level of illumination quoted is 0.001 to 0.0025 lm/sq.ft.

Clause 324 provides:
(a) Safety lighting should be from sources installed solely for that purpose. (b) Bright sources of light or areas of high brightness are to be avoided, because they can dazzle. (c) Down-lights should be deep conical (or similar) fittings, recessed in the ceiling.

Clause 341(a) points out that the audience in the auditorium is already visually adapted to a low illumination level and all in the audience are moving in the same direction. A much lower illumination level, therefore, is acceptable for passages and stairways. The avoidance of glare and misleading shadows is especially important. Safety illumination should not be so high as to demand too rapid a visual adaptation from a person leaving the auditorium.

These authorities support the contention that PERMAGLO self-luminous signs are IDEAL for CINEMAS, clubs, etc. Return to Top

3.9 I understand you were connected with the foundation of the Safety & Reliability Society Ltd? Is their methodology of risk assessment applicable to all industries and all services or is it just for engineers? [R.C., Maidenhead].

Reliability and Risk Assessment methods came to me and eventually my Group when I as one of the founding fellows formed, as part of SARS (Safety & Reliability Society) Ltd and got Alf Keller as co-signatory to the application to the Registrar of Companies, Cardiff. At that time, also, I visited Sefton, Liverpool Council and personally got the agreement of the Town Clerk to our having Southport Town Hall Chamber for our Council meetings under Prof. Eric Green, who was the Society's first President, followed in that office by George Hensley who offered to teach me Reliability Mathematics. For the first four or five years of the Society I was SARS Treasurer and Council member.

The better methods of reliability of automatic systems [noting fractional dead time - FDT - together with demand probability] and safer operation of hazardous plants and the understanding of the techniques tuned in well with lecturing I did and with my position as the sole hydrogen facility [process plant] operator and manufacturer in the UK of atomic light sources and their use, for example, in dangerous atmospheres instead of hazardous technologies such as Swan/Edison's electricity. Risk Assessment is obligatory under the Ionising Radiations Regulations 1999 [Part II] to which I work.

Records are kept as the basis for expressing reliability in quantitive terms and in establishing failure rates for example in Boeing aircraft usages, a company for which many of our exports are destined and its relevance in fatal accident risk. That trend has developed into quality assurance [formerly BS 5750] and simplification of design. Alongside reliability and availability ranges maintainability [an Eric Green obsession], and interest is directed toward fault tree analysis [FTA] and human factors.

As part of my modus operandi a reliability assessment is carried out at every level of execution of a job, project or exploitation of the capabilities of the systems, apparatus or rigs operating here. It is during the pre-design stage, that the system boundaries are set and the parameters for reliability, maintainability and availability are determined. A broad judgement at the design-concept stage will predict the dependability of the plant and rigs, ventilation stacks, etc., to predict characteristics and identification of critical areas from the point of view of reliability. Later, more detailed work is performed to secure robust rigs, flexible design which can also facilitate maintenance, as well as resultant specifications including quality. The formal programme is managed by the Head of Reliability, in accordance with the defined objectives.

The outline definition pre-dates the concept design plan and caters for any trades off between constraints and that involves the reliability engineer.

Formal, documented procedures regarding reviews and the setting of design rules relating to components and tolerances are adopted to ensure the application of good engineering practice and that data is collected and the plan adhered to... and is continued during the operational phase and fed back in contribution to the safety study.

The background to the exercise is the question: "How safe is safe enough?" Risk is the frequency of the occurrence of the event multiplied by the magnitude of the consequences, and evaluations arising involve probabilistic methods. The risks I consider are: Occupational (workforce) risks; Community risks (neighbours and the environment); Economic risks (penalties from loss of assets, production and penalties). A target probability is derived for specific hazards in each case. In this connection one considers insurance covers held.

The probability of occurrence or the consequences must be reduced to bring the risks into an acceptable region. At the low end the risks are negligible and thus acceptable. In the intermediate region the risks are required to be reduced to "As Low As Reasonably Practicable (ASLARP). This may involve reducing the stored quantities of hazardous chemicals, fewer bottles of gas or introducing additional protective systems to reduce the probability of an incident.

Quantitative Risk Assessment is the means by which I determine the category of hazard. Quantitative risk assessment (QRA) involves: (a) the potential safety hazards; (b) estimation of the consequences; (c) probability of occurrence; (d) comparison against the acceptability criteria, which are identified using checklists and company records. Sometimes, preliminary hazard analysis (PHA) is used to uncover major hazards in operations or else hazard operability (HAZOPS) - both onshore and off-shore safety studies employing ''guide words'' to expose deviations from the design intention. The consequences are examined and computer simulations employed in the search for release scenarios. Any tendency of circumstances toward a major incident prompts the use of fault trees (FTA), top down, or failure mode and effects analyses (FMEA), bottom up, or "what if", approach by (a) splitting equipment into its component parts (b) examining each block for its modes of failure (c) classifying failure according to its effect (d) applying stressed failure rate for quantification.

In my opinion, having this technique recommends one to potential sponsors and clients; the methodology is for all industries and for all services in business. It is intimately concerned with risk, the same risk as is encountered in considering insurance cover but the solution is not merely to pay out premium money for restitution, one can find the weaknesses, put them right and save more.

F. Douglas Williams, President,
Alsigns/Surelite [Best-Lighting] Self Powered Group.
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3.10 Hydrogen is plentiful and so readily available for use or exploitation. For instance, one can make hydrogen light with tritium gas (a hydrogen isotope). Further, tritium gas is a component in the H-bomb. How are these peaceful and military uses of hydrogen carried out?

British industry thinks it has got something. Here is a cold source of light [one could say harmless] capable of a wide series of uses in all kinds of safety situations in any industry and any climate or country world-wide, unlike say the Swan-Edison [electric] method which is so devastatingly dangerous, naturally or harnessed, or the chemical industry where the danger is not confined by the boundary fence. British industry is right to think that between these things it has got something, self-luminous light above all.

A nuclear bomb [atomic (plutonium), hydrogen, thermonuclear] is developed according to whether the weapon is fission or fusion. The first plutonium bombs were pushed through a hole cut in the bottom of a bomber and devastated Hiroshima and Nagasaki in the last century [obliterating men, women and children]. This type of weapon was detonated with packed high explosive [TNT] as a trigger to ignite and split the plutonium, thus releasing massive fission energy.

The hydrogen bomb [H-bomb] works in stages. The initial part is similar to the plutonium bomb described above where the plutonium is split in a fission process which irradiates and heats the core to millions of degrees Celsius and starts the second part - a fusion reaction which develops into a main bombardment involving deuterium [heavy water], tritium [both hydrogen isotopes] and collisions with lithium deuteride in the centre of the activity. When this hydrogen-rich mix is super-heated [reaching 100 million degrees], the deuterium [2H] and tritium [3H] fuse, releasing immense amounts of energy. The final part occurs with a spectacular burst of neutrons which at these energy levels can split or fission U238 [depleted uranium]. This stage more than doubles the destructive, explosive power of the phenomenon and produces the greater part of the "fallout" which devastates whole regions, destroys human life and, using various delivery systems, wins wars.

Fission bombs can achieve intensive fire balls equivalent to the power of thousands of tons of TNT [kilotons]. H-bombs have no limit: "power without light" [megatons]. They are thousands of times more destructive than a fission bomb.

F. Douglas Williams, President,
Alsigns-Surelite Group.
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If you have a question about Alsigns, Surelite, Permaglo or the hydrogen-light industry that isn't answered here, send it by e-mail to our contact address (or use our website enquiry form) and our President and C.E.O. Douglas Williams will endeavour to answer it for you.