For open-air aboveground tanks the Turkish Fire Protection Regulation (BYKHY) has three sets of rules, all in Article 119: minimum distances to the surroundings and between tanks (Annex 12/C), the bund volume and construction that contain a spill, and a protection zone kept clear round the tank. This article gives Annex 12/C as read from the page image and works through the bund calculation with an example.
Which text is this based on? This article follows the consolidated text of the Turkish Fire Protection Regulation (BYKHY) as amended up to 09.07.2015 (Official Gazette no. 29411), read together with the BYKHY Guide issued by the Ministry of Environment, Urbanisation and Climate Change in December 2024. The regulation has been amended since 2015, and the Guide itself states that the legislation in force prevails where the two differ. On a real project, check the latest text published in the Official Gazette and confirm with the local authority or fire brigade.
Annex 12/C: minimum safety distances
Article 119(1) ties the distance of open-air aboveground tanks from inhabited areas, roads and railways to Annex 12/C, and Article 119(3)(a) uses the same table for the protection zone. Distances are the shortest distance from the tank's outer shell (consolidated text p. 71; Guide p. 264).
| Tank volume (litres) | Neighbouring boundary, main road or railway (m) | Site administration building (m) | Between tanks (m) |
|---|---|---|---|
| 1,000 or less | 1.5 | 1.5 | No value |
| 1,001 – 3,000 | 3.0 | 1.5 | 1 |
| 3,001 – 45,000 | 5.0 | 1.5 | 1 |
| 45,001 – 115,000 | 7.0 | 1.5 | 1.5 |
| 115,001 – 190,000 | 10.0 | 3.0 | One quarter of the sum of the diameters of adjacent tanks |
| 190,001 – 375,000 | 15.0 | 5.0 | |
| 375,001 – 1,900,000 | 25.0 | 7.5 | |
| 1,900,001 – 3,750,000 | 30.0 | 10.0 | |
| 3,750,001 – 7,550,000 | 40.0 | 15.0 | |
| 7,550,001 – 11,375,000 | 50.0 | 17.5 | |
| 11,375,001 or more | 55.0 | 20.0 |
The two notes under the table are requirements too: the tank site needs a bund system in which spills collect easily, and every tank connects to it through a channel system with suitable fall, separate from storm water, drainage and sewer systems.
Example: two adjacent tanks of 12 m and 8 m diameter, each larger than 190,000 litres, need (12 + 8) / 4 = 5 m between them. Two 50,000-litre tanks fall into the 45,001–115,000 row: 7 m to the site boundary, 1.5 m to the administration building and 1.5 m to each other.
A typesetting difference in the Guide. The table drawn in the Guide's Figure 119.1 (p. 195) prints some row limits as "45,000 – 115,000", "115,000 – 190,000", "3,750,001 – 7,750,000" and "7,750,000 – 11,375,000". The Guide's annex table (p. 264) and the 2015 consolidated text (p. 71) read 45,001, 115,001, 7,550,000 and 7,550,001. The table above follows the annex; for a tank close to a row limit, check the text in force.
Bund volume (Article 119(2))
| Case | Required bund volume | Clause |
|---|---|---|
| Tanks of equal size | The volume of one tank | 119(2)(a) |
| Tanks of different sizes | The volume of the largest tank | 119(2)(a) |
| Portable tanks | 75% of their total volume, or at least the largest portable tank | 119(2)(b) |
| Mixed storage (fixed + portable) | The sum of the volumes found under (a) and (b) | 119(2)(c) |
| Crude oil and carbon disulphide | The total volume | 119(2)(ç) |
The portable-tank rule states two conditions together; the safe reading is to take the larger. The Guide draws the calculation in Figure 119.2 with two equal tanks and one larger tank (p. 196).
Example: one bund holds three 50 m³ fixed tanks and portable tanks totalling 8 m³, the largest being 2 m³. The fixed tanks need 50 m³; the portable tanks need 8 × 0.75 = 6 m³ (more than the 2 m³ largest tank). The mixed case therefore needs 50 + 6 = 56 m³.
How many bunded areas?
- Class I, II and III liquids other than crude oil and carbon disulphide may share one bund while the total, expressed as Class IA, does not exceed 12,500 litres (119(2)(d)).
- For crude oil or carbon disulphide, one bund may serve up to 15,000 m³ stored and 700 m² of bund surface (119(2)(e)).
- Rules (a) and (b) also apply when classes are stored together (119(2)(f)).
Bund construction
- Excavated or walled; everything except the sealing liner non-combustible, and the walls tight during a fire. A combustible liner must be protected from fire (119(2)(g)).
- Tanks stand at least 3 m from bund walls lower than 4/5 of the tank height, measured from the shell (119(2)(ğ)).
- Pipes through walls are sealed; the bund can be drained of water; outlets are closable and fitted with a device that separates the flammable liquid (119(2)(h)).
- Internal dividing walls are at least 4/5 of the outer wall height; channels have an open top, which may take a grating (119(2)(ı)).
- Only fittings and pipes, besides the tanks, may be inside the bund (119(2)(i)).
Protection zone (Article 119(3))
- A protective distance per Annex 12/C is kept round the tanks (119(3)(a)).
- It is measured from the shell, and at least two thirds of it lie outside the bund, measured at the top of the inner edge of the bund wall (119(3)(c)).
- Where a wall or embankment outside the bund, of at least 120 minutes fire resistance and at least 4/5 of the tank height, provides the safety, the zone may be narrowed with the fire brigade's opinion (119(3)(ç)).
- Facilities and buildings needed to run the depot may stand in the protection zone if they are outside the bund (119(3)(d)).
For storage in portable containers, the zone width comes from Annex 12/D, measured from the outer boundary of the container group (119(3)(b)):
| Volume stored | Protection zone width |
|---|---|
| 10 – 30 m³ | 10 m |
| 30 – 100 m³ | 20 m |
| Above 200 m³ | 30 m |
Annex 12/D gives no value between 100 and 200 m³ or below 10 m³, in either text (consolidated text p. 72; Guide p. 265). Agree the value with the fire brigade; for 100–200 m³, taking the next row up is the safe side.
Hazard zones and site layout
Unless stated otherwise, 5 m from the shell up to 0.8 m above ground is Zone 2; with bunded storage the bund up to 0.8 m above its top edge is Zone 1 (119(4)(a) and (b)). The site is not open to general traffic and unauthorised entry is prohibited and signed (119(4)(c) and (ç)). See the hazard zones article.
Cooling water that keeps a neighbouring tank from heating up and igniting (Article 122(2)) and the regulation's approach to foam are covered in the Articles 98 and 122 article. For a large tank farm scenario see the port tank farm article.
Common mistakes
- Applying the LPG reduction notes to liquid tanks. The notes just above Annex 11 in the consolidated text, which cut distances by one third behind a 4-hour wall, belong to the bulk LPG tank table (Annex 10). Annex 12/C has no such ratio; narrowing is possible only through 119(3)(ç) with the fire brigade's opinion.
- Measuring from the tank centre. Annex 12/C distances are the shortest distance from the outer shell.
- Draining the bund into the storm water line. The table note requires a separate channel system; 119(2)(h) requires closable outlets and a liquid separator.
- Building the bund wall tight to the tank. Walls lower than 4/5 of the tank height must be at least 3 m away.
Frequently Asked Questions
What bund volume does BYKHY require?
Under Article 119(2): one tank's volume for equal tanks, the largest tank for unequal tanks; for portable tanks 75% of the total or at least the largest one; for crude oil and carbon disulphide the total volume.
How far apart must large aboveground tanks be?
Annex 12/C gives 1 to 1.5 m up to 115,000 litres and, for larger tanks, one quarter of the sum of the diameters of adjacent tanks, measured from the outer shell.
Is there a minimum distance between a tank and the bund wall?
Article 119(2)(ğ) requires tanks to stand at least 3 m from bund walls lower than 4/5 of the tank height, measured from the shell.
Can the protection zone be reduced?
Yes, with the fire brigade's opinion, where a wall or embankment outside the bund of at least 120 minutes fire resistance and at least 4/5 of the tank height provides the safety (Article 119(3)(ç)).
What distance applies to drums stored in the open?
Article 119(3)(b) uses Annex 12/D, measured from the outer boundary of the container group: 10 m for 10–30 m³, 20 m for 30–100 m³ and 30 m above 200 m³.
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Download MEP Calc on the App StoreRegulation on Fire Protection of Buildings (BYKHY), Official Gazette 19.12.2007/26735; consolidated text including the amendments of 09.09.2009/27344, 05.04.2012/28255 and 09.07.2015/29411: Article 119 (pp. 44–45), Annex 12/C (p. 71), Annex 12/D (p. 72); Annex 10 notes (p. 70). BYKHY Guide (Binaların Yangından Korunması Hakkında Yönetmelik Kılavuzu), Ministry of Environment, Urbanisation and Climate Change, December 2024: Article 119 and Figures 119.1–119.4 (pp. 194–198), Annex 12/C (p. 264), Annex 12/D (p. 265). Page numbers refer to the 72-page consolidated text and to the Guide's own page numbering. The binding text is the regulation in force as published in the Official Gazette.