Article 118 of the Turkish Fire Protection Regulation (BYKHY) covers two kinds of indoor liquid storage: a dedicated warehouse (Annex 12/A) and an isolated area inside the factory or workshop where the liquid is processed (Annex 12/B). The first is limited in litres per stack, the second in litres per square metre of floor. Construction, ventilation and floor requirements for both sit in the same article.
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.
Warehouse construction (Articles 118(1) and 118(5)–(9))
| Topic | Requirement | Clause |
|---|---|---|
| Fire resistance | Warehouse at least 120 minutes; doors at least 120 minutes | 118(1), 118(8) |
| Basement | No basement in a building storing Class I; no Class II in basements; at most 40,000 litres of IIIA and IIIB in a basement | 118(1) |
| Adjacency | Not adjoining dwellings or occupied rooms | 118(7) |
| Penetrations | Pipe penetrations and ceiling openings to adjacent rooms sealed with non-combustible material, vapour-tight | 118(6) |
| Floor | Impermeable and non-combustible; spills prevented from entering sumps, drains, pipes and service ducts | 118(8) |
| Ventilation | Adequate; if natural draught is insufficient, explosion-protected mechanical ventilation effective at floor level giving at least 6 air changes per hour | 118(9) |
| Lighting | In line with electrical and technical rules | 118(9) |
| Access | Unauthorised entry prohibited and signed | 118(5) |
Ventilation must be effective at floor level because the vapour collects low down. A fan with its intake at ceiling level may deliver 6 air changes per hour and still miss the point of the clause.
The stack rule and Annex 12/A (Article 118(2))
In one enclosed room, flammable liquid may be stored in at most 5 separate stacks, 3 m apart, with no stack exceeding the Annex 12/A value.
| Class | Original containers, total container volume (litres) | Portable tanks, total tank volume (litres) |
|---|---|---|
| IA | 2,500 | - |
| IB | 5,000 | 7,500 |
| IC | 10,000 | 5,000 |
| II | 30,000 | 40,000 |
| IIIA | 100,000 | 150,000 |
| IIIB | 200,000 | 300,000 |
The values are the same in the consolidated text (p. 71) and the Guide (p. 263). There is no portable-tank figure for IA. The IC portable-tank value (5,000 litres) is lower than the IB value (7,500 litres); both texts print it that way, so check this row against the text in force.
Mixed storage: IA equivalent
Where several classes share a room, the total is taken by the most hazardous class. The text gives the ratios as IA + IB/2, IA + IC/4, IA + II/12, IA + IIIA/40 and IA + IIIB/80, and the total expressed as Class IA may not exceed 12,500 litres. With several classes present, converting each to IA with its ratio and adding them up is the reading consistent with the wording "total in terms of Class IA".
| Liquid | Quantity (litres) | Ratio | IA equivalent (litres) |
|---|---|---|---|
| Class IA | 1,500 | 1 | 1,500 |
| Class IB | 6,000 | 1/2 | 3,000 |
| Class II | 24,000 | 1/12 | 2,000 |
| Class IIIB | 80,000 | 1/80 | 1,000 |
| Total | 7,500 ≤ 12,500 | ||
The IA equivalent stays below the limit here, but each stack must also respect its own Annex 12/A value: 6,000 litres of IB in original containers exceeds the 5,000-litre figure, so it is split across two stacks. Note that 12,500 litres is exactly 5 stacks of 2,500 litres of IA; the two rules dovetail. Show the calculation in the design report and get the fire brigade's acceptance.
Storage in factories and workshops: Annex 12/B (Article 118(3))
Storage inside a building where the liquid is processed is allowed on two conditions: the quantity stays within Annex 12/B, and the store is an area isolated from the process area.
| Maximum storage area (m²) | Permitted quantity (litres per m² floor) | Fire resistance (minutes) | Fire protection |
|---|---|---|---|
| 15 | 70 | 60 | No |
| 15 | 175 | 60 | Yes |
| 50 | 140 | 120 | No |
| 50 | 350 | 120 | Yes |
Per the footnotes, "fire protection" means a sprinkler system, carbon dioxide, dry chemical powder or another suitable system, and the combined Class IA and IB quantity may not exceed the Annex 12/A value (consolidated text p. 71; Guide p. 263).
Example: a 50 m² isolated store with 120-minute construction and a fixed system may hold 350 × 50 = 17,500 litres, with the IA and IB part separately capped by Annex 12/A. Without protection the limit would be 140 × 50 = 7,000 litres. Fixed protection raises the allowance by a factor of two and a half.
The regulation gives no design criteria for that system. If sprinklers or foam are chosen, the design follows the relevant standard; the approach is in the Articles 98 and 122 article, and EN 12845's flammable liquid annex in the Annex G article.
Hazard zones
The store room is Zone 1; a 5 m radius from its outside doors, windows and openings is Zone 2 up to 0.8 m above floor (118(4)). Lighting, sockets and fans in the store are therefore explosion-protected. See the hazard zones article. The Guide's Figure 118.1-2 (p. 193) shows the 3 m stack spacing and the 120-minute walls, doors and windows.
Common mistakes
- Reading Annex 12/A as a room total. It is per stack; the room is limited by 5 stacks and 12,500 litres IA equivalent.
- Not isolating workshop stock. Annex 12/B applies only to an area separated from the process.
- Using the protected rows without a system. 175 and 350 litres per m² need fixed fire protection.
- Connecting the floor gully to the sewer. Article 118(8) forbids spills reaching sumps and drains.
Frequently Asked Questions
What fire resistance does a liquid warehouse need under BYKHY?
At least 120 minutes under Article 118(1), with doors of at least 120 minutes under Article 118(8).
How many stacks are allowed in one store room?
Article 118(2) allows up to 5 separate stacks, 3 m apart, each within its Annex 12/A value, with the total expressed as Class IA not exceeding 12,500 litres.
Can flammable liquids be stored in a basement?
A building storing Class I may not have a basement and Class II may not be stored in basements. Classes IIIA and IIIB may be stored in a basement up to 40,000 litres (Article 118(1)).
How much liquid may be stored inside a factory?
Under Article 118(3) and Annex 12/B, in an area isolated from the process: up to 15 m² with 60-minute construction, 70 litres per m² (175 with fixed protection); up to 50 m² with 120-minute construction, 140 litres per m² (350 with fixed protection). IA plus IB may not exceed the Annex 12/A value.
Is there a ventilation rate for liquid stores?
Article 118(9) requires, where natural draught is insufficient, explosion-protected mechanical ventilation effective at floor level giving at least 6 air changes per hour.
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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 118 (pp. 43–44), Annex 12/A and Annex 12/B (p. 71). BYKHY Guide (Binaların Yangından Korunması Hakkında Yönetmelik Kılavuzu), Ministry of Environment, Urbanisation and Climate Change, December 2024: Article 118 and Figures 118.1-2 and 118.4 (pp. 192–194), Annex 12/A and 12/B (p. 263). 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.