OISD Standards for Petroleum Depots and Terminals: A Practical Guide

Petroleum depots and terminals sit at the sharpest end of hydrocarbon risk. You are storing, transferring, and distributing Class A and Class B petroleum products at scale, under pressure, often in proximity to dense infrastructure. One gap in your safety framework is not an audit finding. It is a liability. OISD standards for petroleum depots and terminals exist precisely to close those gaps, and understanding them operationally not just on paper is what separates a compliant facility from a safe one.

This guide walks through the applicable standards, what they actually require, how audits work, and what the most common compliance failures look like on the ground.

Disclaimer: OISD standards define minimum requirements. Statutory legislation including the Petroleum Rules 2002 and the Petroleum Act 1934 must be followed concurrently. Where a conflict exists between OISD standards and statutory law, the more stringent requirement applies.

What Are OISD Standards and Why Do Petroleum Terminals Need Them?

OISD the Oil Industry Safety Directorate operates under India’s Ministry of Petroleum and Natural Gas (MoPNG) and publishes mandatory safety standards for the design, operation, and inspection of petroleum facilities. For depots and terminals, OISD standards define everything from tank spacing and dyke design to fire systems and emergency response, forming the legal backbone of facility safety compliance in India.

OISD was established in 1986 following a series of high-consequence incidents across India’s oil sector. It does not merely recommend best practices; its standards carry regulatory weight and are enforced through structured audit cycles. Non-compliance can trigger operational shutdowns, license cancellations under PESO, and significant legal exposure for facility operators and their leadership.

For terminal engineers and HSE managers, the key distinction to internalize is this: OISD standards are not design guidelines. They are minimum mandatory requirements. Meeting them is the floor, not the ceiling.

Core OISD Standards Applicable to Petroleum Depots and Terminals

The primary OISD standards governing petroleum depots and terminals span fire protection, layout, storage design, operations, and inspection. OISD-STD-117, OISD-STD-118, OISD-STD-244, OISD-STD-135, and OISD-RP-110 form the technical core, while OISD-STD-105, OISD-STD-129/130, and OISD-GDN-227 govern safe operations, asset integrity, and emergency preparedness.

Operators often make the mistake of treating OISD-117 as the only relevant document and ignoring how other standards intersect with terminal operations. That approach may get you through a surface-level audit and fail you on a detailed inspection.

Standard	Title / Scope	Primary Application at Depot Level
OISD-STD-117	Fire Protection for Petroleum Depots & Terminals	Fire water systems, foam systems, detection
OISD-STD-118	Layouts for Oil & Gas Installations	Tank spacing, boundary separation, gantry placement
OISD-STD-244	Storage & Handling of Petroleum Products	Comprehensive design, operation, and maintenance requirements
OISD-STD-135	Loading / Unloading Hoses	Inspection and testing standards for transfer hoses
OISD-RP-110	Static Electricity Control	Earthing, bonding, and static dissipation during product handling
OISD-STD-105	Work Permit System	Hot work, cold work, confined space entry controls
OISD-STD-129/130	Inspection of Tanks & Piping	Asset integrity, inspection intervals, defect acceptance criteria
OISD-GDN-227	Emergency Response & Disaster Management	ERDMP preparation and maintenance

OISD-STD-117: Fire Protection

OISD-STD-117 is the primary fire protection standard for POL depots and petroleum terminals. It covers the design, installation, and maintenance of fire water networks, foam systems, and fire detection across the entire facility. Every Class A and Class B product storage area falls within its scope.

The standard is not a standalone; it works in conjunction with OISD-STD-118 for layout-driven fire risk separation and OISD-STD-244 for tank-level fire protection provisions.

OISD-STD-118: Layouts

OISD-STD-118 specifies minimum separation distances between tanks, between tanks and pumps, between tanks and loading gantries, and between the facility and its boundary walls. It reinforces the layout intent embedded in OISD-117 and provides the geometric basis for consequence-informed facility planning.

Where OISD-117 tells you what fire protection equipment to install, OISD-118 determines the spatial envelope within which that equipment must function.

OISD-STD-244: Storage and Handling of Petroleum Products

OISD-STD-244 is arguably the most comprehensive single standard applicable to depot operations. It addresses the full lifecycle of petroleum storage from tank design and civil foundations through to day-to-day operating procedures, inspection regimes, and maintenance requirements. Facilities that structure their safety management system around OISD-244 as the master reference, with 117 and 118 as supporting documents, tend to have the most coherent compliance architecture.

OISD-STD-135: Loading and Unloading Hoses

OISD-STD-135 defines inspection, testing, and replacement criteria for flexible hoses used in loading and unloading operations. Hose failure during product transfer is a credible ignition source scenario. This standard is frequently under-resourced at depot level hose inspection records are among the first documentation gaps to surface during OISD audits.

OISD-RP-110: Static Electricity Control

OISD-RP-110 provides recommended practices for controlling static electricity during petroleum product handling earthing and bonding requirements for tank trucks, rail wagons, and loading arms; resistance testing frequencies; and approved materials for bonding cables. At loading gantries handling high-volatility Class A products, static control is not a peripheral concern. It is a primary ignition prevention measure.

Supporting Operational Standards

• OISD-STD-105 Governs the work permit system for hot work, cold work, and confined space entry. Mandatory at all petroleum handling facilities; non-implementation is a Major Non-Conformance during audits.
• OISD-STD-129 & 130 Set inspection intervals, methodology, and defect acceptance criteria for above-ground storage tanks and piping systems respectively. These feed directly into your asset integrity programme.
• OISD-GDN-227 Requires every petroleum depot to maintain a current, tested Emergency Response and Disaster Management Plan (ERDMP), updated to reflect current facility configuration, product inventory, and emergency contacts.

OISD-117 Compliance Checklist: What Your Depot Must Get Right

OISD-117 compliance for a petroleum depot requires verified conformance across tank farm layout, dyke wall containment, fire water demand calculations, ESD system functionality, electrical area classification, and emergency response documentation. A tank farm safety inspection checklist built against OISD-117 clauses should cover civil, mechanical, electrical, instrumentation, and operational dimensions simultaneously.

Walk any OISD audit team through a depot that has ticked boxes without understanding the engineering rationale behind each clause, and the gaps surface quickly.

Tank Farm Layout and Separation Distances

OISD-STD-117 and OISD-STD-118 together prescribe minimum separation distances between tanks, between tanks and facility boundaries, and between tanks and process or utility areas. These distances are not arbitrary; they are derived from consequence modelling for pool fire radiation and BLEVE scenarios.

Key layout requirements include:

• Inter-tank spacing: Minimum one-sixth of the sum of adjacent tank diameters for fixed roof tanks, with increases specified for floating roof tanks
• Tank to boundary wall: Minimum 30–45 metres for Class A products, varying by tank capacity
• Tank to pump house / loading gantry: Minimum 15 metres for Class A petroleum products
• Product pump manifolds: Per OISD-STD-118, these must be located outside dyke areas, preferably alongside access roads not within the bunded zone
• Loading/unloading gantry: Must be located at a safe, code-defined distance from storage tanks, with adequate vehicle manoeuvring space

In our experience reviewing depot layouts, the most common spacing violation is not in the main tank farm, it is in the secondary product handling areas and the loading gantry zone, where incremental infrastructure additions over years slowly erode the original separation intent.

Buffer zones per OISD-STD-118 also require maintained green belts between the facility boundary and adjacent residential or industrial land uses. These are not landscaping features, they are safety buffers, and their integrity must be preserved.

Dyke Wall Design Requirements

Every petroleum storage tank must sit within a dyke enclosure. Key requirements under OISD-STD-244 and OISD-STD-117:

• Containment capacity: 110% of the gross capacity of the largest tank within the dyke a hard, non-negotiable minimum
• Freeboard: Minimum 200mm below the top of the dyke wall
• Wall construction: Earthen or concrete; earthen walls require an impermeable clay core or lining
• Underground tanks: Where fill points are involved, a 30 cm high curb wall is required around the fill point area to prevent accidental overflow from reaching drainage or ignition sources
• Dyke drainage: Lockable drain valves, kept normally closed one of the most frequently violated requirements during audits

A dyke that drains freely into a common sump defeats the entire containment purpose. We have seen facilities with technically compliant dyke dimensions but permanently open drain valves a condition that fails the intent of the standard entirely.

Vent Requirements for Storage Tanks

This is a detail that OISD-STD-244 specifies precisely and that operators frequently get wrong on older tank farms:

• Tank vents must be located at least 15 metres from any ignition source or hazard
• Vents must extend at least 4 metres above ground level
• All vents must be covered with wire gauze to prevent ingress of debris, insects, or external ignition
• Ethanol tanks (increasingly relevant given India’s ethanol blending programme) require vents fitted with silica gel traps to prevent moisture ingress, which can cause phase separation and product quality degradation

Fire Protection Systems

OISD-STD-117 mandates a layered fire protection system:

• Fire water network: Closed-loop ring main design, laid above ground, with hydrants and monitors spaced at intervals not exceeding 30 metres. Minimum design pressure of 7 kg/cm² at the hydraulically most remote point.
• Foam systems: Fixed foam pourers on Class A and B product tanks above defined capacity thresholds; semi-fixed systems for smaller tanks. Foam compounds must be stored in appropriate conditions temperature-controlled, with shelf life actively managed.
• Water storage: Minimum 4 hours of fire water reserve at full pump design capacity. Storage must be in two interconnected, equal-sized compartments to allow maintenance of one tank without compromising reserve capacity.
• Fire pumps: Main pumps plus mandatory standby pumps. Standby units must be capable of auto-start, driven by diesel engines or with an independent power supply that is not shared with the main electrical supply. Pump performance must be re-verified after any repair; this is a documented audit check item.

Firewater demand calculations must account for simultaneous cooling of tanks adjacent to a fire scenario, not just the burning tank. Under-sizing the fire water reserve is among the most common findings at older depots.

Emergency Shutdown and Instrumentation

Emergency Shutdown (ESD) systems must be designed to meet the Safety Integrity Level (SIL) ↗ requirements derived from your HAZOP and SIL assessment. OISD-STD-117 requires:

• High-high level shutdown on all Class A storage tanks
• ESD activation at loading gantries both manual pull stations and automatic process triggers
• Fire and gas detection with alarm and auto-isolation capability
• Instrumentation maintenance records traceable and available during audit review

OISD does not prescribe SIL levels directly; that determination comes from your HAZOP and SIL assessment process. But it expects the output of that process to be implemented, tested, and verifiable.

Hazard Analysis Requirements Under OISD for Petroleum Terminals

OISD requires petroleum terminals above defined capacity thresholds to conduct formal hazard studies including HAZOP and, for major hazard installations, a Quantitative Risk Assessment (QRA). These studies must be completed before commissioning and reviewed every five years or following significant modifications. Findings must be documented, tracked, and closed out with evidence available during audits.

This is where many operators stumble. The HAZOP gets done during the project phase, findings get logged, and then action tracking disappears into a project closeout folder never to surface again. OISD auditors increasingly look for evidence of HAZOP finding closure not just the study report itself.

When Is a HAZOP Mandatory?

A formal HAZOP study ↗ is mandatory under OISD for:

• All new petroleum terminal projects before commissioning
• Existing terminals undergoing modifications that affect process safety barriers
• Facilities that have not conducted a HAZOP within the last five years

The study must be conducted by a multi-disciplinary team led by a qualified HAZOP facilitator, and the report including all action items and their closure status must be available as part of the facility’s safety documentation dossier.

QRA: Quantitative Risk Assessment for High-Consequence Terminals ↗

A QRA for petroleum storage facilities is required when the installation qualifies as a Major Accident Hazard (MAH) installation. QRA at a petroleum terminal typically covers:

• Individual Risk (IR) contours relative to the facility boundary and surrounding land use
• Societal Risk (SR) F-N curves benchmarked against ALARP tolerability criteria
• Consequence modelling for pool fires, jet fires, flash fires, and vapour cloud explosions

The QRA output directly informs your ESD system design, emergency response planning, and land-use planning submissions. It is not a standalone compliance document; it feeds every other layer of your safety case.

Regulatory Ecosystem: Where OISD Fits Among PESO, DGMS, and MoPNG

OISD operates under MoPNG and sets technical safety standards for petroleum facilities. PESO issues licenses for petroleum storage under the Petroleum Act 1934. These agencies are distinct but their requirements overlap at depot level compliance with one does not automatically satisfy the others. Where OISD standards and statutory regulations conflict, the more stringent requirement always governs.

Regulator	Governing Act	Primary Jurisdiction at Depot Level
OISD / MoPNG	Petroleum Act / MoPNG Orders	Technical safety standards, audit
PESO	Petroleum Act 1934, Petroleum Rules 2002	Storage licensing, quantity limits
DGMS	Mines Act 1952	Petroleum handling in mining contexts
CPCB / SPCB	Environment Protection Act	Effluent, air emissions, spill containment
Local Fire Authority	State Fire Services Acts	NOC for construction and operations

Key Updates and Trends: OISD in 2025 – 2026

OISD’s 2024 – 2025 revision cycle has introduced consolidated equipment standards, updated fire-fighting requirements for tank farms, and heightened emphasis on ethanol-blended fuel handling. Operators managing facilities designed to earlier editions of OISD-117 and OISD-244 should conduct a targeted gap assessment against the current published versions.

This is not a static regulatory environment. Several changes are directly affecting depot and terminal operators right now.

Consolidated Rotary Equipment Standards OISD has merged four separate rotary equipment standards STD-120, STD-121, STD-123, and STD-127 into the new consolidated OISD-STD-240. Facilities that reference the legacy individual standards in their maintenance procedures need to update their documentation to the merged standard.

Ethanol Blending Programme AR-AFFF Requirements India’s accelerating ethanol blending programme (EBP) has created a direct impact on depot fire protection design. Standard AFFF foam compounds are ineffective on ethanol-blended petrol fires; polar solvents break down the foam blanket rapidly. OISD now places increased emphasis on Alcohol Resistant AFFF (AR-AFFF) foam systems for any depot handling ethanol-blended petrol (E10, E20, and above). If your foam compound and proportioning system was specified for straight petroleum products, your fire protection system may no longer be fit for purpose for your current product slate.

Updated Fire Water and Foam Application Requirements The 2024–2025 revision cycle has updated foam application rates and introduced requirements for high-volume monitors in larger tank farm configurations. Facilities with fire protection systems designed to earlier editions should verify their hydraulic calculations remain compliant under the current standard particularly if tank sizes or product types have changed since the original design.

Practical Implication Any depot that has not reviewed its safety documentation against the current (2024–2025) versions of OISD-117, OISD-244, and the new OISD-STD-240 is carrying an unquantified compliance gap. Version currency is now an audit check item.

Conclusion

OISD standards for petroleum depots and terminals represent India’s most comprehensive framework for managing hydrocarbon storage risk at scale. OISD-STD-117 anchors fire protection requirements, OISD-STD-244 governs storage and handling operations, and OISD-STD-118 defines the spatial safety envelope within which everything else must function. The 2024–2025 revision cycle has added further layers AR-AFFF requirements for ethanol blending, consolidated rotary equipment standards, and updated foam application rates that operators running older facilities cannot afford to ignore.

The facilities that handle OISD compliance well are not the ones that sprint before every audit. They are the ones that have built the standard’s requirements into daily inspection routines, their MOC process, their HAZOP schedules, and their training programmes.

If your depot is approaching an audit cycle, undergoing expansion, or has not been assessed against the current versions of OISD-117, OISD-244, and OISD-STD-240, now is the right time to address it before an audit team does it for you.

For HAZOP studies, QRA, fire protection engineering, and end-to-end OISD compliance support for petroleum terminals,