Mobile lab at a petrol pump: what it tests and what follows

Short answer

Under Marketing Discipline Guidelines 2024 (MDG 2024), the oil companies' rules for their dealers under the dealership agreement, a mobile lab makes surprise checks. It draws nozzle samples of petrol and diesel from every tank and runs clinical tests: appearance, colour, density at 15°C and distillation, plus kinematic viscosity at 40°C for diesel MDG 2.4.4 MDG 7.1 MDG 7.4. The tests run whatever the density result. No further action is taken on a passing sample. For a failed one, meter and dip readings are recorded, the dealer is advised to suspend sales of that product, and the samples follow the chapter 2 route MDG 2.4.4 MDG 7.6.1.

The Marketing Discipline Guidelines 2024 (MDG 2024) are the oil companies' rules for their dealers, and bind dealers through the dealership agreement. This page is a plain-language explanation by MDG Services (a brand of VRUOOM Private Limited). It is not the official text and is not connected with or approved by IndianOil, BPCL, HPCL or any government body, so please check the current guidelines and circulars on the oil companies' own websites and with your oil company officer before you act.

Checked against the Marketing Discipline Guidelines 2024 (Ver. 1, effective 24.10.2024) on 15 October 2026. Published by MDG Services on 26 October 2026.

What happens at your outlet

The mobile lab draws nozzle samples of MS and HSD from every tank MDG 2.4.4 MDG 7.3.
It runs clinical tests: appearance, colour, density at 15°C and distillation, plus kinematic viscosity at 40°C for HSD. They run whatever the density result MDG 7.4.
If the sample passes, no further action is taken and the balance samples go back to the outlet MDG 2.4.4 MDG 7.6.

The limits follow the Indian Standards: IS 2796, IS 17586 and IS 17021 for petrol, IS 1460 and IS 16531 for diesel. They are revised from time to time, so check the current version of each MDG 7.6. The test report sets the density the officer measures beside the density you recorded for your tank after the last receipt, and prints a maximum variation of 3.0 kg/m³ between the two MDG Annexure 12a MDG Annexure 13a. If that record is missing at the visit, the officer still recommends action even when the sample passes MDG 5.1.9. See reference density.

If a sample fails

The officer notes the meter reading of every dispensing unit and the dip of each tank of that product in the test report (Annexure 12 for MS, Annexure 13 for HSD), and advises you to suspend sales of it. You sign every copy with the outlet seal MDG 7.6.1.
Three sets of 1-litre bottles are drawn: 6 per MS tank, 3 per HSD tank, on the Annexure 11 label MDG 2.4.4 MDG 7.5. You keep one set. The oil company keeps one and tests one, rather than sending it straight to the lab MDG 2.4.4.
The mobile lab hands the samples to the oil company's representative, preferably within 5 days. The supply location is phoned at once, so its depot sample is kept MDG 2.4.4.
The officer tells the State Level Coordinator straight away MDG 7.6.1(d). The coordinator and the oil company arrange to collect and test the related reference samples under chapter 2: see what happens when a sample fails MDG 7.6.

Two points are open, so confirm them with your oil company. MDG describes the suspension in three ways: advice to suspend the product MDG 7.6.1(b), suspension of sales and supplies by the mobile lab MDG 7.4 Note (ii), and suspension of all products by an oil company officer MDG 2.5(K). Chapter 7 also does not say how its rule on "established adulteration" MDG 7.4 Note (i) fits with the chapter 2 testing.

If you refuse

Refusing or obstructing a mobile lab's sampling or inspection is a major irregularity MDG 5.1.8. The minimum action is a 15-day suspension of sales and supplies the first time, 30 days the second time, and termination of the dealership the third time MDG 8.3.

Questions dealers ask

01What is a mobile lab at a petrol pump?

It is a testing unit that visits outlets to check petrol, diesel and lube samples by surprise. It works for the oil industry as a whole and carries the logos of all three oil companies, on a visit programme drawn up by the State Level Coordinator. An individual oil company may also run its own MDG 7.1 MDG 7.2.

02Can a mobile lab check my petrol pump without notice?

Yes. MDG gives surprise checks as the purpose of mobile labs MDG 7.1.

03Does the mobile lab pay for the fuel it takes as samples?

Yes. The outlet is paid for the quantity used in testing, and for the retained samples too if a sample fails. Keep the cash receipts MDG 7.3.1.

04Do I get a copy of the mobile lab test report?

Yes. Five copies are made and the outlet gets one. If a sample fails, the dealer signs every copy with the outlet's seal MDG 7.6.1.

Read the official text: Marketing Discipline Guidelines 2024 (PDF on Bharat Petroleum's website) (also published on iocl.com).

3-tier sampling at a petrol pump: who holds which sampleHow 3-tier sampling works under Marketing Discipline Guidelines 2024 (MDG 2024): the three samples, who draws and keeps each, and how long they are kept.

Fuel sample failed at a petrol pump: what happens nextWhat happens when a fuel sample fails under Marketing Discipline Guidelines 2024: how the lab decides, your re-test right and the deadlines that follow.

Inspector samples at a petrol pump: who, when, how manyWho may draw fuel samples at your pump under Marketing Discipline Guidelines 2024, when they do, how many bottles they take and what happens to them.

Morning density by 10 AM: the reference density ruleMDG 2024 makes a dealer record density by 10 AM each morning and after every tanker: which figure an inspector asks for, and what a miss costs.

About Dealer Kavach (advertisement)

Dealer Kavach is an app from MDG Services that tracks your outlet's filings, renewals, inspections and daily reports, and reminds you before deadlines, in Hindi and English.

About this page. This page is a plain-language explanation published by MDG Services, a brand of VRUOOM PRIVATE LIMITED (CIN U29194HR2021PTC098450). It is general information, offered free of charge. It is not the official text of any rule.

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Check the official source. The Marketing Discipline Guidelines 2024 (Ver. 1, effective 24.10.2024) and related circulars are issued by the oil companies. Rules, amounts and dates can change, and amendments may reach dealers directly without being public. Before you act, read the current documents on the oil companies' own websites (iocl.com, bharatpetroleum.in, hindustanpetroleum.com) and ask your own oil company's officer. If this page and the official document differ, the official document is the one to follow.

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