Parking and supervising dangerous goods vehicles
Column (19) of Table A tells you whether the vehicle needs supervising. Chapter 8.4 tells you where you can park it.
In this guide
A few hours into the shift you need a break, and the services are full of cars and caravans. Can you leave a lorry loaded with dangerous goods there while you get something to eat? With most loads, yes. With some, ADR requires the vehicle to be supervised or parked only in certain places (ADR 8.4.1).
When a vehicle has to be supervised
Chapter 8.4 doesn’t list the goods it covers. You find that in column (19) of Table A in Chapter 3.2. If it shows S1 (for Class 1) or one of special provisions S14 to S24, Chapter 8.5 gives the quantity above which Chapter 8.4 applies (ADR 8.4.1). If none of them appears in column (19), there’s no supervision requirement under 8.4. Diesel (UN 1202) is an example.
| Provision | Supervision required for | Examples from Table A |
|---|---|---|
| S1 (6) | Class 1: above 0 kg or 50 kg net explosive mass, depending on the division | fireworks UN 0336 (1.4G): above 50 kg |
| S14 | any quantity | chlorine UN 1017, anhydrous ammonia UN 1005, solid potassium cyanide UN 1680 |
| S15 | any quantity, unless the load compartment is locked or the packages are otherwise protected against unlawful unloading | infectious substances UN 2814 and UN 2900 |
| S16 | above 500 kg | organic peroxide type B, temperature controlled, UN 3111 |
| S17 | above 1,000 kg | refrigerated liquid ethylene UN 1038 |
| S18 | above 2,000 kg | organic peroxide type C, liquid, UN 3103 |
| S19 | above 5,000 kg | methanol UN 1230 |
| S20 | above 10,000 kg in packages or 3,000 litres in tanks | petrol UN 1203, propane UN 1978 |
| S21 | any quantity, except with a locked load compartment and a limited dose rate | Class 7 radioactive material |
| S22 | above 5,000 kg in packages or 3,000 litres in tanks | stabilised acrylonitrile UN 1093 |
| S23 | above 3,000 kg or 3,000 litres in bulk or in tanks | ammonium nitrate based fertiliser UN 2067 |
| S24 | above 100 kg | azodicarbonamide UN 3242 |
The quantities are per vehicle. For S1 (6) it’s the net mass of explosive substance. The limit is 0 kg for divisions 1.1, 1.2, 1.5 and 1.3 with compatibility group C, and 50 kg for 1.3 other than C, 1.4 and 1.6. Fifteen Division 1.4 entries are an exception and have a 0 kg limit: UN 0104, 0237, 0255, 0267, 0289, 0361, 0365, 0366, 0440, 0441, 0455, 0456, 0500, 0512 and 0513. With mixed loads, the lowest limit of any item applies to the whole load (ADR 8.5, S1 (6)). Petrol (S20) shows how the thresholds work: a tanker with more than 3,000 litres has to be supervised, a van with a few jerrycans doesn’t.
The 1,000 points rule won’t always get you out of it either. Chapter 8.4, together with S1 (6), S14 to S21 and S24, still applies when the load stays under the 1.1.3.6 limit (ADR 1.1.3.6.2). A vehicle carrying a single small chlorine cylinder (S14) still has to be supervised or parked under 8.4.1.
Where you can park without supervision
Without supervision, such a vehicle may only be parked in a secure depot or on secure factory premises. If neither is available, you secure the vehicle properly and park it in an isolated position, in this order of preference (ADR 8.4.1):
- a) A vehicle park supervised by an attendant who has been told what the load is and where the driver can be found.
- b) A public or private vehicle park where the vehicle isn’t likely to be damaged by other vehicles. Only if there’s no park under a).
- c) A suitable open space away from the public highway and from dwellings, where the public doesn’t normally pass or gather. Only if there’s neither a) nor b).
Loaded MEMUs have their own rule. A MEMU is a mobile explosives manufacturing unit, which makes and loads explosives on site (ADR 1.2.1). It has to be supervised or parked in a secure depot or on secure factory premises. Empty uncleaned MEMUs are exempt (ADR 8.4.2).
Parking brake and wheel chock
Whatever column (19) says, no vehicle carrying dangerous goods may be parked without the parking brake applied. A trailer without a braking system has to be stopped from moving with at least one wheel chock (ADR 8.3.7). That’s the same chock that’s part of the equipment under 8.1.5.2.
Supervision and security under Chapter 1.10
Chapter 8.4 is about preventing accidents and damage to a parked vehicle. Chapter 1.10 is about theft and misuse. The two meet in three special provisions of Chapter 8.5:
- S16: vehicles carrying more than 500 kg of these substances, where they are subject to 1.10.3, must be constantly monitored in line with the security plan, to prevent malicious acts and to alert the driver and the competent authorities in case of loss or fire.
- S1 (6) and S21: the same for Class 1 goods and for radioactive material subject to 1.10.3.
For high consequence dangerous goods (Table 1.10.3.1.2), carriers, consignors and the other participants listed in 1.4.2 and 1.4.3 need a security plan. It has to assess the security risks of stops along the route, of keeping the goods in the vehicle before, during and after the journey, and of temporary storage (ADR 1.10.3.2.2 (c)). Devices that protect the vehicle and its load against theft must be used and kept working (ADR 1.10.3.3). Areas in vehicle depots, temporary storage sites and terminals used for temporary storage during carriage must be properly secured, well lit and, where possible and appropriate, closed to the public (ADR 1.10.1.3).
What you actually do as the driver
- Before setting off, check the UN numbers in the transport document and look in column (19) of Table A for S1 or S14 to S24.
- Compare the quantity on the vehicle with the threshold in Chapter 8.5. If you’re above it, plan your breaks in advance: depot, factory premises or a supervised lorry park.
- Whenever you park, apply the parking brake. Chock any trailer without brakes.
- At a supervised lorry park, tell the attendant what you’re carrying and where you can be found.
- With high consequence dangerous goods, follow your company’s security plan. Every crew member carries ID with a photograph (ADR 1.10.1.4).
Easy way to remember it: column (19) tells you whether. Chapter 8.5 tells you from what quantity. Chapter 8.4 tells you where: supervised park first, then a public or private park, then open ground. The parking brake always applies.
Practise the exam questions
The same points come up in the exam again and again: the order of parking places, who has to know about the load at a supervised park, and when the parking brake or a chock is required.
In the free test you get an explanation and the ADR reference after every answer. The app has more questions on Chapter 8.4 and the S provisions.
Sources
ADR 2025: 1.1.3.6.2, definition of MEMU in 1.2.1, 1.10.1.3, 1.10.1.4, 1.10.3.2.2, 1.10.3.3, column (19) of Table A in Chapter 3.2, 8.3.7, 8.4.1, 8.4.2 and special provisions S1 (6) and S14 to S24 in Chapter 8.5. In Great Britain, ADR applies through the Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2009. This guide explains the basics. For an actual journey, the wording of ADR is what counts.
Updated: 3 October 2026