ADR question
Question asked to Palen
Revised on Jun 27, 2026 · Precision level : BOT_PROFILE_EXPERT
↗A packaged dangerous good belongs to **Transport Category 4** (ADR 1.1.3.6.3). Since the calculation factor is **0**, the transport is fully covered by the **ADR 1.1.3.6 small load exemption**. However, this dangerous good has a **Tunnel Restriction Code E** (for example, **UN0012**), while other dangerous goods also assigned to **Transport Category 4** have a **Tunnel Restriction Code (-)** (for example, **UN3077**). Can a vehicle carrying only this dangerous good under the ADR 1.1.3.6 exemption pass through a **Category E tunnel**? If so, why does the ADR still assign a **Tunnel Restriction Code E** to certain UN numbers in **Transport Category 4**? In which situations does this code still have legal effect? Is Tunnel Restriction Code **E** relevant only when the **ADR 1.1.3.6 thresholds are exceeded**, or are there other situations in which it applies despite the exemption?
Yes. A vehicle carrying only that packaged dangerous good under ADR 1.1.3.6 may pass through a Category E tunnel, even if the UN entry has Tunnel Restriction Code E, because dangerous goods transported in accordance with ADR 1.1.3 are expressly not subject to tunnel restrictions and are not taken into account for determining the tunnel restriction code of the transport unit, except for the specific limited-quantity marking case in ADR 3.4.13/3.4.14 (ADR 8.6.3.3, Volume 2, page 657; ADR 3.4.13–3.4.14, Volume 1, pages 645–646).
1. Why the Category E tunnel restriction does not apply under 1.1.3.6
ADR 1.1.3.6.2 provides that, when the 1.1.3.6 quantity conditions are met for dangerous goods carried in packages, Chapter 5.3 and Part 8 are not applicable except for the listed residual provisions; Chapter 8.6 is not one of those residual provisions (ADR 1.1.3.6.2, Volume 1, page 9).
ADR 8.6 then confirms the same result directly: dangerous goods transported in accordance with ADR 1.1.3 are not subject to tunnel restrictions and are not counted when determining the tunnel restriction code for the whole load, except where the transport unit must bear the limited-quantity mark under ADR 3.4.13, subject to ADR 3.4.14 (ADR 8.6.3.3, Volume 2, page 657; ADR 3.4.13–3.4.14, Volume 1, pages 645–646).
For Transport Category 4, ADR 1.1.3.6.3 includes Class 1, 1.4S, and gives the maximum total quantity per transport unit as “unlimited”; ADR 1.1.3.6.4 also omits Transport Category 4 from the mixed-load calculation, which is why it is often treated operationally as having a calculation factor of 0 (ADR 1.1.3.6.3, Volume 1, pages 10–11; ADR 1.1.3.6.4, Volume 1, page 11).
For example, UN0012 is listed in Table A as Class 1, classification code 1.4S, with special provision 364, limited quantity 5 kg, and packing instruction P130; the same UN0012 entry is assigned Transport Category 4 and Tunnel Restriction Code E (ADR 3.2, Table A, UN0012, Volume 1; ADR 3.3, SP 364, Volume 1, page 609).
2. Why ADR still assigns Tunnel Restriction Code E to a Transport Category 4 UN number
Column 15 of Table A has two separate functions: the number at the top of the cell is the transport category for ADR 1.1.3.6, while the code in parentheses at the bottom of the cell is the tunnel restriction code for ADR 8.6 (ADR 3.2.1, column 15, Volume 1, page 276).
The tunnel code is therefore not cancelled by Transport Category 4; it is simply not used while the goods are being transported under an applicable ADR 1.1.3 exemption, including 1.1.3.6 (ADR 8.6.3.3, Volume 2, page 657).
When tunnel restrictions do apply, Tunnel Restriction Code E means: “passage prohibited in Category E tunnels” (ADR 8.6.4, Volume 2, page 658).
ADR also provides that, if a transport unit contains dangerous goods with different tunnel restriction codes, the most restrictive code is assigned to the whole load (ADR 8.6.3.2, Volume 2, page 657).
3. Situations where the E code still has legal effect
Tunnel Restriction Code E has legal effect when the goods are not being transported under the ADR 1.1.3.6 small-load exemption and tunnel restrictions under ADR 8.6 apply, especially where orange-plate marking under ADR 5.3.2 is prescribed (ADR 8.6.4, Volume 2, page 657).
Typical situations include:
Mixed load exceeds the ADR 1.1.3.6 calculation: if the same vehicle carries other dangerous goods in Transport Categories 1, 2, or 3 and the calculated 1.1.3.6.4 value exceeds 1,000, the 1.1.3.6 exemption no longer applies to the transport unit; the tunnel code of the load must then be determined, and an E-coded UN number may make the whole load prohibited in a Category E tunnel (ADR 1.1.3.6.4, Volume 1, page 11; ADR 8.6.3.2 and 8.6.4, Volume 2, pages 657–658).
Transport is not in packages or otherwise does not meet 1.1.3.6 conditions: ADR 1.1.3.6.2 applies to transport in packages; if the transport operation is outside those conditions, the tunnel code in Table A can become operative through ADR 8.6 (ADR 1.1.3.6.2, Volume 1, page 9; ADR 8.6.4, Volume 2, page 657).
Limited quantities over the Category E tunnel trigger: ADR 8.6.3.3 creates a specific exception for transport units that must bear the limited-quantity mark under ADR 3.4.13, subject to ADR 3.4.14; those units are subject to Category E tunnel restrictions when the limited-quantity load exceeds 8 tonnes gross per transport unit (ADR 8.6.3.3 and 8.6.4, Volume 2, page 657; ADR 3.4.13–3.4.14, Volume 1, pages 645–646; ADR 1.9.5.2.2, Category E, Volume 1, page 93).
For UN0012 specifically, limited-quantity transport is also subject to special provision 364: UN0012 may be carried under Chapter 3.4 only if the package as presented for carriage can successfully withstand Test 6(d) of Part I of the Manual of Tests and Criteria, as determined by the competent authority (ADR 3.2, Table A, UN0012, Volume 1; ADR 3.3, SP 364, Volume 1, page 609).
4. Important correction on the UN3077 example
UN3077 is a good example of Tunnel Restriction Code “(-)”, but it is not Transport Category 4 in ADR Table A; it is shown with Transport Category 3 and Tunnel Restriction Code “(-)” (ADR 3.2, Table A, UN3077, Volume 1).
Where “(-)” is shown instead of a tunnel restriction code, the dangerous goods are not subject to tunnel restrictions, except for the special radioactive-material cases UN2919 and UN3331 (ADR 8.6.3.1, Volume 2, page 657).
Practical conclusion
A vehicle carrying only packaged UN0012, or another packaged Transport Category 4 dangerous good, under ADR 1.1.3.6 may pass through a Category E tunnel under ADR tunnel rules; the E code is not applied because ADR 8.6.3.3 removes 1.1.3 transports from tunnel restrictions (ADR 1.1.3.6.2, Volume 1, page 9; ADR 8.6.3.3, Volume 2, page 657).
The E code remains legally meaningful when the same UN number is part of a transport operation to which ADR 8.6 applies, especially full ADR/orange-plate transport, mixed loads no longer qualifying under 1.1.3.6, non-packaged operations outside 1.1.3.6, or the special limited-quantity >8 tonnes Category E tunnel case (ADR 1.1.3.6.4, Volume 1, page 11; ADR 8.6.3.2–8.6.4, Volume 2, pages 657–658; ADR 3.4.13–3.4.14, Volume 1, pages 645–646).
Sources:
- ADR 1.1.3.6.2 — Exemptions linked to quantities carried per transport unit, provisions not applicable under the small-load exemption, Volume 1, page 9.
- ADR 1.1.3.6.3 — Transport categories and maximum total quantity per transport unit, Transport Category 4, Volume 1, pages 10–11.
- ADR 1.1.3.6.4 — Mixed transport-category calculation, Volume 1, page 11.
- ADR 3.2.1, column 15 — Transport category and tunnel restriction code, Volume 1, page 276.
- ADR 3.2, Table A, UN0012 — Class 1, 1.4S, SP 364, LQ 5 kg, packing instruction P130, Transport Category 4 and Tunnel Restriction Code E, Volume 1.
- ADR 3.2, Table A, UN3077 — Transport Category 3 and Tunnel Restriction Code “(-)”, Volume 1.
- ADR 3.3, Special Provision 364 — Chapter 3.4 limited-quantity condition for the relevant articles, Volume 1, page 609.
- ADR 1.9.5.2.2 — Category E tunnel definition, Volume 1, page 93.
- ADR 3.4.13–3.4.14 — Limited-quantity marking on transport units and 8-tonne gross-mass threshold, Volume 1, pages 645–646.
- ADR 8.6.1–8.6.4 — Tunnel restrictions, tunnel codes, 1.1.3 exemption rule, and Category E prohibition table, Volume 2, pages 657–658.