• A TR Group Site
  • Help
  • Cart
Driving Tests DT logo small
Driving tests
  • Learner licence
    • Car
    • Motorbike
    • Heavy vehicle
    • Learner Licence Plus
  • Courses
  • Tourist
  • Resources
  • Learn
  • Resources
  • Learner licence
    • Car
    • Motorbike
    • Heavy Vehicle
    • Learner Licence Plus
  • Your courses
    • Enrolled courses
  • View all courses
  • Tourist
  • Resources home
  • iOS application
  • Android application
  • Contact us
  • Terms and conditions
  • Privacy
  • Home
  • /
  • Resources
  • /
  • Dangerous goods
  • / What type of dangerous goods need two placards on the vehicle?

What type of dangerous goods need two placards on the vehicle?

Some chemicals need to be placarded for both a primary and subsidiary risk. Both the primary and subsidiary risks must be considered when segregating incompatible dangerous goods, unless they are gas bottles being transported using appropriate equipment, in which case the subsidiary risk can be ignored.

B-trains with multiple placarding options (primary and subsidiary for each of the two trailers)

The following examples represent just a few; there are many more.

  • UN 1053 Hydrogen Sulphide has a primary risk of 2.3 and a subsidiary risk of 2.1
  • UN 1070 Nitrous Oxide has a primary risk of 2.2 and a subsidiary risk of 5.1. It is used for pain relief and as a sedative.
  • UN 1079 Sulphur Dioxide has a primary risk of 2.3 and a subsidiary risk of 8. It’s produced when burning fossil fuels. It is used to manufacture sulphuric acid, paper and food preservatives
  • UN 1230 Methanol has a primary risk of 3, a subsidiary risk of 6.1 and a packing group II. It is used in thousands of everyday products such as plastics, paints and construction materials.
  • UN 1360 Calcium Phosphide has a primary risk 4.3, a subsidiary risk 6.1 and a packing group I. It’s used to kill rodents, as well as to make explosives and fireworks.
  • UN 1436 Zinc Powder has a primary risk of 4.3, a subsidiary risk 4.2 and packing groups I, II and III. It’s used as a galvanising anti-corrosion treatment for steel.

If we use the example of methanol, its main risk is flammability, but it is also toxic.

Packing group I is high danger, packing group II is medium danger and packing group 3 is low danger. The precedence works in that order.

In terms of the precedence with the hazard class, it follows this order, unless specified:

  1. Class 7 radioactive (except when in excepted packages)
  2. Class 1 explosive
  3. Class 2 gases
  4. Class 3 liquids
  5. Class 4.1 solids
  6. Class 4.2 solids
  7. Class 5.1 oxidisers
  8. Class 6.1 toxic, or class 3 liquids, with packing group I by inhalation
  9. Class 6.2 infectious substances.
By Darren Cottingham

Darren has written over 3000 articles about driving and vehicles, plus almost 500 vehicle reviews and numerous driving courses. Connect with him on LinkedIn by clicking the name above

‹ How does the weather affect the range and performance of an electric vehicle?
Are camera wing mirrors better than traditional glass wing mirrors? ›
Tagged with: dangerous goods | Posted in Dangerous goods
  • DisqusDisqus
Recent Resources
  • How do you operate an excavator safely in the rain?
  • The Impact of Weather Conditions on Safe EWP Operation
  • Acoustic Emission Testing for Fibreglass Booms: Why It Matters
  • The Evolution of Gantry Cranes in Modern Manufacturing
  • Understanding Load Capacity and Weight Distribution on EWPs
  • How do you efficiently dig a trench? Tips from the pros
  • How to Choose the Right EWP for Your Project: A Comprehensive Guide
  • Pre-Operational Inspection Checklist for Gantry Crane Operators
  • The Importance of Harness Systems When Working on Boom Lifts
  • Safety Procedures for Working Near Power Lines with EWPs

Licences and Courses

  • Car
  • Motorbike
  • Heavy Vehicles
Car
  • Core
  • Behaviour
  • Parking
  • Emergencies
  • Road position
  • Intersection
  • Theory
  • Signs
Motorbike
  • Bike-specific questions
  • Core
  • Behaviour
  • Parking
  • Emergencies
  • Road position
  • Intersection
  • Theory
  • Signs
Heavy Vehicles
  • Class 2
  • Class 3-5
  • Core
  • Behaviour
  • Parking
  • Emergencies
  • Road position
  • Intersection
  • Theory
  • Signs

Vehicle and workplace training

  • About
  • Resources
DT Driver Training TR Group
About
  • About us
  • Contact us
  • Privacy Policy
  • Terms and Conditions
Resources
  • Homepage
  • Driving Tests Android App
  • Driving Tests iPhone App
  • Getting your learner licence
DT Driver Training TR Group
Copyright 2010-2025 DT Driver Training Ltd, PO Box 12541, Penrose, Auckland, 1642. All rights reserved. Questions and images are used with permission from NZTA; question answers are proprietary.