HGV Warning Signs and Symbols

If you drive a truck or HGV, you’ll be well aware of the various signs and symbols that these heavy-duty vehicles come with. Different trucks will feature different symbols depending on what they are transporting, and it’s important to understand what they mean.

At The Windscreen Company, we regularly provide windscreen repairs and replacements for customers across the West Midlands and the South East who drive these vehicles, and in this article, we’ll take a closer look at these signs and what they mean. 

HGV warning signs and symbols

There is a wide range of warning signs and symbols that apply to HGVs. They come in various categories as follows:

Large vehicle rear markings 

All vehicles that are 7,500kg gross weight or more, and trailers that are 3,500kg gross weight or more, must display these rear markings. The purpose of these markings is to make them more visible to other road users as they can be more hazardous. 

Hazardous warning plates

All trucks that are transporting hazardous goods must have hazardous warning plates attached to their vehicle. These plates will include two codes and the appropriate hazard symbol. The three-digit code at the top is the Emergency Action Code (EAC) that needs to be provided to emergency services in the event of an accident. The emergency services use a specific code to make quick assessments during emergencies, and this will help them determine the best course of action. The four-digit code below the EAC is the UN number that identifies the substance being transported. The hazard symbol is used to identify the type of substance in the HGV, with each material given a class rating from 1 to 9. 

Diamond hazard symbols 

There are nine diamond hazard symbols, with each depicting the type of material being transported. The appropriate one must be used alongside the hazardous warning plate. These are as follows:

Explosives – Class 1

 

Class 1 is for explosive hazards that are being moved, such as ammunition, fireworks and certain chemicals. Each explosive is given a rating between 1.1 (extremely sensitive explosive) to 1.6 (insensitive explosive).  

Gases – Class 2

 

This symbol is for gases, like propane, oxygen or carbon dioxide, that are being moved. Gases are categorised in three forms, flammable, non-flammable and toxic, with each given a class between 2.1 to 2.3.  

Flammable liquid – Class 3

Flammable liquids are categorised as substances that have a flashpoint below 61°, meaning they are more likely to ignite from a spark. These liquids must only be transported by qualified drivers and include the likes of petrol.  

Flammable solids – Class 4

Class 4 refers to flammable solids, and they come in three categories:

• 4.1 – solids that may ignite through friction or self-reactive substances 
• 4.2 – solids that may combust when they come into contact with air
• 4.3 – solids that may combust when they come into contact with water

Oxidising and organic peroxide – Class 5

These are substances that increase the risk of fire due to the large amounts of oxygen they are made up of. Typically, these substances are dangerous if they come into contact with fertilisers or organic peroxides. 

Poison – Class 6

A substance is classified as poisonous if it can cause human harm when ingested, inhaled or by skin contact. This also includes bacteria, viruses, fungi and parasites.

Radioactive – Class 7

A Class 7 hazard refers to materials that have radioactive properties, like uranium. In some cases, the transportation of such substances may even require a police escort for additional safety.

Corrosive – Class 8

Class 8 refers to solids or liquids that can harm or damage human skin and other materials. Usually, corrosive substances react violently when they come into contact with water. A common example of a corrosive substance is sulphuric acid.

Miscellaneous – Class 9

Any other harmful materials that do not naturally fall into the other eight categories are classified as a Class 9 miscellaneous hazard. The most common example of this is asbestos. 

Truck and HGV windscreens 

If you or your business relies on trucks or HGVs to transport any type of goods, hazardous or not, it’s essential that your vehicle is always kept in the best condition. This includes windscreens, and here at The Windscreen Company, we provide a windscreen repair and replacement service for all commercial vehicles that will get you moving again as soon as possible. Furthermore, we’ll make sure your vehicle is always VOSA compliant, and we even offer an emergency service that ensures we’ll be by your side when you need us most. 

To find out more, contact our team today for a free quote.