Product Chemical Hazard Labels Explained

Hazard pictograms inform of the dangers of certain chemicals and help users take precautions. If safety information is not displayed correctly, then manufacturers and/or employers can be held liable for any accidents.

There are many places that use chemicals on a daily basis, including: schools, laboratories, universities, and colleges. Even cleaning products contain dangerous chemicals; therefore, everyone should learn about hazards and precautions.

This page provides details on the changes to the law and how they will affect those who use dangerous chemicals. It also details the new labelling system and the meaning of each of the pictograms.

New Chemical Legislation

From the 1st June, 2015, the CLP regulation will replace all of the current legislation regarding the classification of chemicals. The act is based on the Globally Harmonised System (GHS) – a United Nations initiative to create a universal chemical classification system.

The new legislation requires all manufacturers conform to the GHS. Lots of products will need to be relabelled before 2017; however, this means that many household products will still bear the old pictograms introduced in 1997.

The new legislation has implications for users of chemicals, such as schools, laboratories and universities, who will have to adapt to the changes by changing safety information to conform to the new legislation.

Who is affected by the New Legislation

Manufacturers are responsible for the labelling of their products; however, employers will need to incorporate the new pictograms and guidelines into their safety information. Laws regarding the use of chemicals at work, or COSHH (details of which can be found here), still apply. For more advice on the new legislation, the University of Edinburgh provides an array of resources and safety data sheets here.

GHS Symbols and their Meanings

Each one of the new GHS pictograms symbolises a potential hazard. They are usually accompanied with a supporting precautionary statement or details of treatments.

If any accidents occur, always seek immediate medical attention regardless of the instructions on the label. Complications can develop weeks after exposure, and not all chemicals induce symptoms.

Shown below are the new pictograms, complete with their meanings and the relevant precautions to take.

“Contains gas under pressure”

Contains gas under pressureContainers bearing this symbol are pressurised, such as fire extinguishers and gas canisters. They contain gases that can explode if heated. It also applies to products containing refrigerated gases, which can cause serious cryogenic burns when exposed to skin.

Precautions: Pressurised gas containers should always be protected from heat sources and direct sunlight. When emptying a pressurised container, protective eyewear, a face shield and insulating gloves should be worn.

 “Serious Health Hazard”

Serious Health HazardThis pictogram symbolises hazards related to respiratory and general internal health. This symbol will always come with another more detailed written warning. Potential hazards include: fatal damage to organs, fertility damage, genetic defects, and breathing difficulties. Products such as turpentine, petrol and some types of oil will bear this symbol.

Precautions: This symbol will usually be accompanied with a precautionary statement, such as “Do NOT induce vomiting” and “Do not breathe dust/fume/gas/mist/vapours/spray”. This type of product should always be used in a well ventilated area. Vomiting is not recommended as a treatment because some chemicals, such as certain cleaners, can cause burns to the throat. Also, hospitals have more effective methods to remove poisons from the stomach.

Symbols to be phased out: Health Hazard old symbolHarmful to the Ozone Layer old symbol

“Health Hazard/ Harmful to the Ozone Layer”

Health Hazard

This symbol is generally reserved for household items, such as bleach, washing detergent and toilet cleaner. Products with this symbol can also cause serious environmental damage if not disposed of properly.

Precautions: Always wear eye protection, facial protection and protective or waterproof gloves (such as Marigolds) when using products with this pictogram. Even relatively mild cleaners can aggravate skin conditions after prolonged exposure.



Not all explosive materials will bear this symbol: deodorant cans and gas canisters may still explode but may not be labelled as explosive. This is because this symbol is only used on items with mass explosive power or unstable explosives, such as live ammunition and fireworks.

Precautions: Explosive materials should be stored in locked cabinets and kept away from heat sources. For items such as fireworks, a reasonable distance should be kept between the spectators and the explosives. Guidelines on fireworks safety can be found here. Guidelines on storing explosives, especially ammunition and weapons, can be found here.

Symbols to be phased out: Explosive old symbol



Materials bearing this symbol can be easily set on fire. Even vapour can be set alight if proper precautions are not taken. The reason why mobile phones cannot be used in petrol stations is because the vapour can be ignited by static electricity. Typical items that bear this symbol are nail polish removers and deodorant cans.

Precautions: Materials of this kind should be kept away from sources of heat and direct sunlight. Deodorant should never be sprayed onto an open flame as the fire can travel back through the can and ignite the contents. Never smoke around products bearing the flammable or explosive pictograms.

Symbols to be phased out:

Flammable old symbol




Oxidising products may cause or intensify fire. Oxidising materials can also cause explosions; therefore, they should be treated as flammable. Oxygen tanks and some household cleaners, such as bleach and turpentine, will bear this symbol.

Precautions: Protective clothing, such as gloves and eyewear, need to be worn when handling this oxidising materials. Also, exposed clothing needs to be washed thoroughly to avoid setting them on fire.


Symbols to be phased out:

oxidising old symbol





Corrosive material can be damaging to skin and some types of metal. Some cleaners and acids commonly used in schools, such as hydrochloric acid and ammonia, are corrosive.

Precautions: Some chemicals can react with water and cause burns. Therefore non-reactive protection must be worn when handling any corrosive materials. If exposure does occur, this resource on the NHS website recommends that the exposed brush their skin and/or wash it with water and immediately remove all contaminated clothing. Medical professionals need to be made aware of the substance so they can find a suitable treatment.

Symbols to be phased out:

oxidising old symbol

 “Acute Toxicity”

acute toxicity

Toxic substances can be fatal if they come into contact with skin, are inhaled or are ingested. This can be from a single exposure or multiple exposures over a 24hr period. Most products described as acutely toxic produce symptoms within 14 days of exposure. Typical products bearing this symbol include biocides and pesticides. Not everyone reacts the same to toxic substances and they have been known to cause instant death in some and few symptoms in others.

Precautions: Anyone exposed to toxic chemicals should wash themselves to get rid of any trace amounts of the toxin. All contaminated clothing should be thoroughly washed or destroyed. All of this should take place in a well ventilated area, away from others. If a toxic substance is inhaled, those exposed should be taken outside for fresh air until the emergency services arrive.

Symbols to be phased out:

Harmful to the Ozone Layer old symbolHealth Hazard old symbol

 “Hazardous to the Environment”

Hazardous to the Environment

Environmental spills are very difficult to clean up and can have long lasting effects on the animal population. Pesticides and biocides are the most common products to bear this pictogram.

Precautions: Most chemicals can be disposed of at facilities that provide chemical recycling and disposal. In places such as laboratories, schools and universities, chemicals should be disposed of down dedicated drains and the tanks should be regularly emptied by a certified chemical disposal company. Disposal of chemicals in rivers or public drains is illegal and dangerous.

Chemicals in Schools

Manufacturers are responsible for hazard labelling, but schools are responsible for the safety of their students and staff. The curriculum for primary and secondary schools requires children to use harmful chemicals, so before carrying out any work with chemicals, schools will need to be risk assessed. This should be done by staff qualified to handle the chemicals in use.

In school laboratories, all materials should be locked in a cabinet or a locked room with limited access for certain staff only. All areas that contain chemicals should contain an up-to-date itinerary of all materials and an up-to-date first aid kit adapted for chemical burns.

Some organisations, such as CLEAPPS, provide support and courses to teachers, parents and anyone who is works with dangerous chemicals. They recommend that teachers and parents involve their children when they are risk assessing, possibly including it in their lessons. Staff should also be engaged in risk assessment. There could be legal consequences for schools if their staff have not be properly trained to handle chemicals, including cleaning products.

For more information on chemical safety in schools, this resource provides some ideas on improving classroom safety and conforming to legislation. The .GOV website contains details relating to specific pieces of legislation and how they can affect different groups.

Information for Parents whose Children Work with Chemicals

Parents whose children suffer from health conditions, especially eczema and asthma, should inform their child’s school of their conditions. Many chemicals release vapours that aggravate respiratory and skin conditions.

If a child does suffer from any health conditions, a thorough risk assessment should be carried before they participate in experiments. Sometimes, lessons can be changed so all children can participate; However, when this is not possible, alternative arrangements should be made for the child.

It is a schools responsibility to provide safety information and clothing during lessons, but teaching children how to be responsible around chemicals starts at home. Most household cleaning labels will contain at least one of the pictograms explained above, because many products were made before the new legislation took effect.

Children should work with chemicals (including household cleaning products) in a well ventilated area and always under the direct supervision of an adult.

Other Resources for Individuals and Employers

The government provides a host of resources for individuals and employers to help make the transition to the new CLP regulations easier. Resources like this provide information for employers about educating employees and what health and safety sheets need to be displayed in the workplace.

For information on specific poisons, how to treat acute poisoning and poison centres across the UK, visit the National Poisons Information Service. The NHS can be contacted for advice on poisons and as a non-emergency contact on 111. In an emergency, the NHS should always be contacted on 999.

For specific information regarding children and toxic substances in the home, the NPIS provides these guides to help parents take the necessary precautions.