Before we can discuss how to manage chemical hazards, we must first understand what are classified as hazardous chemicals.
What are hazardous chemicals?
Hazardous chemicals are substances, whether an element or compound form, that are poisonous, injurious or a threat to health. Some are highly corrosive and reactive. Others are carcinogenic. They could be solid, liquid, or gas. They can also be in a mixture or a suspension.
These chemicals could range from common household items like cleaning fluids to industrial reagents used in manufacturing various products like fertilizers and chemical weapons. Different types of hazardous chemicals have specific regulations.
Hazardous chemicals are regulated in various ways:
- Manufacturing – regulations may include safety protocols for workers, machine inspections, and environmental impact
- Storage – some chemicals require specific storage containers and internal climate control within the storage facility. For example, temperature and humidity may have to be precisely controlled to properly store volatile and flammable chemicals
- Transportation – industrial raw materials need to be transported from a source or sources to the factory. In a similar manner, finished products must be transported to the buyers or to another factory for further processing. It is during transportation that the risk of spillage is relatively high. Certain regulations about transport containers and trucks come into play. There are also rules on clean-up in case of spillage and other legal accountabilities
- Sale – some chemicals are restricted to be sold only to a limited list of buyers such as government agencies or are totally prohibited in certain jurisdictions
- Applications – chemical ingredients and finished products are usually heavily regulated for safety reasons. This is especially true for explosive chemicals, corrosive chemicals, and flammable chemicals
The Control of Substances Hazardous to Health (COSHH) is a set of regulations enforced by the Health and Safety Executive in the UK for the workplace. It covers the following:
- Products containing chemicals
- Gases and biological agents. If the packaging has any of the hazard symbols then it is classed as a hazardous substance
- Germs that cause diseases such as leptospirosis or legionnaires disease and germs used in laboratories
However, the following substances are not part of COSHH regulations: asbestos, lead, and radioactive substances. These substances have their own specific regulations.
Toxic levels of water
Technically, all chemicals, including water, are toxic when ingested in excessive amounts. Water intoxication or poisoning can occur when too much water is drunk. It causes the disruption of brain functions.
When there is excessive water in the blood, minerals, and electrolyte can be diluted to a critical level. Sodium is particularly important in many bodily functions like muscle contraction and the electron transport system in the brain. If sodium in the blood falls below 135 mmol/L, cells will start to swell as osmotic pressure shifts.
The following are some of the common symptoms of water intoxication:
- Increased blood pressure
- Double vision
- Difficulty breathing
- Muscle weakness and cramping
- Inability to identify sensory information
Different organisms have different susceptibility
You should not ingest hazardous chemicals even in very small amounts because they have a higher level of toxicity. Any chemical that can cause poisoning of a human in small amounts is considered hazardous.
That said, a chemical that is hazardous to humans is not necessarily hazardous to other organisms. For example, synthetic fertilizers are harmful to humans but they are very useful to plants.
Conversely, there are chemicals that are not hazardous to humans but hazardous to other organisms. For example, the delicious chocolate bar we all know and love can be dangerous to dogs.
That’s because chocolate is derived from cacao plants that contain a bitter alkaloid component called theobromine. This is toxic to dogs. Even a small amount can cause diarrhoea and vomiting in dogs.
Some hazardous chemicals do not need to be ingested for them to cause harm. Household items like cleaners and de-clogging liquids can irritate and even burn the skin when improperly handled. De-clogging liquids are base solutions with highly corrosive active ingredients like sodium hydroxide.
How do you dispose of hazardous chemicals?
The United Nations classifies hazardous substances according to the following categories:
- Class 1: Explosives
- Class 2: Gases
- Class 3: Flammable liquids
- Class 4: Flammable solids
- Class 5: Oxidising substances
- Class 6: Toxic substances
- Class 7: Radioactive material
- Class 8: Corrosive substances
- Class 9: Miscellaneous dangerous substances
The disposal of hazardous chemicals varies depending on its type. Explosive chemicals, for instance, are either purposely detonated or neutralised into inert compounds. Radioactive materials, on the other hand, require special lead containers and are buried deep underground.
Highly radioactive waste materials are disposed of in specialised repositories deep underground in geologically stable locations with natural barriers such as salt and rocks.
Similar to storage, the disposal of hazardous materials must be carefully carried out following specific protocols depending on the type of chemical and the hazard it poses. Human health and environmental safety are the main factors considered.
What type of gloves protect your hands from hazardous chemicals?
Again, the type of gloves that you should use when handling hazardous chemicals will directly depend upon the type of chemical. Some chemicals cannot be handled simply by wearing gloves. For example, highly radioactive materials are typically handled using robotic arms and hands.
The following are the types of gloves you should use for specific types of chemicals:
- Rubber gloves – for mildly corrosive chemicals like diluted hydrochloric acid and lye
- Nitrile gloves – can protect against most chemicals and pathogenic agents
- Neoprene gloves – can provide protection against most solvents, oils, and mildly corrosive substances
Why are hazard symbols used on chemical containers?
Hazard symbols are pictographs that serve as warnings for specific types of potential danger or hazard. These are part of the labels of containers or facilities that store dangerous substances. They are relatively easy to understand based on the common usage in a particular culture.
In the UK, some of the most common hazard symbols used by industries and institutions include:
- Explosive chemicals (exploding bomb)
- Flammable chemicals (flame)
- Oxidising chemical (flame over circle)
- Corrosive chemicals (corrosion)
- Acutely toxic chemicals (skull and crossbones)
- Environmentally damaging chemicals (dead tree and fish)
How to prevent contamination from chemical hazards
Hazardous chemical contamination may either come from nature, such as in the case of radon gas poisoning from underground, or it may come from synthetic or man-made sources, such as an oil tanker spilling oil and polluting the ocean.
If you think about it, there are always risks but not on the same levels. Strict enforcement of regulations and safety protocols significantly minimise the risks. However, you can also do something to prevent contamination from chemical hazards.
Here some precautionary measures you can take, both at work and in the home:
- If you are working in a factory with hazardous chemicals, wear the relevant protective gear
- Always follow your company’s safety protocols
- Secure food items in sealed containers and maintain proper refrigeration
- Thoroughly clean food ingredients and kitchen utensils
- Store dangerous household chemicals like cleaning fluids and antifreeze in a safe place
- Always practice good hygiene like hand washing before and after eating
Preventing contamination of hazardous chemicals is all about vigilance. It is not only the responsibility of corporations and government regulators but also a responsibility of ordinary citizens.
All content published on the ReAgent.ie blog is for information only. The blog, its authors, and affiliates cannot be held responsible for any accident, injury or damage caused in part or directly from using the information provided. Additionally, we do not recommend using any chemical without reading the Material Safety Data Sheet (MSDS), which can be obtained from the manufacturer. You should also follow any safety advice and precautions listed on the product label. If you have health and safety related questions, visit HSE.gov.uk.