Surface Cleaning Solvents – Why Vapour Pressure and Flash Point are Important

Cleaning hard metal surfaces to prepare them for painting, welding or inspection is a common and important task in some industries. For example, metal surfaces must be completely free of impurities and contaminants before welding or an unsatisfactory, sub-standard strength join will be achieved.

The process of surface cleaning is often a manual one, with powerful chemical solvents such as Acetone and MEK applied directly to surfaces to remove grease, contaminants, and staining. These common industrial solvents create workplace hazards and health risks to people who regularly use or come into contact with them.

Two important indicators that there are risks associated with surface cleaning solvents are high Vapour Pressure and low Flash Point.

Vapour Pressure

Vapour Pressure is a measure of the tendency of particles to escape from the liquid form of a chemical to an airborne vapour, at room temperature. It is an indicator of a liquid’s evaporation rate. Substances with a high Vapour Pressure such as Acetone and MEK readily release vapours into the air creating a number of health and safety issues.

Firstly, the release of vapour is often associated with fumes that are breathed in by workers and other people in the area where these chemicals are used. Not only do these fumes smell unpleasant, but chemical vapours can irritate the nose, throat, and airways and at high concentrations may cause drowsiness, headaches, breathlessness, nausea, dizziness, and confusion.

Inhaled vapour may also lead to other long term health implications depending on the toxicity of the chemical. For example, inhaled Toluene vapour – another common industrial solvent – may cause damage to the brain, kidneys, liver, nervous system and heart.

Secondly, a high evaporation rate creates significant product wastage. Surface cleaning solvents are only effective in their liquid state. This means that the more they evaporate, the more product is needed to complete the task. Using more product is not only more expensive, but it also increases the volume of unpleasant vapour released in the workplace.

Thirdly, volatile chemical vapours can gather and pool at points around the work area creating explosion and fire hazards, particularly if the chemical has a low flash point.

Flash Point

The Flash Point of a volatile chemical is the lowest temperature at which it can ignite in either liquid or vapour form. In general, chemicals which have a flash point that is higher than the environment (e.g. room temperature) will be at low risk of catching fire.

For example, a solvent with a flash point of 2 degrees Celsius is prone to ignition in almost any normal workplace. In contrast, a product with a flashpoint above 40 degrees Celsius would only be an ignition risk under quite extreme conditions.

An easy way to remember is the higher the flash point – the lower the risk.

Safely transporting, storing, using and disposing of flammable chemical solvents in the workplace creates many challenges to make sure the product is kept away from open flames, sparks, heat, static discharge, and other ignition sources.

Both Acetone and MEK have a low flash point which categorises these chemicals as flammable.

Identifying Chemical Hazards

Chemical hazards and risks for surface cleaning solvents are laid out in the product’s Safety Data Sheet (SDS), available on request from the distributor or manufacturer. By law, the SDS contains all relevant health and safety information relating to that product, including risks associated with chemical vapour and flammability.

You can read about Understanding an SDS (Safety Data Sheet) here.

Safer Surface Cleaning

Safer chemical substitution gives businesses the choice to avoid the health and safety risks associated with surface cleaning solvents with high vapour pressure and a low flash point. If a viable, safer chemical substitute exists, by law these must be investigated and implemented in the business. You can read more about Workplace Responsibilities and the Health and Safety Hierarchy of Controls in this article: Workplace Responsibility – Toxic parts cleaning solvents

Purasolve Surface Prep

Purasolve Surface Prep is a powerfully effective and safe surface cleaning solvent that is a suitable substitute for many products containing Acetone, MEK, Toluene and other dangerous and toxic chemicals. It is a unique low vapour, hydrocarbon degreasing solvent, which can be used in a wide variety of hard surface cleaning tasks.

Unlike MEK and Acetone, Purasolve Surface Prep has a low vapour pressure. It does not easily evaporate and is not an inhalation hazard under normal use. Low evaporation also leads to performance and costs benefits with extended contact time requiring less product compared to high vapour pressure alternatives.

Purasolve Surface Prep has a high flash point compared to MEK and Acetone. It is not flammable and non-explosive at room temperature. It is not reactive or corrosive and does not require complicated transportation, handling or storage procedures.

Purasolve Surface Prep has no known immediate or long term health effects. It does not contain chemicals that are proven or suspected carcinogens, mutagens or teratogens.

Find out more

See photos of how Purasolve Surface Prep performs compared to Toluene here: Bombardier De-Icing Rubber Boot Glue Removal | Comparing Purasolve Surface Prep & Toluene

Read a case study about how Purasolve Surface Prep helped eliminate the risks of Acetone in this workplace: Eliminating Acetone Explosion, Fire and Serious Health Risks in Steel Fabrication | Forgacs Tomago Shipyard