Solvents

Solvents are among the most commonly used chemicals in workplaces. Workers in different jobs regularly use solvents for degreasing, metal cleaning, and adhesion and as paint thinners or lubricants. Exposure to solvents can have both short and long-term health effects on workers.

Solvents are substances used to dilute or dissolve another substance to create a solution, and are widespread in workplaces.  While water is the most common solvent (many substances are easily soluble in water), some substances cannot be easily dissolved and require strong chemicals as solvents.

Most solvents used in industry are "organic", petroleum-based chemicals which have powerful properties to dissolve solids. They are often mixtures of several substances and can be extremely hazardous.

• Action Plan for Reps
• Advice for Workers
• Legal Standards
• Information on Solvents, including health effects and links

Action Plan for OHS Reps

As with all workplace hazards, solvents and other chemicals should be dealt with in this way:

1. Identification of the hazard 
2. Assessment of the risk
3. Elimination or reduction of the risk
4. Review and evaluation of any control strategies.

Advice for reps on your role in chemicals management and how to identify, assess and control the risks associated, go to Chemicals management in workplaces on this site.

Elimination or substitution of solvents

Solvent exposure should be controlled, like other hazards, according to the hierarchy of control measures, beginning with eliminating the substance. In other words, can the job can be done without using the hazardous solvent?

Organic solvents vary in the degree of risk they pose to health. Where possible the use of harmful solvents should be avoided and/or replaced with a less harmful product. For example, water-based solvents may be used instead of organic solvents. Sometimes the job may be done in a different way so that exposure to solvents is either eliminated or reduced.  If it can't be, use the following hierarchy in negotiotians with your employer.

Engineering Controls

If elimination or substitution is not suitable, engineering measures may need to be applied. Engineering controls may include:

• Using mechanical handling methods or automating the tasks.
• Local exhaust ventilation at the point where the solvent is used.
• Enclosing operations so that solvent exposure is isolated.
• Mechanical or general ventilation to dilute the workplace air (however this is not as effective as local exhaust ventilation to remove the contaminants).

Administrative Controls

When other approaches are not fully effective, certain administrative measures can minimise exposures. For example, prevent entry to areas where solvent vapour concentrations may build up by sign posting, limiting the amount of time workers spend doing certain jobs, etc.

Personal protective equipment (PPE)

If none of these control measures are suitable or are not effective in your workplace, appropriate personal protection should be provided for exposed workers:

• Protective clothing to cover all exposed parts of the body and personal clothing
• Boots, gloves, eye protection and suitable respirators to prevent splashes, skin contact and inhalation of vapours.

All personal protective equipment must be of a type suitable for the particular chemicals in the solvent.

PPE should be the final option in the hierarchy of control measures. It should be an interim measure until other controls are put in place.

In addition to the above, it is important that the employer:

• Provides information and training, and increases awareness of people who work with solvents.
• Ensures solvents are appropriately stored in a cool place, away from any potential ignition sources.
• Ensures the storage area is well ventilated and firmly secured.
• Ensures that solvent containers are properly labeled indicating the hazards of the substance and what should be done in case of an emergency.
• Ensures spills or leaks are contained with sand or other appropriate absorbents. Spillages must not be allowed to enter drains or other waterways.

Advice for workers

Do not use a substance unless you have been provided with adequate information about it and training in how to use it. All workers should make sure they know what the substance is, its effects, and how to use it correctly. They should have have the appropriate PPE if it is needed.

Workers should also practice good hygiene by washing hands well before eating, drinking, smoking or going to the toilet.  For this reason it is extremely important that the employer provides adequate facilities for washing, dining and so on.  (See our FAQ on Workplace Dinning Facilities)

Contact your union or the health and safety rep if you are unsure.

Legal Standards

The employer has a duty under the Victorian Occupational Health and Safety Act to identify, assess and control the hazards associated with the use of all chemicals, and as solvents are also classified as "hazardous substances" the requirements under Chapter 4, Hazardous Substances and Materials of the 2007 Occupational Health and Safety Regulations also apply. The employer must identify all hazardous substances, obtain the Material Safety Data Sheets (MSDSs), label containers appropriately, and control any risks to workers' health from using solvents.  These are legal requirements and may include air monitoring, blood or urine tests and proper training in working safely with chemicals. See the summary of the OHS Regulations Chapter 4.1 Hazardous Substances.  In addition, the General duties chapter of the Regulation also applies. 

Many solvents have exposure standards that must be complied with in the workplace. These standards indicate the permissible "airborne contaminant" levels of exposure, and, in some cases, ceiling levels to which workers may be exposed without causing detrimental health effects.

Under the legislation, the employer must take all practicable steps to eliminate or reduce the risks of exposure to the solvents.

More information on solvents

Some commonly used solvents, and their uses, are:

• Acetone (industrial coating)
• Trichloro ethylene (degreasing)
• Toluene (industrial coating, manufacture)
• Methylene chloride
• also known as dichloromethane (paint removal) 
• Methyl ethyl ketone (MEK) (printing ink)
• Perchloro ethylene (dry cleaning)
• White spirit (paints, printing ink, manufacturing)
• Ethylene glycol ethers (maintenance work; semiconductor industry)

How do solvents enter the body?

There are three ways that solvents can enter the body:

1. Inhalation: Most solvents are "volatile", ie they evaporate into the air very quickly. The fumes, dusts, gases and vapours that result can then be breathed in and easily passed through the lungs into the blood stream.
2. Ingestion: Solvent droplets can form in the hairs inside the nose, be sniffed in or swallowed. Mouth contact with contaminated hands, food and cigarettes can also result in the ingestion of solvents.
3. Skin Absorption: Solvents can be absorbed through the skin by direct contact and enter the bloodstream in this way.

What are the health effects?

Different solvents have different effects, depending on how exposure happens, how much and for how long. However, the effects of many solvents are still poorly understood.

Short-term effects can be caused by single exposures, often to a large amount of solvent. Short-term exposure can cause:

• dermatitis or skin problems (drying, cracking, reddening or blistering of the affected area)
• headaches
• drowsiness
• poor coordination
• nausea (feeling sick)

These effects usually take place very quickly. In cases of exposure to very high concentrations of solvent vapour, unconsciousness and even death can occur.

Repeated (long term) exposure to solvents may affect:

• the brain and the nervous system (see below)
• the skin - causing dermatitis
• the liver - causing liver damage
• the blood-forming system
• the kidneys
• the fertility of both men and women
• the foetus in a pregnant woman and increased likelihood of spontaneous abortion

Some solvents, for example, benzene, can cause cancer.

Some solvents will have synergistic effects with other hazards and drugs. This means that the solvent will have greater health effects when it is in combination with other hazards. For example, after using an organic solvent, the effects from exposure will be greater if the person smokes cigarettes or drinks alcohol soon afterwards.

Effects of solvents on the nervous system

There has been increasing attention on the damage to the nervous system from solvent exposures. This is called neurotoxicity. It may be short-term (usually with high exposure and rapidly reversible once exposure has ceased) or long-term. Chronic (or long-term) effects are caused by degeneration of parts of the nervous system because of repeated low level exposures.

Symptoms of neurotoxicity are:

Tests for neurotoxicity

There are useful tests to identify toxic effects on the peripheral nerves. Nerve conduction studies (NCS) and electromyographic studies (EMG) are used in cases where there is tingling or numbness of the hands or feet, or associated muscle weakness.

A set of neuro-psychometric tests has been developed to find behavioural effects. They include tests for:

• Motor speed
• Hand steadiness
• Perceptual speed
• Reaction speed, eye-hand coordination and manual dexterity
• Verbal and visual memory and learning
• Cortical evoked potentials (electrical activity in the brain following sensory stimulation)

Contact your doctor or your union for more information regarding these tests.

Who is at risk?

Few industries are free of solvents but workers in the following industries may be particularly at risk:

• Cleaning
• Dry cleaning
• Chemical manufacturing
• Footwear
• Plastics
• Printing
• Spray painting
• Semi-conductor industry
• Maintenance of machinery

See Also

• The following guides are available on the Safe Work Australia site (they were developed some time ago, but still provide useful information): 
  • Industrial Organic Solvents - outlines some of the potential health hazards associated with the handling of industrial organic solvents. It also addresses the control of these hazards.
  • Solvent Vapour Degreasing  - addresses the occupational health and safety aspects of solvent vapour degreasing. The harmful effects of solvents follow inhalation of vapour, eye and skin contact with liquid or vapour or ingestion.
• A series of hazardous substances checklists are in the Toolkit - useful for the workplace.
• A 2008 report done in the Netherlands: Occupational exposure to organic solvents: effects on human reproduction The report is in both Dutch and English

Important Chemicals Information