Soaking up spills

When we talk about oil spills, we tend to think about the Exxon Valdez or the more recent Antarctica oil spill. While these incidents cause much serious environmental, health and safety problems and pollution, the biggest source of spills into the sea is from urban and industrial outputs which result in similar consequences.

Not all oils are considered as hazardous substances under OHS laws. &quotMineral oils are not generally classified as dangerous goods but are regulated under the Dangerous Goods regulations," said Peter Knott, senior occupational hygienist, Occupational Health and Environmental Safety Division, 3M Australia. &quotOils are considered as substances which can harm the environment."

In an industrial setting, hydrocarbon-based liquids which are typically spilled substances include petrol, diesel, kerosene, turpentine, lubrication oils, hydraulic fluids and mineral oils. The US National Research Council has estimated a worldwide total of 960,000 tonnes of oil entering the sea comes from urban and industrial settings each year.

&quotIronically, land-based oil spills probably account for 90% of all oil released into the environment, yet receive very little funding for spill prevention, control and clean-up, whereas maritime oil spills, which account for only 10%, receive enormous resources," Christopher Aebi, director of technical services at Enretech Australasia, says.

&quotAs a general rule, it has been my experience that liquid spills typically result where liquids are handled, such as being dispensed, transported, packaged and applied.

&quotOn occasion, liquids are spilled from process piping or other containment vessels in automated systems however, many incidental and emergency spills have direct human causes."

Of course, the nature of a spill is dependent on the way oil is used within a plant. &quotTypical examples of likely scenarios include hydraulic hose failure, incidental spills while decanting and accidents such as a drum being punctured by a forklift," Phil Abernethy, managing director of Absorb Environmental Solutions, says.

Other circumstances which can lead to spills include overfilling lube tanks, ruptured tanks, leaks from gearboxes, lubricating systems and the discharge of oil-contaminated stormwater or process water.

All these occurrences could lead to the release of oil into the environment and waterways as well as cause damage to property and equipment and create an unsafe workplace.

By law, every workplace must conduct risk assessments to identify the hazards and risks pertaining to spilling liquids. Suitable controls must then be implemented to mitigate the risk.

&quotThere are two main safety risks associated with an oil spill the slip hazard created when oil spills across a traffic area and the fire hazard associated with oil being a combustible material," Abernethy said.

Aebi says that in general, petroleum hydrocarbons have different effects depending on the compound and the conditions. &quotTaking diesel as an example, a spill of 1 L on a bitumen surface will have minimal risk and can be easily cleaned up.

&quotHowever, if the volume was 100 L, slip hazards, release to the environment, possible entry into waterways, potential inhalation exposure of hydrocarbon vapours to cleaners and many more hazards and risks must be considered.

&quotThese considerations, questions and resulting answers are all a part of the risk assessment process."

Response and reporting

A grey area in spill response is whether a spill needs to be reported and who to report to. The Environmental Protection Authorities of each state must be notified if the spill is a ''pollution incident'' which will harm the environment, while WorkCover authorities need to be notified if there is a work-related incident.

Abernethy recommends that spills should be internally reported regardless of whether an injury was sustained. &quotThe main reason to report a spill is to prevent them from reoccurring.

&quotIncidents may only need reporting to a supervisor rather than to a government agency."

When a spill does occur, there is more than one way to deal with it. &quotAll OHS and environmental regulations require liquid spills to be cleaned up but none of them tell you how," Abernethy says. &quotThere is, however, the Australian Standard 1940:2004 which is relevant for the storage and handling of flammable and combustible liquids.

&quotThis standard specifies that spill response equipment should be available and staff trained in the correct procedures to handle spills and other emergencies."

These standards do not go into detail about spill response or how to go about containing or cleaning a spill nor is there regulation or legislation in Australia about how someone should respond to a spill.

&quotThe Workcover Act and regulations pertain to the creation and maintenance of a safe workplace, not how you specifically achieve this. That''s up to you," Aebi says.

&quotThe basic technique for dealing with spills is absorption," Abernethy says. &quotTen years ago and even still today, mineral absorbents like ''kitty litter'' or diatomaceous earth are predominately used as oil absorbent. This is despite such material being unsustainable, costly to dispose of, unsuitable for landfill and in some cases carcinogenic."

Aebi says that old habits die hard and there has been a resistance to change from inorganic and synthetic absorbents, even though both cost and environmental benefits could be shown.

Environmentally sound sorbents

Absorbents can be generally classed into 3 categories: organic, inorganic and synthetic. With the rise of environmental awareness and responsibility, sorbents of choice have moved towards greener options.

&quotBy comparison, organic absorbents are now seen as the preferred option from an eco-friendly perspective, although inorganic and synthetic absorbents still have their roles to play in certain situations," Aebi says.

&quotWithin the organic sorbent community, those derived from waste by-products of certain industries are preferred as they solve both a waste problem in their originating industry as well as a waste problem elsewhere. And the resulting final waste material can often be biodegraded back to natural, useful, compounds."

Abernethy suggests that environmentally friendly spill control consists of products which meet the follow criteria:

• The absorbents are made from recycled materials.
• The absorbents are made from sustainable material such as cellulose, which is a renewable material.
• The absorbents are biodegradable. This means that they will break down over time and be consumed by microorganisms.
• The absorbents are bioactive. This means that the absorbents already have oil-eating microorganisms in them. This accelerates the conversion of the oil and absorbent to biogas.
• The product can be re-used.
• The packaging material is either biodegradable or recyclable.

Future fixes?

Aebi points towards new technology that has been developed by Professor Ray Frost from the Queensland University of Technology. This ''super sponge'' mat looks like a pillow and is made from a material based on an expanding clay layer which has been modified. It is held between polyethylene sheets.

&quotThe product is only now in the commercialisation stage and it will be interesting to see how it goes in the highly competitive and price-sensitive absorbent market," Aebi says.

&quotTo date, the newest absorbent technologies remain organic-based materials as they are the most cost-effective and efficient absorbents on the market when you take all factors into account (including sustainability)."

The new product works through a chemical reaction occurring between the sponge and the oil. The oil can then be squeezed out, recycled and used again.

Frost says there is an urgent need to control accidental and deliberate releases of oil on both land and water.

&quotOil spills cause severe adverse impacts to our ecosystems and have a long-term effect on the environment," he said.

&quotThere is a huge cost involved in cleaning up oil spills with the Queensland Department of Main Roads alone spending about $25 million a year mopping up accident oil spills."

Despite the large number of land-based spills that make their way into Australian waterways each year, the response to such spills is still poorly regulated.

Fortunately, spill response materials have advanced to become ''greener'' over the years and will continue to do so with the ongoing development of new technology. Industry commentators report that the initial uptake of these environmentally friendly options was slow, but have now become the preferred choice in spill control.