Ever come across an overflowing spill tray full of oily water? Or noticed a rainbow sheen around your supposedly '100% effective' spill mats? Using the wrong products for the job won't stop pollution and won't protect you from fines.

Spill pads, mats, nappies and trays are a category of products designed to capture oil leaks and fuel spills from motor-driven tools, machinery and plant. When resting or in operation, old equipment can leak oil, and spillages can occur when topping up oil or refuelling.

Under pollution prevention legislation, failure to implement effective spill control measures can lead to site closure, prosecution and fines, not to mention reputational loss from negative headlines. (See Know the Law: Spill Prevention & Dewatering.)

So which are the best spill containment products for indoor and outdoor use?

Products designed to capture leaks and spills can be split into three categories:

• Spill trays
• Absorbent mats, pads and nappies
• Smart polymer spill pads

Spill Trays

Spill trays are simple steel or plastic bunds used for collecting and containing leaked or spilt contaminants. Low-cost and highly reusable, they are very popular for indoor use. Trays are best for collecting free-flowing liquid, for example when draining an oil sump. For oil drips, a tray might be overkill and an oil absorbent pad could be considered.

Spill trays should not be used outdoors as rainfall may cause them to overflow – releasing pollutants into the environment.

Absorbent Spill Mats, Pads and Nappies

Polypropylene-based absorbents are the active material in the majority of spill containment products and spill kits on the market today.

Although commonly used outdoors, polypropylene absorbents do not retain pollutants permanently. Polypropylene is a sponge-like material; liquid can go in but it can also come out again.

This is most evident when it rains. If polypropylene gets saturated, the absorbed pollutants can float out on top of the excess water. A rainbow sheen around these products after rainfall is a tell-tail sign.

To get around this, some products have sidewalls but, oddly, these usually contain the same absorbent material as the base –so contaminants can still leak out as the product fills with water.

Any contaminated water contained inside must be disposed of in hazardous waste bins, increasing your waste disposal costs. And products with sidewalls can be difficult to move when full without spilling water over the sides. The temptation for operatives is to tip the contaminated water onto the ground.

It’s not advisable to carry or store these products in an upright position as contaminants are likely to drain out. Jet washing, too, will flush contaminants out.

Absorbent-based pads, mats and nappies can be used until their quoted oil retention capacity is reached although for reasons explained above this is a somewhat redundant concept.

Smart Polymer Spill Pads

Smart polymer spill pads use an innovative process to solidify oil, fuel and other hydrocarbons inside the pad – neutralising the pollutants.

Green Rhino’s EnviroPad^® is the market-leading smart polymer spill pad and the only one designed for outdoor use. Its proprietary smart polymer reacts with hydrocarbons forming a solid and insoluble rubber-like substance.

The solidified pollutants are trapped inside the pad and physically cannot leak out. Rainwater isn’t contaminated by the solidified pollutants, so excess water can be allowed to drain out before storage or disposal. 

EnviroPad^® is available in a range of sizes including models large and robust enough for mini-diggers and JCBs to be parked on top.

A unique feature of EnviroPad is that it has operating and disposal instructions printed on it, ensuring that operatives know how to use the pads correctly and can determine when they need replacing.

Smart polymer spill pads can be reused until their oil retention capacity has been reached.

Verdict

For indoor use (e.g. vehicle depots and maintenance workshops), a metal or plastic spill tray is a cheap and effective solution, especially for collecting free-flowing liquid. For drips and small spills, a spill pad may be considered.

For outside use, spill trays and absorbent-based pads, mats and nappies are prone to leaking and overflowing in wet weather, which will incur clean-up costs if site staff are diligent; pollution if they are not. It also means that, after every heavy rainstorm, there can be litres of contaminated water pooled inside these products which will need to be disposed of in hazardous waste bins – increasing your waste disposal costs and, ultimately, the lifetime cost of the product.

The best spill containment option for outdoor use is the EnviroPad^® smart polymer spill pad. It doesn’t leak, doesn’t create waste water for disposal and – surprisingly – costs less than the market-leading absorbent-based products.

You may also find these articles helpful:

• Best Practice Guide to Dewatering Excavations
• 3 Ways to Generate Less Contaminated Water on Construction Sites
• Best Way to Dewater New Transformer Bunds
• Know the Law: Spill Prevention & Dewatering