Taking Absorbents into the 21st Century

Polypropylene and polyester absorbents offer several advantages over messy, labor-intensive, first-generation absorbents.

• By Reuben Weinstein
• Jul 01, 2003

AS many safety managers know, absorbents have long been the first line of defense when dealing with a chemical or oil spill in the workplace. While the Environmental Protection Agency has no management guidelines for the use of specific absorbent materials, safety managers have an obligation to protect their employees from these types of hazards and to protect their companies from the liability that could arise from a spill.

Like many products on the cutting edge of technology, first-generation absorbents had some weaknesses. They were messy and labor-intensive. Surprisingly, many of these products are still prevalent today. One of the first absorbents, and still widely used, is clay-based kitty litter. Kitty litter is inexpensive, but it has a low absorption ratio (volume applied vs. volume absorbed).

Clay-based products primarily absorb liquids on the outside surface of the clay particle. There is no internal structure that allows for true "absorption." The larger particle size causes the product to sit on top of peaks contained in concrete and other uneven, porous surfaces. This prohibits the material from getting down into the pores and valleys and absorbing these trapped liquids.

It requires more than 15 pounds of kitty litter to pick up one quart of 10w40 motor oil. In addition, kitty litter is not biodegradable, and therefore dumping large quantities will not only take up valuable landfill space, but can also get very costly. With increasingly stringent budgetary and environmental guidelines, managers must consider the labor and fees associated with proper disposal when making absorbent purchasing decisions.

Evolution of Absobent Products
About 15 years ago, absorbent manufacturers began incorporating cloth, paper, and fabric to make their products more effective. Paper cellulose was initially used, but manufacturers quickly shifted to incorporating polypropylene, one of the key ingredients used in disposable diapers. While this batting served its purpose to better absorb spills, it fell apart easily, making cleanup and disposal a project unto itself. The development of better absorbents further evolved into creating pad forms, or booms. These booms were stuffed with anything from nylon to paper towels to help keep them afloat in water.

Further, the development of melt-blown absorbents served the industry fairly well for many years. They have the ability to absorb 25 times their own weight, are hydrophobic, and effectively clean spills on both land and water. They also have been known to lose their strength and tear under certain working conditions.

It is important to consider the ability of an absorbent to hold up in various conditions. For example, some melt-blown absorbents will shred and blow into machinery or engines, causing further damage. In most cases, melt-blown absorbents need to be disposed of after initial contact with a contaminant. The tensile strength and reusability of melt-blown absorbents have caused many in the industry to re-evaluate their cost effectiveness in an already fiscally strapped time.

The New Breed
In the past five years, a new breed of absorbent has been developed to resolve the strength, reusability, disposability, and economic issues associated with traditional absorbents. Incorporating the latest innovations in textile production, manufacturers have created fiber-locked and needle-punched polypropylene absorbents, which have been used successfully in pads, pillows, booms, and rolls. These absorbents are:

• Reusable--highly reusable and can be wrung out and washed hundreds of times.
• Durable--manufactured to be non-tearing and non-shredding. This type of textile construction guarantees increased durability for tough operations.
• High in absorbency--Fiber-locking and needle-punching polypropylene are able to absorb significantly more oil than traditional absorbents. They are the only absorbents that can absorb No. 6 (Bunker C) oil.
• Faster--increases the rate at which the material can absorb oils and other hazardous substances. This improved absorption rate can minimize environmental damage.
• Economical--reusable, allowing managers to spend less on materials supply.

Polyester's Advantages
Absorbents that use polyester are another advancement that will respond to user needs. Polyester makes a good alternative to polypropylene because it is resistant to most acids. Polyester also has a strong resistance to weak alkalis and a moderate resistance to strong alkalis are room temperature. In addition, polyester's melting point of about 460 degrees Fahrenheit makes it an ideal absorbent material for hazardous spills in high-temperature environments. Because it incorporates polyester's textile structure with strong, reusable fiber-locked and needle-punched construction, the resulting absorbent is both functional and cost effective.

Like many of the industries they serve, absorbent manufacturers have come a long way in developing stronger, safer absorbents that are both highly functional and cost effective. The absorbent industry will continue to expand and to evolve as new design techniques arise and user demand intensifies.

This article originally appeared in the July 2003 issue of Occupational Health & Safety.