Safe Lead Abatement at a Major Food Processing Plant

The dangers of lead in food handling or processing plants is of special concern, considering that the most common form of lead poisoning is through ingestion. The negative health affects of lead exposure are cumulative and can, at high exposure levels, lead to coma, convulsions, and death. Lead affects children the most severely, impairing development of the brain and nervous systems. The Centers for Disease Control and Prevention (CDC) estimates that nearly 9 percent of American children under the age of six are at risk with blood lead levels above the threshold of 10 micrograms/dL, making lead exposure the most pressing national environmental health concern for children. As a result, implementation of proactive measures of protection against lead is being undertaken by some of the larger food processors.

The project scope included the cleaning of approximately 1,100 square feet of surface area on steel I-beams located in the confection ingredient processing rooms of the plant. Each room housed four large processing vats which occupied most of the available space. The goal was to remove the coatings while maintaining environmental cleanliness and achieving a surface profile suitable for application of the new epoxy-based protective coating. The specifications called for a finish comparable to a Steel Structures Painting Council SP 6, Commercial Blast Cleaning, described as a surface "free of all visible oil, grease, dirt, dust, mill scale, rust, paint, oxides, corrosion products, and other foreign matter..."

Some sensitive areas containing lead-based paint presented challenges that are particular to food processing plants: tight and hard-to-access spaces, conduits and steam pipe congestion, and heat-induced hardening of aged paint. Early attempts to remove the lead-based primer on some of the I-beams proved too difficult using chemical stripping methods. The chemical removal process also resulted in unpredictable schedules that could not support narrow shutdown windows, and the imprecise nature of chemical application cross-contaminated nearby production equipment.

Pittsburgh-based CRX Environmental Services provided turnkey lead abatement services, labor, and materials to remove the hazardous coatings. CRX Environmental's crew mobilized during a hectic Christmas holiday shutdown: 19 other contractors were involved in various maintenance and construction activities during the outage to prepare the plant for the new year. CRX ran a sample area with Pentek's shrouded power tools as a reference standard for the surface finish and, upon approval, work on the beams commenced.

Preparations were straightforward. A plastic drop cloth was stretched across the vat beds, drains, pumps, and motors as a precaution against the chance that heavier, non-respirable particulates could accidentally escape the strong pull of the vacuum system. Ladders were used along with planks to access the 12 ft. high beams. These accessories comprised the sum of CRX's work area preparation; no elaborate containment structures were required, nor were expensive ventilation schemes.

A Pentek VAC-PAC self-drumming HEPA vacuum unit, capable of running 10 shrouded power tools over 200 ft. away was stationed outside the rooms. Pentek's shrouded power tools include ROTO-PEEN Scalers to remove coatings in broad swaths and CORNER-CUTTER needle guns to access corners, edges, and around rivets. CRX personnel attacked the beams with these tools from various positions around and over the vats, each connected by a length of hose that conveyed all removed coatings directly into the VAC-PAC's onboard, DOT approved, 55-gallon waste disposal drum.

The ROTO-PEEN Scaler and CORNER-CUTTER needle gun work in complementary fashion: the former for flat areas and the latter, with the help of a battery of specially conformed shrouds, for hard-to-reach corners and edges . Each individual operator could quickly change his tool by transferring the vacuum hose and air line to the new tool. The hose lengths were taped off at strategic positions so that workers lifted only the tool itself, not the weight of the hose. This ability to rapidly change out the light-weight tools or adjust the geometry of the CORNER-CUTTERs' shrouds meant that workers could efficiently abate all the surfaces within their reach--flanges, tight interior webbing, rivets and bolts--providing flexibility unavailable with other methods.

Using this integrated approach, CRX workers were able to delead extremely tight surfaces like the inside top flanges, inside webbing, and inside bottom flanges of I-beams that were close to the walls. A Right-Angled ROTO-PEEN Scaler, with a specially-configured motor drive, was utilized for increased productivity on the interior webbing of the beams. The VAC-PAC, conveniently parked outside the work area, served as a powerful, central conveyor and safe depository for all the accumulated waste material.

With respect to worker safety and hygiene, CRX personnel wore respirators only until such time airborne monitoring and personal sampling verified the cleanliness of the Pentek system; readings were often below detection limits, and none were above 7 micrograms per cubed meter. These were well below regulatory standards which limit lead concentrations for each worker at a Personal Exposure Limit of 50 micrograms per cubed meter and allowed continued operations without the use of respiratory protection. Post-job worker blood tests revealed negligible changes in lead blood concentration. Due to the cleanliness of the Pentek abatement process, and buttressed by ample historical performance data, CRX Environmental does not normally require their crew to wear respirators when using the Pentek system. "The residual risk has been reduced through Pentek's engineering to near zero airborne discharges," said John Sotiriou, CRX's project manager.

"The [Pentek] process is wonderful, and the beams look great," said the facility's project engineer, pleased that there would be time to repaint and refill the vats before the outage was over. "With so many different operations going on at the same time, the contractor's lead removal activities were the least of my worries."