classroom contamination from lead bearing ceramic art glaze … · 2018. 1. 31. · ceramic art...

of 28

Classroom Contamination from Lead Bearing Ceramic Art Glaze

William R. Rath

Industrial health & Safety Consultants, Inc.

Woodbridge, CT

Woodhall Stopford, MD, MPH

Duke University Medical Center

Durham, NC

of 28

Abstract

On April 4, 2006, the Connecticut Department of Public Health (DPH) issued a Product

Advisory and Information Sheet regarding the “Use of Leaded Ceramic Glazes in School Art

Classes.” This sheet advised Connecticut school districts to determine if leaded ceramic art

glazes had been used in the district and, if so, to coordinate with the local health departments to

identify and remedy any lead hazards that may have been created by such use.

This paper follows the response of two Connecticut school districts from the time the

advisory was issued until the affected art rooms were reoccupied. It examines the regulatory,

technical, scientific, and emotional aspects of the process, and includes the following topics:

Chemistry and toxicology of ceramic art glazes

Health concerns from the use of leaded art glazes

DPH guidance (risk assessment & clearance standards)

School issues (Cost factors, scheduling, loss of use, emotional issues)

Local health department issues

Survey techniques, results, and trends

Lead abatement plans

Decontamination processes and techniques

Waste management

Lead in “lead free” art glaze

Potential for lead contamination and exposure from “lead free” art glaze

Kiln and kiln accessory contamination considerations

ASTM guidelines for safe use of art products

of 28

The paper concludes with a discussion of the appropriateness of applying childhood lead

poisoning standards to art rooms for older children, and a call for more research to clarify the

following issues:

How much lead contamination will result from the use of “lead-free” ceramic art

glazes?

What surface contamination standards are appropriate for older children and

adults?

of 28

Introduction

On April 4, 2006, the Connecticut Department of Public Health (DPH) issued a Product

Advisory and Information Sheet regarding the “Use of Leaded Ceramic Glazes in School Art

Classes.” This sheet advised Connecticut school districts to determine if leaded ceramic art

glazes had been used in the district and, if so, to coordinate with the local health departments to

identify and remedy any lead hazards that may have been created by such use. The advisory

specified the EPA lead dust hazard level of forty micrograms of lead dust per square foot of

surface area (40 ug/ft2) as the trigger value to initiate decontamination activities and as the

clearance standard to determine the efficacy of decontamination activities. William R. Rath of

Industrial Health & Safety Consultants, Inc. assisted two Connecticut school systems with their

response to this advisory. Thirteen buildings were evaluated for lead dust contamination,

including two high schools, four middle schools, six elementary schools, and a multi-use

building that included space used for art instruction. Lead dust contamination levels in excess of

the EPA hazard level were identified in all 18 art rooms within the 13 buildings. This paper will

describe the response of these two school districts from the time the advisory was issued until the

affected art rooms were reoccupied.

Art Room Lead Contamination Issues

Lead in Ceramic Art Glazes

Ceramic art glazes are used to strengthen and decorate art formed from clay. Modern

ceramic art glazes are pre-mixed liquids that contain frit made from finely ground glass. When

the glaze is fired in a high-temperature oven called a kiln, the glaze vitrifies into a permanent,

impermeable coating over the clay. Various other materials, including lead, are added to the

of 28

glass frit to improve the performance of the glaze during the firing process or to enhance the

color of the finished product. According to Material Safety Data Sheets provide by ceramic

glaze manufactures, ceramic frit represents approximately fifty percent of the weight of liquid

glazes (American Art Clay Company, Inc., 2005) and, depending upon the formulation, up to 28

percent of that frit can be lead oxide (Duncan Enterprises, 2005).

Leaded glazes can be found in several settings. They are used commercially for making

dinnerware, both for decorating and for creating an impervious, clear surface using a dipping

glaze. The hobby ceramic industry developed based on the use of pre-mixed liquid glazes, many

containing lead frits. Individuals would decorate greenware with lead-based glazes in controlled,

commercial ceramic studios. During the last decade contemporary ceramic studios have, for the

most part, replaced hobby ceramic studios. Contemporary ceramic studios are commercial

ventures where individuals decorate fired bisqueware with lead-free glazes. The decorated ware

is then dipped in a glaze and fired by studio workers. Most of the dipping glazes used in these

establishments are lead-based.

The use of ceramic art glazes in schools varies according to the age and expertise of the

students. In primary school art classes, student involvement usually consists of decorating

bisqueware that is fired by the teacher. In middle and high schools, art students become involved

in the firing process as well, and advanced art students may apply and fire dipping glazes as well

as decorative glazes.

Lead-related health concerns in ceramic studios

Lead exposure can result in both acute effects, including acute mental changes

(encephalopathy) as well as chronic effects such as difficulty with school work, poor attention,

anemia, kidney effects and motor and sensory nerve damage. In one studio of both professional

of 28

ceramic decorators and hobby ceramicists using leaded glazes, blood lead levels in both groups

were no different from un-exposed controls and there were no findings of anemia in either group

(Stopford, 1988). In commercial studios working with leaded dipping glazes, blood lead levels

can range as high as 50 µg/dL. In some operations, such glaze making (not a component of

contemporary ceramic studios or hobby ceramic studios), blood levels have been found to be as

.high as 84 µg/dL. The maximum acceptable blood lead level in the workplace is 30 µg/dL

(ACGIH, 2001). In children, however, central nervous system and kidney effects can occur at

lower levels of exposure than in adults (Goldwater, et al, 1988).

During the glazing process, lead from the liquid glaze can contaminate surrounding

surfaces in several ways. The most direct means of contamination is spillage of the liquid glaze

product. When allowed to air dry, the dried glaze is easily crumbled into a fine, talc-like dust

that readily spreads throughout the surrounding area.

Studies have been completed of the extent of lead contamination in contemporary

ceramic studios. Stopford and Stanion (1998) found lead contamination of surfaces in such

studios ranged from 33 to 793,000 µg/ft2 while contamination levels in customer areas ranged

from non-detectable to 2295 µg/ft2. The investigation described in this paper identified

contamination levels in public school art classrooms from below detection limits to 68,000

µg/ft2.

Lead in ceramic art glaze can also volatilize during the firing process, contaminating the

inside of the kiln, other objects within the kiln, and, potentially, adjacent work areas. All modern

kilns, however, are ventilated preventing contamination of the studio with lead fumes from the

firing process. Prior to mandatory kiln ventilation, studio exposure levels from firing leaded

of 28

glazes could reach as high as 17 µg lead/m3 in unventilated studios. With use of dilutional

ventilation, exposures were found to be

of 28

Stop using and properly dispose of lead-bearing ceramic art glazes

Notify the local health department

Determine the extent of contamination

Develop a site-specific clean-up plan

Notify parents that ceramic art projects may be contaminated with lead

Henceforth, stock and use only “non-hazardous” ceramic art glaze bearing the

“AP” seal of the Art and Creative Materials Institute.

The advisory specified the EPA lead dust hazard level of 40 ug/ft2 as the trigger value to

initiate decontamination activities and as the clearance standard to determine the efficacy of

decontamination activities. Lead dust contamination levels in excess of 40 ug/ft2 were identified

in every art room in the two school systems described in this paper.

Local Health Department Issues

The April 4 advisory recommended that schools contact their Local Health Department

(LHD) for guidance on dealing with potential contamination issues. The two school districts

described in this paper spanned political areas that included four local health departments. Three

of the four health directors were physicians. The fourth director was a public health professional

that was not a physician.

As suggested in the DPH advisory, all of the health directors advised the school systems

to engage a licensed “Lead Inspector Risk Assessor” (LIRA) to identify the extent of the lead

contamination. After the initial surveys were complete, meetings were held to discuss sample

results and remediation options. The LIRA then developed site-specific decontamination plans

that were approved by the health directors. None of the health directors recommended blood

lead screening for the teachers or students.

of 28

The LIRA briefed the health directors periodically as the decontamination work

progressed, and contacted them for guidance in situations that were not covered by the

decontamination plans. The LIRA reviewed the final clearance sample results with the health

directors before opening the rooms for unrestricted access. One of the health directors stipulated

a final pre-occupancy inspection by a member of the health department staff that was a certified

lead inspector.

School Issues

Loss of Use

The April 4 advisory recommended that schools “. . . stop use of and restrict access to all

areas where ceramic/pottery operations were conducted in conjunction with leaded glazes,

including glaze storage areas, kilns, and ventilation systems, until further evaluation is

conducted.” Based upon this recommendation, most school systems simply stopped using the

affected art rooms until they could be tested for lead contamination. As noted earlier, lead

contamination levels in excess of 40 ug/ft2 were identified in every art room tested during this

study, so the 18 art rooms were not available for use from the time the advisory was issued until

the decontamination activities were complete. This period of restricted access ranged from

slightly less than a month to well into the summer break.

The loss of art room use affected different schools in different manners. Generally

speaking, elementary schools were the least affected, as the art teachers were able to deliver art

programs from carts that could be wheeled room to room. At the other extreme were the high

school art rooms, some of which were being used by students that were completing their

portfolios for admission into art colleges.

of 28

Both of the school systems considered in this paper elected to focus their first efforts on

the high school art rooms, followed by the middle and elementary schools. For budgetary

reasons, one system deferred the decontamination work in one elementary school and one a

middle school until after the July 1 start of the new fiscal year.

Emotional Factors

The decontamination process is described in detail later in this paper, but the basic

operating principle was to decontaminate items that could readily be decontaminated, and to

discard those that could not. This guideline was easily applied to some items, such as an

expensive stainless steel table that was easy to clean or a cheap pair of pom-poms that might

never be successfully decontaminated. It was more difficult to apply to other items that could be

decontaminated, but only at a cost that exceeded the value of the item. At a fully burdened labor

rate of $75 per hour, it was simply more cost-effective to discard many items rather than to

attempt decontamination and subsequent representative clearance wipe sampling.

The art teachers encountered during this project were dedicated, highly creative

professionals that were both intellectually and emotionally involved with their work. All had

spent many years supplementing the materials available through normal procurement methods

with supplies, props, and accessories that were bought at yard sales, cajoled from local

merchants, and salvaged from the recycle bin. It is likely that as much as half of the creative

materials encountered during this project were personally procured by the art teachers at their

own time and expense.

The presence of these additional creative materials created an interesting situation. It was

not in the best interest of the school system to decontaminate items that were cheaper to replace

than decontaminate. However, many of the items to be discarded were not purchased by, and

of 28

presumably would not be replaced by, the school system. To address this situation and the

apparently competing interests of the school system and the art teachers, it was necessary to

formalize the means by which the clean/discard decision was made.

The first step in this process was to work with art department personnel to educate the

consultant and the abatement contractor foreman on the value of items found in the art room.

Objets d’art were presumed to be worth decontaminating unless extraordinary efforts were

required. Art supply catalogs were provided so that the cost of decontaminating ordinary art

equipment and supplies could be compared to replacement costs. The use of props and models

were described so that an old boot used for sketching exercises would not be discarded without

due consideration of their intangible value.

The clean/discard decision for any given item could be made at any one of three

progressive levels. The abatement contractor foreman made the vast majority of clean/discard

decisions as the work progressed. Questionable items were referred to the consultant. Items that

could not be readily classified by the consultant were placed in clear plastic bags and set aside

for evaluation by the art teacher.

All of the art teachers understood the necessity of making the clean/discard decisions, and

most of the questionable materials set aside by the consultant were ultimately discarded. But

none of the art teachers could ignore the years of effort required to amass their inventory of

creative materials, and there were times when making these decisions evoked strong emotions.

Direct Cost

The direct cost of decontaminating all eighteen art rooms, which includes the cost of the

industrial hygiene consultant, analytical laboratory, abatement contractor, and hazardous waste

disposal, was $199,134, or an average cost of approximately $11,063 per room. Indirect costs

of 28

are difficult to quantify, partly because not all of the discarded items were immediately replaced,

and partly because many of the discarded items had been personally accumulated by the art

teachers outside of normal procurement channels.

Survey Techniques, Results, and Trends

Lead Wipe Samples

Lead wipe samples were collected in accordance with ASTM E1728, “Standard Practice

for Field Collection of Settled Dust Samples Using Wipe Sampling Methods for Lead

Determination by Atomic Spectrometry Techniques.” Samples were collected on ASTM E1792

compliant Environmental Express “Ghost Wipe“ lead wipes. Wipe samples were analyzed by

flame atomic absorption spectroscopy, EPA Method SW846 (7420), by laboratories accredited

under the Environmental Lead Laboratory Accreditation Program (ELLAP).

The goal of wipe sampling was to determine the extent to which the art rooms were

contaminated. If portions of an art room could be clearly identified as not contaminated, then it

would not be necessary to decontaminate the entire room. Accordingly, more wipe samples were

collected during the initial investigation of the art rooms than would typically be collected during

a lead paint hazard assessment or post-abatement clearance. Depending upon the size and use of

the room, as few as five or as many as 26 samples were collected in each art room, with an

average count of 19 wipe samples per room (includes blanks).

Wipe samples were collected in the following locations

Floors

Horizontal working surfaces (tables, desks, counters, etc.)

Storage shelves & cabinets

Elevated horizontal surfaces (tops of wall cabinets, bookcases, etc)

of 28

Kilns & Associated Exhaust Hoods

Ventilation Systems

This sampling strategy generated enough data to allow portions of 14 of the 18 art rooms

to be excluded from the decontamination process. Examples of sample data collected from a

high school, a middle school, and an elementary school are included in Attachments 2, 3, and 4,

respectively.

Results and Trends

Liquid Glaze Storage Areas The highest levels of contamination were identified on

horizontal surfaces in liquid glaze storage areas. Not surprisingly, storage areas with visible

accumulations of dried glaze returned higher results, with the highest storage area returning

results of 68,000 ug/ft2.

LEAD CONTAMINATION IN GLAZE STORAGE AREAS (16 ART ROOMS)

Contamination Level Number of Areas

Less Than 40 ug/ft2 1

40 ug/ft2 to 500 ug/ft2 6

500 ug/ft2 to 1,000 ug/ft2 1

1,000 ug/ft2 to 10,000 ug/ft2 6

10,000 ug/ft2 to 68,000 ug/ft2 2

Contamination in glaze storage areas proved to be remarkably persistent. One middle

school art room evaluated during this study had been occupied by the same teacher for over

fifteen years. This teacher had stopped using the ceramic arts kiln shortly after she moved into

the room because the dust from the kiln aggravated her allergies. Modeling clay and paint were

substituted for ceramic clay and glaze, and the kiln-fired ceramic art materials were discarded.

Over the years this room had been partially remodeled, with new paint and floor covering, but

of 28

the original wall cabinets remained in place. The only sample in this room to return results

greater than 40 ug/ft2 was collected in one of these cabinets at a location where ceramic art gazes

would likely have been stored. The contamination level in this cabinet was 2,500 ug/ft2.

A similar situation was observed at a nearby elementary school. The art teacher at that

school had moved in five years earlier and discarded all materials that were either hazardous or

in unmarked containers. Two years after that the entire room was remodeled except for the

inside of the storage closets. A wipe sample collected from the glaze storage shelf, which at the

time contained only lead-free glazes, returned results of 1,300 ug/ft2. All other surfaces in that

room returned result near or below the 10 ug/ft2 detection limit.

It also appears that contamination builds up quickly in glaze storage areas. Three of the

art rooms evaluated during this study were in a new elementary school that was placed in service

only eight months earlier. The glaze storage cabinets in these rooms returned wipe sample

results of 20, 59, and 370 ug/ft2.

Art Storage Areas After the glaze storage areas, the areas with the most contamination

were locations where ceramic art work was dried, cooled and stored while work was in progress.

Many of these were purpose-built drying cabinets, with difficult to clean mesh sides and

tempered pegboard shelves designed to enhance airflow around the artwork. Contamination in

these areas ranged from below the 10 ug/ft2 detection limit on open storage shelves in a new (less

than one year old) art room to 4,900 ug/ft2 in an older drying/cooling cabinet in a high school art

room.

LEAD CONTAMINATION IN DEDICATED CERAMIC ART

COOLING AND TEMPORARY STORAGE AREAS (12 ART ROOMS)

Contamination Level Number of Areas

Less Than 40 ug/ft2 2


of 28

100 ug/ft2 to 500 ug/ft2 9

500 ug/ft2 to 1,000 ug/ft2 2

1,000 ug/ft2 to 4,900 ug/ft2 3

Kilns Results from wipe samples collected from within the kilns were inconsistent. Part

of this inconsistency can be attributed to the nature of the refractory materials used within the

kiln, which present a difficult surface from which to collect wipe samples. Another part of this

inconsistency was the sampling sites selected by the inspector. Samples within the kilns were

initially collected from the horizontal surface on the bottom of the kilns, which the inspector

assumed to be the most likely surface to be contaminated. This assumption turned out to be

incorrect because ceramic art is placed on a series of moveable shelves that are stacked vertically

within the kiln, so any glaze shed by the artwork falls upon the shelves rather than the floor of

the kiln. Based upon this information, the inspector started collecting samples from the inside

walls of the kilns to detect lead that may have volatilized and contaminated the kiln walls.

The results of the samples collected from the kiln walls were more consistent from kiln to

kiln, and were generally higher than those collected from the floors of the kilns. The floors of

three kilns returned results below detection limits and one very old kiln returned a floor

contamination result of a 450 ug/ft2, with four other kilns returning an average floor

contamination level of approximately 45 ug/ft2. The average contamination level detected on the

walls of six other kilns was approximately 76 ug/ft2, with results ranging from 16 to 120 ug/ft2.

Contamination levels on the exterior top surfaces of kilns varied in direct proportion to

the age of the kilns. These levels ranged from a low of 10 ug/ft2 on a kiln that was less than two

years old a high of 3,100 ug/ft2 on a kiln that had been in use for more than 25 years.

The newer kilns were equipped with direct ventilation systems that transport air directly

from the kiln to an exhaust location outside of the building. Most of the older kilns were located

of 28

under ventilation hoods. One kiln considered during this study was located in a boiler room and

was provided with no specific ventilation equipment.

The inside potions of direct ventilation systems are not normally accessible to building

occupants and were not considered during this survey. Samples collected from the underside of

the exhaust hoods returned results from below detection limits to 1000 ug/ft2, with no apparent

trend related to the age or use of the kilns. It is possible that variations in custodial practices

caused the variations in contamination levels.

Working Surfaces

Working Surfaces Working surfaces included desks, tables, and counter tops.

Contamination on these surfaces was directly related to the location of the surface and the

activities that took place on the surface. The highest contamination levels were found on

working surfaces adjacent to glaze storage areas, typically countertops on base cabinets located

under glaze storage wall cabinets. Elevated levels were also observed on working tables where

glazes were applied, but at lower levels than might be expected, presumably because these

surfaces are routinely cleaned. However, most of the working surfaces in the classrooms were

well below 40 ug/ft2, also a likely result of routine cleaning activities.

LEAD CONTAMINATION ON WORKING SURFACES (18 ART ROOMS)

Contamination Level Number of Surfaces

Less than 10 ug/ft2 26



100 ug/ft2 to 500 ug/ft2 6

500 ug/ft2 to 1,000 ug/ft2 1

1,000 ug/ft2 to 3,200 ug/ft2 3

of 28

Floors Floor contamination also varied by location. The highest contamination levels

were found on floors adjacent to glaze storage areas, with one area in front of open glaze storage

shelves returning results of 18,000 ug/ft2. The next highest levels of contamination were

identified on floors adjacent to kilns, the highest of which returned results of 450 ug/ft2.

Floor contamination in other areas of elementary and middle school art rooms was below

40 ug/ft2. However, both of the ceramic-intensive high school art rooms considered during this

study had prevailing floor contamination levels above 40 ug/ft2.

LEAD CONTAMINATION ON FLOORS (18 ART ROOMS)

Contamination Level Number of Locations

Less than 10 ug/ft2 37


40 ug/ft2 to 100 ug/ft2 15

100 ug/ft2 to 500 ug/ft2 8

500 ug/ft2 to 1,000 ug/ft2 1

1,000 ug/ft2 to 18,000 ug/ft2 2

Ventilation Systems Most of the rooms evaluated during this study were equipped with

unit ventilators. The two high schools were equipped with centralized air handling systems.

Both types of systems were approached in the same manner - return air components were tested

for lead contamination and further investigation was conducted only if these components were

contaminated in excess of 40 ug/ft2. None of the unit ventilators indicated return air component

contamination in excess of 40 ug/ft2, but one of the high school return air ducts did.

All of the high school art rooms considered during this study had been completely

renovated within the previous three years. Two of the renovated art rooms had been equipped

with completely new HVAC systems. The third room was upgraded with new distribution

equipment that was tied into the existing circa 1970 HVAC system. Wipe samples collected

within the old HVAC trunks leading to and from the art room indicated lead contamination

of 28

levels from 230 to 5,200 ug/ft2 in the return air system and 310 to 910 ug/ft2 in the supply air

system.

There were no records or other indication that these ducts have been cleaned since they

were installed in 1970. The dirt in these ducts is a sticky black substance that is adhered to the

inside surfaces of the ducts. It is quite possible that the lead dust trapped within this dirt could

remain there indefinitely until disturbed by some outside force. Nevertheless, the air handling

system serving this art room and adjacent rooms in the fine arts wing was shut down as a

precautionary measure until the ducts can be properly decontaminated.

Testing of local exhaust ventilation systems was limited to portions of the systems, such

as intake grills, that could be contacted by the occupants. Contamination inside of the local

exhaust systems was not an issue because dust from these systems is unlikely to work its way

back into occupied portions of the room.

Elevated Surfaces Elevated surfaces were sampled to provide insight into the extent of

the art room contamination. Surfaces such as the tops of storage cabinets, light fixtures, and

bookcases are generally not included in routine cleaning, and can add a historical perspective to

the sample results. Contamination in these elevated, out of the way areas suggests a history of

widespread contamination and a need for a wall-to-wall, top-to-bottom decontamination.

In most cases, contamination levels on elevated surfaces reflected contamination levels

elsewhere in the room, that is, rooms with generally high levels of contamination on floors,

working surfaces, and storage areas had high levels of contamination on elevated surfaces, and

vice-versa. The high school art rooms with intensive ceramic art programs returned elevated

surface contamination results from 61 to 370 ug/ft2. A middle school art room with a 25 year

history of ceramic arts work returned an elevated surface contamination result of 92 ug/ft2.

of 28

Roll-Around Carts Roll-around carts were identified in four elementary school art

rooms. Wipe samples collected from the shelves of these carts returned results of 96, 200, 880,

and 1,500 ug/ft2. These shelves had been used for temporary storage of in-progress ceramic art

work, and the contamination profiles were similar to those in the fixed ceramic art storage areas.

It is interesting to note that the cart that returned results of 880 ug/ft2 had been placed in service

only eight months earlier in a completely new elementary school.

Other Metals

The first art room considered during this study was evaluated before the Connecticut

DPH issued their advisory, so hazard evaluation protocols were developed to address all of the

potential hazards presented by ceramic art glaze contamination. The glaze of concern in this art

room contained both lead and cadmium, so both metals were included as analytes of interest in

the wipe samples. A level of 145 ug/ft2 was selected as the trigger level for cadmium

contamination, based upon the 1,560 ug/m2 “Health-Based Benchmark” proposed by the EPA’s

World Trade Center Contaminants of Potential Concern committee.

None of the wipe samples collected in this art room returned cadmium results in excess

of 145 ug/ft2. However, cadmium contamination tended to follow the trend of lead

contamination, with the areas of highest lead contamination having the highest cadmium

contamination. The sample data from this art room is shown in Attachment 4.

The DPH advisory did not consider contaminants other than lead, so response activities

initiated in response to that advisory were limited to issues of lead contamination. However, the

correlation that was observed between lead and cadmium contamination levels in this one

classroom suggests that decontamination activities suitable for reducing lead levels to below 40

ug/ft2 will also reduce cadmium contamination to levels well below the health-based benchmark.

of 28

Lead Abatement Plans

The Connecticut Childhood Lead Poisoning Prevention and Control regulations

implement abatement activities in child-occupied housing through lead abatement plans. These

plans are developed by a licensed “Lead Planner Project Designer” and are submitted to Local

Health Department (LHD) for review and approval.

The DPH advisory recommended a similar approach for the lead abatement plans

developed for art rooms. This approach expedited the planning and approval process by taking

advantage of the personnel and procedure infrastructure already in place for the childhood lead

poisoning program.

All of the abatement plans developed for this project identified the extent of the

decontamination work area and specified the following activities within that area:

Decontaminate all surfaces in the work area up to and including the top of the

highest horizontal surface in these areas.

Decontaminate all furnishings and other items within the work area

Dispose of items within the work area that cannot readily be decontaminated

Relocate decontaminated furnishings and other decontaminated items to

temporary storage provided by the Contractor

The plans also specified decontamination methods, clearance procedures, and waste

management requirements that are described in detail in the following section.

Abatement Techniques

Work Area Preparation

Because all items and surfaces within the defined abatement areas were presumed to be

contaminated with lead, preparing the abatement work areas was a simple matter of isolating

of 28

them from adjacent areas. Ventilation systems were shut down, and systems that did not require

cleaning were sealed with two layers of plastic sheeting. Openings to the work areas were sealed

with plastic sheeting and posted with lead warning signs. Access to the work areas was via a

two-chamber “change area” constructed and operated in accordance with OSHA regulations.

Decontamination Procedures

As described earlier in this paper, the basic operating principle was to decontaminate

items that could readily be decontaminated, and to discard those that could not. Items that could

not readily be decontaminated were packaged for disposal in clear, leak-tight, six-mil

polyethylene bags.

Most of the items decontaminated during these projects were non-porous items such as

chairs, jars, tools, and equipment. These items were cleaned using HEPA vacuums and wet

cleaning. Porous items deemed worth saving were cleaned using HEPA vacuums only.

A clearance standard of 40 ug/ft2 demands methodical decontamination and a constant

awareness of the potential for cross-contamination. The abatement contractors devised processes

by which contaminated items were moved progressively from the most contaminated areas to the

least contaminated areas as they were cleaned, with the final cleaning taking place in an area

immediately adjacent to the change area. Rags used for wet cleaning were not rinsed and re-

used, but were discarded after each clean surface of the rag had been used once.

One of the abatement supervisors used glass windows to train his crew on a three-step

decontamination process. A backlighted window was first cleaned with a rag soaked in a

trisodium phosphate solution to remove the grime, then rinsed with a rag soaked in clear water,

and then wiped dry with a dry rag. After demonstrating the effectiveness of this three-stage

process, the supervisor challenged the workers to achieve the same results using only two of the

of 28

three steps. By the end of the demonstration the workers were not only proficient in this three-

stage cleaning process, but were also convinced that this was the most expedient way to achieve

the “no visible dust, dirt, debris, or residue” standard for the final visual inspection.

Clearance Procedures

The lead abatement plan places the responsibility for the first visual inspection upon the

abatement supervisor. After decontaminated items passed the supervisor’s inspection, they were

placed on trays and moved through the change area to a well-lit inspection area immediately

adjacent to the change area. At this area the consultant inspected the decontaminated items to

make sure that they were free of visible dust, dirt, debris, and residue. Items that failed to meet

these criteria were returned to the work area for additional cleaning or set aside for further

evaluation of their value.

Representative post-abatement wipe samples were collected from items that met the

clearance criteria. Examples of post abatement wipe samples collected from articles

decontaminated and removed from a high school art room are included in Attachment 5.

Cleared items were placed in temporary storage pending laboratory analysis of the wipe

samples. Temporary “roll-off” closed-top storage containers were provided for this purpose at

most sites. Roll-off containers previously used to transport waste materials were lined with

plastic sheeting to avoid contamination of the items in storage.

Similar clearance procedures were applied to the inside of the abatement area. All

surfaces were inspected first by the abatement supervisor and then by the consultant to make sure

that they were free of visible dust, dirt, debris, and residue. The consultant then collected post-

abatement wipe samples in locations similar to those sampled during the pre-abatement

of 28

inspection. Examples of post abatement wipe samples collected from surfaces and equipment

within a high school art room are included in Attachment 6.

Waste Management

Waste Segregation

It was anticipated that the vast majority of the waste generated by the work would not

demonstrate the lead toxicity characteristic of “hazardous waste.” Accordingly, waste streams

were segregated as follows in order to minimize the volume of material that had to be discarded

as “hazardous waste”:

Lead-Bearing Ceramic Art Materials

Cleaning Rags, Protective Clothing, and Highly Contaminated Discarded Items

Lightly Contaminated Discarded Items

Waste Packaging

Lead-bearing ceramic art materials were packaged in leak-tight, metal 55-gallon drums

labeled in accordance with EPA and DEP regulations. Cleaning rags, protective clothing, and

highly contaminated discarded items were also packaged in this manner.

Lightly contaminated discarded items made up the vast majority of waste from these

projects. These items were packaged in clear, leak-tight, six-mil polyethylene bags labeled,

“DEBRIS FROM ART ROOM– ON HOLD PENDING LAB RESULTS.”

Packaged waste materials were placed in secure storage pending the results of waste

characterization samples.

Waste Characterization

Lead-bearing ceramic art material were identified as “hazardous waste” based upon

information available from product labels and material safety data sheets. These materials were

of 28

inventoried by product name and profiled as liquid waste containing lead, cadmium, copper,

cobalt, lithium and/or manganese. An example of ceramic art material waste inventory is shown

in Attachment 7.

Other materials in the waste stream were characterized by collecting representative

samples for analysis by the Toxicity Characteristic Leaching Procedure (TCLP). Of the 31

TCLP samples collected from barrels containing cleaning rags, protective clothing, and highly

contaminated items, only two returned results greater than the “hazardous waste” limit of 5.0

milligrams of lead per liter of leachate solution (5.0 mg/l). None of the 18 TCLP samples

collected from the “lightly contaminated” bagged waste returned results of 5.0 mg/l or greater.

Example TCLP sample data from a high school art room decontamination project is shown in

Attachment 8.

Waste materials returning TCLP results of less than 5.0 mg/l lead were released for

disposal as ordinary municipal waste. This lead to an interesting situation at several schools

where the art teachers asked if they could salvage discarded art materials that had “passed the

lead test.” Additional efforts were required to explain to the teachers and administration that

even though most of the waste from the decontamination work was not "hazardous waste" in

accordance with waste disposal regulations, it was nevertheless contaminated with small

amounts of lead and was not suitable for salvage.

Kiln and Kiln Accessory Considerations

Kiln Refractory Materials

The DPH advisory identified kilns as an area of concern, and recommended contacting

kiln manufacturers to determine how to clean refractory materials in kilns that had been used to

fire lead-bearing ceramic art glaze. Four kiln manufacturers were contacted for their cleaning

of 28

recommendations. None had refractory material cleaning recommendations per se, but two of

the manufacturers recommended prolonged maximum-temperature firing of the empty kiln under

conditions of maximum ventilation. Any lead remaining in the kiln after these conditions would

presumably be fused with the refractory materials and unlikely to re-emerge under normal

operating conditions. One of the kiln manufacturers recommended vacuuming after the high-

temperature firing.

Kiln Accessories

The capacity of the kilns is increased through the use of movable shelves stacked in

vertical layers. These shelves are stacked on square cross-section hollow legs called shelf

supports. Items to be fired are elevated from the shelves with a variety of stands, stilts, and

triskelion-shaped “triangles.” All of these accessories are fabricated from refractory materials,

and many are small and have complicated shapes. These features made kiln accessories difficult

to decontaminate, and, much to the chagrin of the art teachers, many of the smaller stands, stilts,

and triangles were simply discarded as a cost-effective alternative to decontamination.

Re-Contamination Considerations

Three ceramic art glaze manufacturers were contacted during the course of the art room

decontamination projects to determine what is meant by the term “lead free” when used to

describe ceramic art glazes. Several different answers were offered, but the only universally

agreed-upon answer was that "lead-free” means that the manufacturer does not intentionally

introduce lead into the glaze.

These intentions notwithstanding, testing by other parties (Stopford, unpublished data)

indicates that glazes marked as "lead-free" may contain up to 34.6 parts per million of lead. At

of 28

34.6 ppm lead, a 16 fluid ounce jar of glaze (which weighs about 800 grams) will contain about

0.028 grams, or 28,000 micrograms, of lead.

This lead in "lead-free" glaze can be problematic in two areas. First, dried glaze on the

outside of the glaze jars readily crumbles to powder and can easily cause local contamination

over 40 micrograms per square foot. Second, some of the available lead in the glaze will

volatilize during the firing process and may contaminate interior surfaces of the kiln.

The potential for lead contamination when using “lead free” glazes significantly changed

the expectations for the decontamination projects. The assumption that lead contamination

would cease to be a problem at the completion of the decontamination projects was now

questionable.

This change in expectations led to a change in kiln decontamination practices. There is

little point in discarding kilns and kiln accessories that cannot be decontaminated to less than 40

micrograms per square foot, only to have the contamination return a year later from using “lead

free” glazes. Instead, IH&SC developed a set of kiln use recommendations designed to

minimize lead contamination from ceramic art activities and to minimize the risk to occupants

from any lead contamination that may be inevitable. These recommendations are reproduced in

Attachment 9. Further recommendations for controlling exposures in a ceramic studio can be

found in the Safety Appendix to the American Society for Testing and Materials Standard

Practice C1023, Labeling Ceramic Art Materials for Chronic Adverse Health Hazards (ASTM,

2006)

of 28

Trigger Levels and Clearance Standards

The DPH advisory specified the EPA’s lead dust hazard level 40 ug/ft2 as the trigger

value to initiate decontamination activities and as the clearance standard to determine the

efficacy of decontamination activities. This hazard level was promulgated by the EPA in 2001

(EPA, 2001) as required by the Residential Lead-Based Paint Hazard Reduction Act of 1992, and

applies to all federal agencies that own residential property and all property owners that receive

assistance through federal housing programs. This hazard level has also been adopted by many

states, including Connecticut, as the standard for state childhood lead poisoning and prevention

programs

Presumably, the Connecticut DPH used the 40 ug/ft2 hazard level because no other lead

dust contamination standard was available. It is important to note, however, the EPA hazard

level was developed for residential dwellings occupied by children under six years old, with a

specific target population of children aged one to two years (Lead; Identification of Dangerous

Levels of Lead; Final Rule. 66 FR 4, 01/05/2001). This setting and target population is

significantly different than public school art rooms occupied by adults and older children. It is

difficult to imagine that any health benefit gained from decontaminating the art rooms to the

hazard level established for children from one to two years of age is commensurate with the

effort and expense required to achieve this level.

It should be possible to derive a lead dust contamination limit appropriate for adults and

older children from the EPA hazard level by applying exposure factors that account for age-

specific differences in behavioral factors. Two obvious factors are exposure periods and

ingestion rates. Both of these factors are well documented for the EPA target population and can

be readily calculated for any other population. A preliminary study of this topic by William Rath

of 28

suggests that application of these two exposure factors would support an art room lead

contamination standard of 320 ug/ft2. If this limit had been applied in lieu of the 40 ug/ft2 limit

specified by the Connecticut DPH, six of the 18 art rooms inspected during this project would

not have required decontamination. Furthermore, the scope of the decontamination work in nine

of the 12 remaining rooms would have decreased by fifty percent or more. Applying a 320 ug/ft2

limit would have saved each of the two school systems tens of thousands of dollars that were

spent to decontaminate art rooms and replace discarded materials and supplies.

Conclusions

Lead-bearing ceramic art glazes can cause significant and persistent lead contamination

in art studios and classrooms.

Lead contamination in art classrooms can be reduced to 40 ug/ft2 or less using standard

decontamination methods

Trace amounts of lead in “lead free” ceramic art gazes have the potential to contaminate

kilns and other art classroom surfaces

Adverse health effects from lead-bearing art materials can be minimized by following the

ASTM Guidelines for the Safe Use of Hobby Ceramic Art Materials.

Age and activity appropriate lead dust contamination standards should be derived

whenever the EPA lead dust hazard level of 40 ug/ft2 is contemplated for use for

populations other than children under six years of age in residential dwellings.

References

ACGIH. TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents.

Cincinnati, OH, 2001.

of 28

American Art Clay Company, Inc. Material safety data sheet, Lead / cadmium gloss glazes,

Product code: LG series. 2005. Indianapolis, IN.

American Society for Testing and Materials, Safety Appendix to Standard Practice C1023,

Labeling Ceramic Art Materials for Chronic Adverse Health Hazards. 2006.

http://duketox.mc.duke.edu/recenttoxissues.htm

Duncan Enterprises. Material safety data sheet, Leaded ceramic glaze. 2005. Fresno, CA:

Goldwater, LJ, Wysocki, LM, Volpe, RA, eds. Edited Proceedings: Lead Environmental Health -

The Current Issues. May 29 - 30, 1985, Duke University. Published by Division of Occupational

Medicine, Duke University, Durham, North Carolina, USA.

Rath WR. Identifying lead dust contamination limits appropriate for adults and older children.

2006. http://duketox.mc.duke.edu/recenttoxissues.htm

Roberge RJ, Martin TG, Dean BS, Lasek RW. Ceramic lead glaze ingestions in nursing home

residents with dementia. Am J Emerg Med. 1994 Jan;12(1):77-81.

Stopford W. Safety of lead-containing hobby glazes. North Carolina Medical Journal, 1988; 49:

31-34.

Stopford W., Stanion CV. Lead Contamination in Contemporary Ceramics Studios:

Potential for Community and Worker Exposure. Research Report Submitted to the American

Society for Testing and Materials in Support of Test Method C1023, Labeling of Ceramic

Materials for Chronic Health Hazards, 1998. http://duketox.mc.duke.edu/recenttoxissues.htm

U.S. Environmental Protection Agency. Lead; Identification of Dangerous Levels of Lead; Final

Rule. Washington, DC: 66 FR No. 4, 1206-40. Jan. 5, 2001. Codified at 40 CFR Part 745.

http://duketox.mc.duke.edu/recenttoxissues.htmhttp://duketox.mc.duke.edu/recenttoxissues.htmhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=8285980&query_hl=5&itool=pubmed_docsumhttp://duketox.mc.duke.edu/recenttoxissues.htm

ATTACHMENT 1

CT DPH ADVISORY ”USE OF LEADED CERAMIC GLAZES IN SCHOOL ART CLASSES”

Page 1 of 3

ATTACHMENT 1


Page 2 of 3

ATTACHMENT 1


Page 3 of 3

ATTACHMENT 2

PRE-ABATEMENT LEAD WIPE SAMPLE DATA FROM A HIGH SCHOOL ART ROOM

SAMPLE

LOCATION WIPE

AREA (IN2) RESULT (UG/FT2)

Page 1 of 2

XXHS-0413-00 FIELD BLANK (RESULTS ARE IN MICROGRAMS PER WIPE) N/A

ATTACHMENT 2

PRE-ABATEMENT LEAD WIPE SAMPLE DATA FROM A HIGH SCHOOL ART ROOM

SAMPLE

LOCATION WIPE


Page 2 of 2

XXHS-0413-20 STORAGE ROOM, VCT FLOOR, CENTER OF ROOM 144 92.0

XXHS-0413-21 STORAGE ROOM, PAINTED METAL SHELF, WEST SIDE SHELVES, SECOND SHELF FROM BOTTOM

144 42.0

XXHS-0413-22 KILN ROOM, VCT FLOOR IN FRONT OF KILN 144 450.0

XXHS-0413-23 KILN ROOM, PAINTED METAL SHELF, POTTERY STORAGE SHELVES IN SOUTHEAST CORNER, BOTTOM SHELF

144 300.0

XXHS-0413-24 KILN ROOM, EXHAUST DUCT GRILL (NOTE: THE “AREA” RECORDED FOR THIS SAMPLE IS THE GROSS AREA OF THE RETURN AIR GRILL. BECAUSE THIS GRILL IS MOSTLY OPEN SPACE, THE ACTUAL AREA OF THE SURFACE THAT WAS WIPED IS SIGNIFICANTLY LESS.)

441 130.0

ATTACHMENT 3

PRE-ABATEMENT LEAD WIPE SAMPLE DATA FROM A MIDDLE SCHOOL ART ROOM

SAMPLE

LOCATION WIPE


Page 1 of 2

XXMS-0413-00 FIELD BLANK (RESULTS ARE IN MICROGRAMS PER WIPE) N/A

ATTACHMENT 3

PRE-ABATEMENT LEAD WIPE SAMPLE DATA FROM A MIDDLE SCHOOL ART ROOM

SAMPLE

LOCATION WIPE


Page 2 of 2

XXMS-0413-20 ART ROOM 103 STORAGE ROOM/DARKROOM, VCT FLOOR, CENTER OF ROOM

144 57.0

XXMS-0413-21 ART ROOM 103 STORAGE ROOM/DARKROOM, LAMINATE PANEL, TOP OF UNIT VENTILATOR

136

ATTACHMENT 4

PRE-ABATEMENT LEAD & CADMIUM WIPE SAMPLE DATA FROM AN ELEMENTARY SCHOOL ART ROOM

SAMPLE

LOCATION WIPE AREA (IN2)

LEAD (UG/FT2)

CADMIUM (UG/FT2)

Page 1 of 1

XXES-0328-01 VCT FLOOR, CENTER OF ART ROOM 144

ATTACHMENT 5

POST-ABATEMENT LEAD WIPE SAMPLE DATA ITEMS DECONTAMINATED AND REMOVED FROM A HIGH SCHOOL ART ROOM

SAMPLE

LOCATION WIPE


Page 1 of 3

XXHS-0517-06 VINYL COVER OF 3-RING BINDER, “GLAZE BOOK BY DENNIS ROCCHIO”, DECONTAMINATED AND REMOVED FROM ROOM B116

121

ATTACHMENT 5


SAMPLE

LOCATION WIPE


Page 2 of 3

XXHS-0519-05 MISCELLANEOUS PLASTIC BOTTLES AND JARS, DECONTAMINATED AND REMOVED FROM B 116

32 OZ, “MODGE PODGE” MATTE

16 OZ. CRAYOLA TEMPURA

8 OZ. LEAK DETECTOR

179

ATTACHMENT 5


SAMPLE

LOCATION WIPE


Page 3 of 3

XXHS-0520-05 OUTSIDE SURFACES OF SMALL (8-INCH DIAMETER) TABLE-TOP KILN (ONE OF TWO), DECONTAMINATED AND REMOVED FROM ROOM B 116

71

ATTACHMENT 6

POST-ABATEMENT LEAD WIPE SAMPLE DATA HIGH SCHOOL ART ROOM INTERIOR SURFACES AND EQUIPMENT

SAMPLE

LOCATION WIPE


Page 1 of 1

XXHS-0522-02 BUTCHER BLOCK TABLE TOP, NORTH WORK TABLE ON EAST SIDE

144 12.0

XXHS-0522-03 WOOD TOP, STORAGE BIN CABINET NEAR KILN ROOM DOOR 144

ATTACHMENT 7

HIGH SCHOOL ART ROOM CERAMIC ART GLAZE WASTE INVENTORY

Page 1 of 1

INVENTORY OF LIQUID CERAMIC GLAZES IN WASTE BARREL #1

ACCORDING TO THE MANUFACTURERS’ LABELS ON THE CONTAINERS, THESE LIQUID GLAZES CONTAIN LEAD, CADMIUM, COPPER, COBALT, LITHIUM AND/OR MANGANESE

MANUFACTURER PART

NUMBER COLOR

JAR SIZE (FL. OZ.)

NO. OF JARS

AMACO LG 2 BLACK 16 1

AMACO LG 53 FLAME 16 4

AMACO LG 133 PINKISH BROWN 16 3

AMACO LT 24 ANTIQUE BLUE 16 5

AMACO LT 48 MOSS AGATE 16 2

AMACO LT 113 SAND 16 2

AMACO LT 115 FROSTED JADE 16 4

AMACO LT 122 DARK BLUE 16 2

AMACO LT 142 ANTIQUE GREEN 16 7

DUNCAN GL 610 CLEAR DIPPING GLAZE (ONE 5-GALLON BUCKET)

640 1

DUNCAN GL 612 TRANSPARENT GLOSS GLAZE (FIVE 1-GALLON JUGS)

128 5

DUNCAN GL 632 TANGERINE 16 1

DUNCAN GO 134 CALYPSO RED 16 1

MAYCO AG 251 BLACK BEAUTY 16 1

MAYCO CG 721 CANDY CANE 16 1

ATTACHMENT 8

HIGH SCHOOL ART ROOM TCLP SAMPLE DATA

SAMPLE

MATERIAL

LOCATION

ANALYTE RESULT (MG/L)

Page 1 of 2

XXHS-01 REPRESENTATIVE SAMPLES OF THE FOLLOWING MATERIALS IN BAGGED WASTE:

ARTIST’S CRAYONS

CANVAS

CHALK

CLAY DEBRIS, DRIED

CLAY DEBRIS, FIRED

CLAY DEBRIS, GREEN

CLAY PALLETS, FIBERBOARD

CLAY PALLETS, MASONITE

CLAY TOOLS

COLORED PENCILS

CORD

CORRUGATED CARDBOARD

DECORATING WHEEL – METAL

DINING UTENSILS, PLASTIC

DOWELS, WOOD

ERASERS

EXPANDED POLYSTYRENE “PEANUTS”

FABRIC

KRAFT PAPER COVERED WITH SPILLED PAINT

LATEX GLOVES

NEWSPAPERS

PAINTER’S PALETTE, CARDBOARD

PLASTER MIXING TUB, PLASTIC

RAWHIDE

REFRACTORY BRICK

SANDPAPER

SPONGE MOP HEAD

SPONGE PACKING

SPONGES

STRING

TRAYS, PLASTIC

WORK GLOVES

BAGGED WASTE

LEAD 1.0

ATTACHMENT 8

HIGH SCHOOL ART ROOM TCLP SAMPLE DATA

SAMPLE

MATERIAL

LOCATION

ANALYTE RESULT (MG/L)

Page 2 of 2

XXHS-02 REPRESENTATIVE SAMPLES OF THE FOLLOWING MATERIALS IN BARREL #2:

CARPET FROM FRONT OF SINKS

CLEANING RAGS

CLOTH APRON

SPONGE MOP HEAD (DIRTY)

BARREL # 2 LEAD 0.99


CLEANING RAGS

DIP-GLAZE DRUMS (PLASTIC)

PAINTBRUSHES



CLEANING RAGS

COVERALLS (DISPOSABLE SPUN FABRIC)



CLEANING RAGS (CLOTH)

CLEANING RAGS (PAPER)

KILN STILTS (BROKEN)



CLEANING RAGS (CLOTH)

CLEANING RAGS (PAPER)


ATTACHMENT 9

RECOMMENDATIONS FOR KILN OPERATIONS

Page 1 of 1

RECOMMENDATIONS FOR KILN OPERATIONS

During the course of our study of kiln contamination issues, IH&SC contacted four kiln manufacturers, the Edward Orton Jr. Ceramic Foundation, the Art & Creative Materials Institute, Inc. (ACMI - the people that provide the standards for the safety labels on art materials), and the American Society for Testing & Materials (ASTM). Based upon our interviews with these organizations, we have developed the following ceramic art operations guidelines that will minimize lead contamination and minimize the risk from the contamination that may be inevitable, even when using “lead-free” glazes: 1. Before resuming glazing operations, operate the kiln at maximum temperature

for two hours with downdraft ventilation, followed by a normal cool-down 2. HEPA vacuum the inside of the kiln to remove all dust and debris (note that kiln

manufacturers recommend vacuuming the kiln after every firing to minimize dust that could adversely affect the finished product)

3. Always operate the kiln and kiln ventilation system in strict accordance with the

manufacturer’s instructions 4. Use only "lead free" glazes marked "AP Non-Toxic" 5. Relocate the kilns that are within classrooms to separate rooms that are not

routinely occupied by students 6. Follow the ASTM "Guidelines for the Safe Use of Hobby Ceramic Art Materials" 7. Conduct a follow-up evaluation after six months of use to verify the

implementation and effectiveness of these guidelines.

classroom contamination from lead bearing ceramic art glaze … · 2018. 1. 31. · ceramic art...

Documents