Evaluation and Management of Mercury-Containing Floors in New

Evaluation and Management

of Mercury-Containing Floors

in New Jersey Schools:

Guidance for School Districts

and their Environmental

Consultants

February 6, 2020

ealth Consultation

prepared by:

ew Jersey Department of Health

Environmental and Occupational Health Surveillance Program

Table of Contents

Purpose.......................................................................................................................................... 2

Introduction.................................................................................................................................... 2

Steps for Assessment of Flooring.............................................................................................. 3

Sampling Plan Overview ............................................................................................................. 4

Bulk Sampling ........................................................................................................................... 4

Indoor Air Sampling.................................................................................................................. 5

Risk Assessment .......................................................................................................................... 7

Evaluate and Mitigate Exposures .............................................................................................. 7

Disposal of Floor Materials ......................................................................................................... 8

Purpose

This guidance document provides a systematic approach for school districts and

their environmental consultants to evaluate whether installed mercury-containing

flooring systems emit mercury vapors in excess of New Jersey Department of Health’s

(NJDOH) recommended maximum contaminant level of 0.8 micrograms per cubic meter

(µg/m

) of air.

Introduction

In the 1960s, a number of companies began manufacturing and installing a thin

layer of synthetic, polyurethane flooring on top of concrete sub-floors, to provide a

resilient and rubberlike surface (ATSDR 2010; ATSDR 2006a; ATSDR 2006b).

Typically, liquid polyurethane was poured directly over concrete sub-floors, and in some

cases over a rubberized shock-absorbing cushion material. Certain formulations of

polyurethane incorporated mercury catalysts, such as phenylmercuric acetate (PMA), to

produce a solid, seamless rubber-like floor. Depending on the required thickness of the

floor, multiple pours of polyurethane were often employed. The concentration of

mercury in such polyurethane flooring systems are reported to contain between 0.1 and

0.2 percent total mercury (Bush 2011; ATSDR 2006a; Reiner 2005).

Mercury-containing polyurethane floors were widely installed in school

gymnasiums across the United States until being reportedly discontinued amid

concerns over their emissions of elemental mercury vapor (NEWMOA 2010). It is to be

noted that depending on the type and brand of polyurethane flooring, these floors may

have been installed even as late as in 2005 or 2006 (Washington Township, New

Jersey 2019; Bush 2011).

The following list of manufacturers are consistently referenced as having

produced polyurethane products known to contain PMA in their formulation (Garrison,

2019). It is important to recognize this list is not an all-inclusive list. It is believed other

manufacturers may also have included mercury catalysts in their polyurethane flooring

systems.

• 3M under the name of Tartan® floors and Tartan® track

• American Biltrite Rubber Co. Inc.

• Amtico Rubber Flooring

• Athletic Polymer Systems (APS)

• Chemothane

• Crossfields Products (DexOTex)

• Mondo Rubber

• Pitzer Inc.

• Pulastic Systems

• Robbins Sport Surfaces - Chemturf

• Selby Battersby & Company Surfacing Systems

• Sportan Surfaces, Inc.

• Whittaker Synthetic Surfaces

Studies have shown that some of these flooring systems emit mercury vapor into

the indoor air, leading to a concern about mercury exposures in schools. It is not known

how many of these floors currently exist, whether they are still being installed, or what

schools have them (ATSDR 2004; ATSDR 2006a; ATSDR 2006b; ATSDR 2010; Bush

2011; Garrison 2019).

This document provides guidance to school districts investigating the potential

mercury vapors being emitted from these floors.

Steps for Assessment of Flooring

1. School districts should conduct a visual inspection to determine if poured-

polyurethane floors (soft material in one contiguous piece that is clearly not wood

or tile) have been installed in the school. If this type of flooring is identified in the

school, a licensed indoor environmental consultant should be hired. A list of

these consultants can be found on the Department’s website at:

NJDOH-licensed Indoor Environmental Consultant

2. Check if the manufacturer is noted in the list above and/or review the floor’s

Safety Data Sheet (SDS) for PMA. If the presence of PMA is confirmed, then skip

step 3 below (as bulk sampling is not necessary to confirm the presence of

mercury). It is not possible to rule out the potential presence of mercury based on

the list above as other flooring system manufacturers and installers may have

incorporated PMA in their polyurethane formulations. Further, the SDS may not

be conclusive as the company might list the PMA ingredient as proprietary

information.

3. If the record review was inconclusive, the district and its consultant may choose

to collect a bulk sample of the flooring material to test for the presence of

mercury. A bulk sampling plan overview is outlined below for the consultant to

follow. The consultant will determine the timing between the bulk sampling and

any indoor air sampling as these should not occur concurrently. The bulk

sampling test may be informative in confirming there is no mercury present. The

bulk sample must be analyzed by an American Industrial Hygiene Association

(AIHA) accredited laboratory available at: aihaaccreditedlabs.org/

4. If the record review or bulk sampling confirmed the presence of mercury in the

flooring, an appropriate air testing and monitoring program is warranted.

sampling plan overview is outlined below for your consultant to follow

Sampling Plan Overview

A sampling plan that includes specific sampling and analytical methods is critical

for evaluating mercury levels contained in synthetic flooring and the mercury levels in

the indoor air. The district should hire and work with a licensed environmental

consultant to understand the sampling plan before the plan is implemented. The

consultant must provide sampling protocols, procedures, and an understanding of how

to interpret the results to the district. The details for these procedures are provided in

the sections below.

Bulk Sampling

The purpose of the bulk sampling is to determine if mercury is present in the

flooring material and if indoor air monitoring is necessary. A sampling plan must be

developed to ensure that the bulk samples are representative of the floor area(s) being

evaluated. As noted above, the consultant will determine the timing between the bulk

sampling and any indoor air sampling as these should not occur concurrently. The plan

must include a diagram of the floor(s) showing the sampling locations and the laboratory

results of the bulk samples. The environmental consultant should identify the rooms that

contain the suspect flooring, coordinate the collection of bulk samples with school

facilities staff, and execute the bulk sampling plan. The environmental consultant must

ensure that all floor sampling locations are sealed and repaired after the bulk samples

are collected.

Sampling Methods and Procedures

1. An appropriate size sample of the flooring material needs to be collected for

analysis. The thickness of most poured polyurethane floors typically ranges from

¼-inch to 1-inch. Bulk samples of rubberized floor must represent the entire

thickness/depth of the floor material. Sampling of only the surface or partial

thickness of the floor must be avoided. Coring tools are commonly used to collect

the bulk sample of the floor material. The environmental consultant must provide

information on the bulk sample collection tools as well as the procedure to collect

the sample from the entire thickness of the floor.

2. The recommended number of samples is: one floor sample from rooms that are

less than 1,000 square feet, two samples from rooms 1,000 to 5,000 square feet,

and three samples from rooms greater than 5,000 square feet. The sample

locations should be selected, to the extent possible, in areas where the sample

extraction is less likely to present a visual blemish (such as in room corners, in

closets, behind doors, etc.)

Bulk samples of floor material must be analyzed using USEPA Method 7471B to

determine the mercury content. An accredited laboratory should be contacted to ensure

the proper amount of floor material is being collected. Typically, laboratories require 10

grams of floor material to analyze for mercury content.

If the floor contains mercury at any concentration, the NJDOH recommends

sampling of the indoor air to evaluate the mercury vapor levels.

Indoor Air Sampling

The primary route of exposure to mercury vapor is through inhalation. Therefore,

it is important to conduct air sampling to provide data which characterizes the mercury

vapor levels in the indoor air.

General Requirements

• An indoor air sampling plan must be developed before any samples are

collected. The sampling plan should ensure that air samples are taken from

several locations to be representative of the floor area or room being evaluated.

Samples should be collected at the breathing zone level, which is typically

between three to five feet above the floor. Your consultant should include

procedures for using a direct read instrument, the NIOSH 6009 method or both in

the plan. See below for general sampling requirements using these methods. For

all sampling plans, a diagram of the floor area or room showing the locations of

the air samples must be developed. Sampling adjacent hallways and rooms

should be included in the sampling plan. Ambient readings should be collected

outside the facility to establish background levels.

Airborne mercury levels are affected by the operation of the Heating, Ventilation

and Air Conditioning (HVAC) system. Given this relationship, the indoor air samples

should be collected under typical HVAC operational conditions. Sampling under these

conditions will represent the typical ventilation and temperature conditions under which

the building is being maintained and occupied. The room temperature and typical

operational settings of the HVAC system should be documented prior to collecting any

air samples.

Field notes should include a visual inspection of the condition of the floor at

locations where samples are collected, specifically noting if the floor surface is

compromised in any manner.

Sampling Methods and Procedures

The following two widely used sampling and analytical methods are available for

quantifying mercury levels in the indoor air.

1. Direct Reading Instruments:

• The Lumex RA-915M Mercury Vapor Analyzer (OhioLumex Co., Inc.,) or the

Jerome J505 (AMETEK Arizona Instrument) can be used to measure mercury

vapor concentrations in air. These direct read instruments are portable mercury

vapor analyzers that have very little cross-sensitivity to chemicals other than

elemental mercury. These instruments have low detection limits (ranging from

0.002 micrograms per cubic meter (µg/m

) to 0.05 µg/m

) and can measure

mercury vapor levels under a variety of sample collection protocols.

Sample Collection Procedures

• Ensure that the instrument has been properly calibrated according to the

manufacture’s recommended procedures. Calibration records must be retained

to document that the instrument is functioning correctly.

• Temperature, humidity, and air pressure measurements must be collected during

the sampling events.

• Direct read measurements should be taken in a predetermined pattern

throughout the gym/room where the flooring material is located.

• Direct reading measurements should be taken at various heights above the floor.

• Readings collected at locations where the floor surface is compromised should

be noted.

2. Industrial Hygiene Sampling:

• NIOSH Method 6009 - Analysis of Mercury in Air, is a common method for

collecting airborne mercury vapors for laboratory analysis. Using this method,

samples may be collected over customized periods of time to represent typical

occupied conditions. The sample collection method includes a solid sorbent tube

(Hopcalite sample collection media) which is connected to a properly calibrated

sampling pump. Sampling pumps must be calibrated using a recognized primary

standard to document the sampling flowrate. The NIOSH 6009 method should be

consulted for the sample collection flowrates and detection limits.

Sample Collection Procedure

• To be representative of the gym/room, three to five samples should be collected.

The number of samples within the gym/room may vary depending on the size of

the room being evaluated. When determining the number of samples to be

collected, the consultant should ensure that there are a sufficient number of

samples to represent the gym/room and adjacent areas being evaluated.

• Temperature, humidity, and air pressure measurements must be collected during

the sampling events.

• Samples should be collected at a height between three and five feet above the

floor.

• The sampling time should be between six to eight hours to represent a typical

day within the gym/room.

• Samples should be collected at a flowrate between 0.20 – 0.25 liters per minute

(LPM)

• Collect between 90 and 100 liters of air to ensure that the lowest limit of detection

(LOD) for the method is reached.

• Record the sampling information on a chain of custody form for submission to the

accredited laboratory.

• Follow the quality control procedures outlined in the method for the submission of

blank samples to the laboratory.

• Submit the samples to an accredited laboratory for analysis.

Risk Assessment

The primary exposure to mercury vapor is by inhalation. The NJDOH has

adopted Standards for Indoor Environment Certification and for Licensure of Indoor

Environmental Consultants (N.J.A.C. 8:50

). These regulations provide a risk

assessment model that can be used to evaluate indoor air contaminants for school

children and staff. This model is very conservative and adjusts for body weight,

inhalation rate, and the amount of time spent in school for both children and staff. Based

on the toxicological information and this regulated risk assessment model, the NJDOH

has issued a guidance maximum contaminant level of 0.8 µg/m

for evaluating mercury

in flooring. This level is protective for children as young as three years old and is

based on an exposure frequency of 8-hours per day for 180 days (NJDOH 2017).

The NJDOH acknowledges that there are other guidance levels for mercury vapors

established by ATSDR, USEPA and other states, but there is no national standard

(ATSDR 2004; 2006a; 2006b; 2010; Bush 2011; OEHHA; USEPA). The NJDOH

guidance value is based on the exposure scenario in the risk model that is protective of

preschool-aged children and a level at which adverse health effects are not likely to

occur.

Evaluate and Mitigate Exposures

Based on the air sampling results, school districts may encounter the following

scenarios:

Airborne mercury levels lower or equal to 0.8 µg/m

• Continue to use the gym/room under the occupied conditions that the samples

were collected.

• Quarterly, seasonal sampling is recommended to ensure that the seasonal

variability’s impact on mercury concentrations is captured. Assessing the

seasonal mercury level variation will ensure that the mercury indoor air level is

always lower than 0.8 µg/m

. Mercury vapor levels are related to temperature, so

it is important to test during all seasons, especially during the heat of the

summer.

• Maintain the room temperature and ventilation system to remain consistent with

the operations at the time of sampling.

nj.gov/health/ceohs/documents/eohap/njac_850_adoption.pdf

• If conditions of the flooring change, i.e., if there are cracks or other signs of

deterioration or damage, resampling of mercury vapors in indoor air is necessary.

• Mercury vapor levels can be managed by active ventilation and temperature

control of the room.

Airborne mercury levels above 0.8 µg/m

• Work with the environmental consultant to develop a feasible plan to reduce the

mercury vapor levels below 0.8 µg/m

. Mercury vapor levels can be reduced by

active ventilation and temperature control of the room.

• Make adjustments to the HVAC system including increasing the ventilation/fresh

air intake and/or lowering the temperature in the room. Verify (by retesting) that

these adjustments have reduced mercury vapor levels to equal to or less than

0.8 µg/m

• If these adjustments are inadequate to maintain the levels to 0.8 µg/m

or below,

reduce the amount of time spent in the room to less than 8 hours per day or do

not allow use of the room.

• If ventilation adjustments sufficiently reduce the levels to less than or equal to 0.8

µg/m

, monitor the indoor air at least quarterly to evaluate the mercury levels

during other seasons.

• If ventilation adjustments do not sufficiently reduce the levels to less than or

equal to 0.8 µg/m

, additional actions including removal of the flooring should be

considered. Discussions with the environmental consultant will be needed to

determine the appropriate course of action.

In addition, the gym floor should be cleaned using non-abrasive cleaning methods to

avoid damaging the floor which could result in an increase in mercury emissions into the

air.

Disposal of Floor Materials

If the flooring contains mercury and a decision is made to remove it, a

determination needs to be made whether the material would be regulated as a

hazardous waste for disposal. Contact the NJDEP’s Division of Sustainable Waste

Management

for information on the proper disposal of the flooring material. The

Division of Sustainable Waste Management can be reached at (609) 633-1418 or (609)

984-0565.

For general questions, please contact the NJDOH - Consumer, Environmental, &

Occupational Health Services at 609-826-4920.

nj.gov/dep/enforcement/hw.html; nj.gov/dep/dshw/

References

ATSDR 1999. Agency for Toxic Substances and Disease Registry. Toxicological profile

for mercury. Atlanta: U.S. Department of Health and Human Services.

ATSDR 2004. Agency for Toxic Substances and Disease Registry Mid-Michigan

Mercury Floor, Middleton, Gratiot County, Michigan. Michigan Department of

Community Health (MDCH). Available at:

atsdr.cdc.gov/HAC/pha/Mid-

MichiganMercuryFloor050604-MI/Mid-MichiganMercuryFloorHC050604.pdf

ATSDR 2006a. Agency for Toxic Substances and Disease Registry Mercury-Containing

Polyurethane Floors in Minnesota Schools. Mercury Vapor Release/Athletic Polymer

Floors. Available at:

atsdr.cdc.gov/HAC/pha/MercuryVaporReleaseAthleticPolymerFloors/MercuryVaporRele

ase-FloorsHC092806.pdf

ATSDR 2006b. Agency for Toxic Substances and Disease Registry Health

Consultation: Salem-Keizer School District 3M Flooring. Prepared by Oregon

Department of Human Services Superfund Health Investigation and Education Program

(SHINE) Salem, Oregon. Available at:

atsdr.cdc.gov/HAC/pha/SalemKeizerSchoolDistrict/Salem-KeizerSchoolHC071206.pdf

ATSDR 2010. Agency for Toxic Substances and Disease Registry Health Consultation.

Evaluation of Health Concerns Associated with Mercury-Containing Polyurethane

Gymnasium Floor in a Milwaukee Public School. Prepared by: The Wisconsin

Department of Health. Available at:

atsdr.cdc.gov/HAC/pha/MilwaukeePublicSchool/MPSGymFloorMercury12162010.pdf

Bush. Christina., et al. (2011). Mercury Emissions from PMA-Catalyzed Polymer Floors:

Investigations, Mitigation, and Education. Available at:

isiaq.org/docs/presentations/0434_Bush.pdf

Garrison, R. (2019). The Hazards Associated with Mercury containing Polymer Flooring

Materials in School Gymnasiums, Terracon, 10841 S. Ridgeview Road, Olathe, KS

66061.

(NEWMOA) 2010. Northeast Waste Management Officials' Association 2010. Mercury

Legacy Products in Schools. Available at:

newmoa.com/prevention/mercury/projects/legacy/schools.cfm

NJDOH 2017. New Jersey Department of Health. September 2017. Guidance for New

Jersey Schools: Evaluating Mercury in Synthetic Flooring. Available at:

https://www.nj.gov/health/ceohs/documents/NJDOH_mercury_flooring_guidance.pdf

OEHHA 2014. California Environmental Protection Agency’s Office of Environmental

Health Hazard Assessment. Appendix D. Individual Acute, 8-Hour, and Chronic

Reference Exposure Level Summaries pages 476-501. Available at:

oehha.ca.gov/media/downloads/crnr/appendixd1final.pdf

Reiner, E.A. (2005). Letter to C. Herbrandson, Minnesota Department of Health. Re:

Questions About Rubber-Like Floors. 3M Environmental Health and Safety Operations,

St. Paul, MN. September 23, 2005.

USEPA 1995. U.S. Environmental Protection Agency. Integrated Risk Information

System (IRIS) U.S. Chemical Assessment Summary. Available at:

epa.gov/ncea/iris/iris_documents/documents/subst/0370_summary.pdf

Washington Township Public Schools, Gloucester County, New Jersey March 2019.

Rubberized Flooring Mercury Investigation – Occupied Air Sampling Report. March 26,

2019.

Technical Resources

Analytical Methods for Mercury

• EPA 7471B Mercury in solid or semisolid waste (manual cold-vapor technique)

epa.gov/sites/default/files/2015-12/documents/7471b.pdf

• EPA TCLP Method 1311 SW-846 Test Method 1311: Toxicity Characteristic

Leaching Procedure epa.gov/sites/production/files/2015-12/documents/1311.pdf

• NIOSH Method 6009 cdc.gov/niosh/docs/2003-154/pdfs/6009.pdf

• TCLP test epa.gov/sites/production/files/2015-12/documents/1311.pdf

Sources for Direct Reading Instruments for Mercury

• Lumex of Ohio, ohiolumex.com/mercury-analyzer-915m

• Arizona Instruments/Jerome, arizona-instruments-jerome-j505-mercury-vapor-

analyzer-for-fluorescence-spectroscopy/

REPORT PREPARATION

This health consultation providing guidance for evaluation of mercury in flooring was

prepared by the New Jersey Department of Health.

Authors

Somia Aluwalia, Ph.D.

Health Assessor

Environmental and Occupational Health Surveillance Program

New Jersey Department of Health

Katharine McGreevy, MPA, Ph.D.

Program Manager

Environmental and Occupational Health Surveillance Program

New Jersey Department of Health

Gary Centifonti, M.S., CIH

Director

Consumer, Environmental and Occupational Health Service

New Jersey Department of Health

Any questions concerning this document should be directed to:

New Jersey Department of Health

Environmental and Occupational Health Surveillance Program

Consumer, Environmental and Occupational Health Service

P.O. Box 369

Trenton, New Jersey 08625-0369

Non-Certified

This publication was made possible by Grant Number NU61TS000288-02-00 from the

Agency for Toxic Substances and Disease Registry. Its contents are solely the

responsibility of the authors and do not necessarily represent the official views of the

Agency for Toxic Substances and Disease Registry, or the Department of Health and

Human Services.