Linde Ceramics Plant

Special Exposure Cohort 

Petition Evaluation Report

Revision 1

James W. Neton, Ph.D., CHP

Associate Director for Science

National Institute for Occupational Safety and Health

Division of Compensation Analysis and Support

December 2011

Tampa, FL
Petition Overview

 Petition received on November 5, 2009

 Petitioner proposed class definition:

• All employees who worked in any area at the 

Linde Ceramics in Tonawanda, NY, from 

November 1, 1947 to December 31, 1953

 Petition qualified for evaluation on 

January 22, 2010
Petition Overview—cont. 

 Class evaluated by NIOSH

• All employees who worked in any area at the Linde

Ceramics Plant in Tonawanda, NY, from November 1, 1947 

to December 31, 1953

 Covered periods at Linde Ceramics Plant

• Contract period extends from October 1, 1942 through 

December 31, 1953 

• Residual contamination continues through October 2009

 Previously added SEC classes

• October 1, 1942 through October 31, 1947

• January 1, 1954 through December 31, 1969
Evaluation Report Background 

 Original evaluation report presented to the 

Advisory Board in November 2010

 NIOSH believed at that time that all doses could 

be reconstructed with sufficient accuracy

• Ability to reconstruct internal doses largely based on 

the existence of >600 uranium urinalysis samples 

collected between 1947 and 1950

 Detailed review of available samples and 

operations between 1947 and 1953 has been 

conducted 
Linde Ceramic Plant’s AEC Activities

 Linde Ceramics Plant (a division of Linde

Air Products Corporation) located in 

Tonawanda, New York

 Originally handled uranium products used 

as dyes for ceramic tableware 

 In 1942, contracted with the Manhattan 

Engineering District (MED) to process 

uranium ores to produce uranium oxide 

and later, green salt 
Linde Ceramic Plant’s AEC Activities—cont.

 In 1942 and thereafter, the MED erected 

several buildings (30, 31, 37, and 38) at the 

site, which became known as the Linde 

Ceramics Plant

 

 The MED contracted for the processing of 

uranium ores into green salt in a 3-step 

process extending from October 1, 1942 

through June 30, 1949
Chemical Processes at Linde 

Ceramics Plant

 Step 1

• Conversion of uranium ore to U3O8 (black oxide)

• Unrefined ore contained U progeny in equilibrium

• Occurred in Building 30

 Step 2

• Conversion of U3O8 to UO2 (brown oxide)

• UO3 (orange oxide) was an intermediary product

• Occurred in Building 30

 Step 3

• Conversion of UO2 to UF4 (green salt)

• Occurred in Buildings 37 and 38
Major Operations (1947 – 1953)

 Production of UF4 in Building 38

• November 1, 1947 – June 30, 1949

• UO2 + 4HF → UF4 + 2H2O 

• Started with purified U, so no exposure to progeny

 D&D of Building 30

• Some step 2 process equipment removed starting in 

April 1948

• Extensive D&D activities (e.g., sand blasting, removal of 

contaminated parts, jack hammering) started in May 1949 

and completed February 1950

• Potential for exposure to U and progeny
Building 38 After June 30, 1949

 Decontamination efforts not well documented

 Minor cleanup performed at the end of 

operations and equipment placed in standby 

mode

 Memos indicate that decontamination efforts 

occurred sometime between 1950 and 1953 

 NIOSH has no internal monitoring data for these 

efforts
Review of Urinalysis Data

 Urine samples collected between 1947 and 1950 

measured for mass of uranium only

 Most samples appear to have been collected to 

monitor workers in Building 38 

• Fluorine results reported in addition to U

 Mass measurements incapable of evaluating intakes 

of long lived progeny present in Building 30

 No bioassay or air sample data available after 1950 

 D&D operations conducted in Building 38 sometime 

after 1950
Feasibility - Internal Dose

 Building 38 decontaminated after July 1949 by 

workers who were either unmonitored or for 

whom the monitoring records have been lost

 Building 30 contaminated with raffinate material 

and, after 1950, with residual material that 

included some raffinates of unknown 

concentration

 Available bioassay data incapable of quantifying 

exposures in either situation
Feasibility - Radon

 All above ground structures assumed to have a 10 

pCi/L radon level, per the Technical Basis 

Document, Table 3-5 

 Documentation indicates that the utility tunnels 

near the Linde Ceramics Plant (Buildings 30, 31, 37, 

and 38) were not built until after 1956

 Documentation and soil samples show that the 

Bldg. 14 area was not contaminated with radium so 

that the surface radon levels are bounding for the 

existing utility tunnel
Feasibility – External Dose

 Principal sources of exposure

• Direct beta/gamma from uranium and progeny contained 

in process material

• Residual contamination present on surfaces

 Approximately 6,000 weekly film badge results 

available 

• Allows for correlation between job category and 

measured dose

 Radiation area survey data available to supplement 

film badge data
Evaluation Process

 Two-prong test established by EEOICPA and 

incorporated into 42 C.F.R. § 83.13 (c)(1) and 42 

C.F.R. § 83.13 (c)(3):

1. Is it feasible to estimate the level of radiation doses 

of individual members of the class with sufficient 

accuracy?

2. Is there a reasonable likelihood that such radiation 

dose may have endangered the health of members of 

the class?
Feasibility of Dose Reconstruction

 NIOSH finds that the available monitoring 

records, process descriptions, and sourceterm data are insufficient to bound internal 

doses or to complete dose reconstructions 

with sufficient accuracy for the evaluated 

class of employees
Health Endangerment

  The evidence reviewed in this evaluation 

indicates that some workers in the class may 

have accumulated chronic radiation exposures 

through intakes of radionuclides and direct 

exposure to radioactive materials

 Consequently, NIOSH is specifying that health 

may have been endangered for those workers 

covered by this evaluation who were employed 

for a number of work days aggregating at least 

250 work days within the parameters 

established for this class or in combination with 

work days within the parameters established for 

one or more other classes of employees in the 

SEC 
NIOSH Recommendation

All employees who worked in any area at the 

Linde Ceramics Plant in Tonawanda, New York, 

from November 1, 1947 through December 31, 

1953, for a number of work days aggregating at 

least 250 work days, occurring either solely under 

this employment or in combination with work 

days within the parameters established for one or 

more other classes of employees in the Special 

Exposure Cohort
NIOSH Recommendation—cont. 

Summary of Feasibility

Summary of Feasibility

(November 1, 1947 through December 31, 1953)

, 1947 through December 31, 1953)

Source of 

Exposure

Feasible Not Feasible

Internal

 U and progeny X 

 Radon X 

External

 Gamma, Beta, and 

neutron

X 

Medical X (1950-1953)