Page 1 of 4 

This working document was prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in 

discussions with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final 

NIOSH or ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents 

preliminary positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and 

redact any information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

NIOSH Response to Sanford Cohen & 

Associates Review of Hooker 

Electrochemical Company TBD 

(DCAS-TKBS-0009 Rev. 3)

Response Paper 

National Institute for Occupational Safety and Health 

Division of Compensation Analysis and Support 

December 6, 2016 

By David Allen 

Reviewed by James W. Neton, Ph.D., CHP 
Response Paper Review of DCAS-TKBS-0009 Rev. 3 (Hooker Electrochemical Co.) 

Page 2 of 4 

This working document was prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in 

discussions with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final 

NIOSH or ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents 

preliminary positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and 

redact any information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

Background 

On November 22, 2016, SC&A delivered a review of revision 3 of the Hooker Electrochemical 

Company TBD (DCAS-TKBS-0009). The review considered the resolution to findings 4, 5 and 

6 of review of revision 2 of the TBD. SC&A recommended closing findings 5 and 6, but had 

additional concerns for finding 4. This white paper discusses those concerns. 

Finding 4 essentially noted that revision 2 of the document did not include ingestion intakes. 

During a meeting of the URAWE working group held 7/19/2016, NIOSH stated that the Hooker 

TBD failed to include ingestion but the dose reconstructions have included ingestion intakes 

utilizing DCAS-TIB-009. NIOSH agreed the discussion should be added to the TBD. 

In SC&A’s review, they compared the ingestion technique used in TKBS-0009 to that in the 

DuPont Deepwater Works TBD (TKBS-0006) and raised several concerns. These concerns in 

part are caused by a misunderstanding of what was discussed in past work group meetings. In 

order to clarify past discussions and resolve the current concerns, it is necessary to discuss some 

of the background information first. 

Use of TIB-009 during Residual Periods 

SC&A indicated there was general agreement that methodology prescribed in TIB-009 was not 

acceptable for estimating ingestion intakes during the residual period. This is not entirely 

accurate. TIB-009 correlates ingestion intakes to airborne concentrations that were generated 

from activities conducted during the operational period. During those evolutions, the 

operation causing the airborne concentration is also causing surface contamination. The surface 

contamination in turn is related to the ingestion rate so it is possible to correlate airborne 

concentrations to ingestion rate without the intermittent step of calculating a surface 

contamination value. 

The previous discussion, associated with DuPont, was related to the use of the TIB-009 

methodology to estimate ingestion intakes based on resuspended airborne contamination during 

the residual period. While it may be possible to develop a conversion factor correlating 

resuspended airborne contamination to ingestion rate, TIB-009 did not do that and NIOSH agrees 

that it was inappropriate to use it in that manner. 

It was also discussed, however, that while the airborne concentrations decrease rapidly after the 

cessation of operations, there is no reason to believe the same is true of the surface 

contamination levels. Therefore, there is no reason to believe the ingestion rate is reduced 

rapidly. It is therefore possible to use TIB-9 with the operational airborne concentrations to 

determine the ingestion rate at the end of the operational period. Because there is no reason to 

believe the ingestion rate decreased quickly, it is also appropriate to use this rate at the start of 

the residual period. 

To summarize, the general agreement was that it is not appropriate to use TIB-009 with the 

resuspended airborne values of the residual period, but it is appropriate to use the operational 
Response Paper Review of DCAS-TKBS-0009 Rev. 3 (Hooker Electrochemical Co.) 

Page 3 of 4 

This working document was prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in 

discussions with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final 

NIOSH or ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents 

preliminary positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and 

redact any information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

period ingestion rate (determined using TIB-009) in the residual period. As SC&A calculations 

showed, this is what was done in revision 3 of the Hooker TBD. 

Inconsistency between NRC ingestion value and TIB-009

SC&A noted that for the DuPont Deepwater Works TBD, NIOSH used an NRC conversion 

factor of 1.1E-4 m2/hr to calculate ingestion intakes. This factor comes from NUREG/CR-5512. 

SC&A compared this to the ingestion rate calculated using TIB-009 and determined the TIB-9 

approach was 8.5 times lower. 

In order to perform this comparison it was necessary for SC&A to estimate a surface 

contamination value utilizing the technique in TBD-6000. That technique relies on a 

conservative default value of 30 days for settling time. The data analysis used to derive that 30 

day value calculated the value four different ways, resulting in values of 5.8, 7.1, 15 and 27 days 

(NIOSH 2009). The 30 day default was chosen as a conservative value by rounding the highest 

value up. When the issue was raised again (SCA 2013), another analysis indicated the most 

appropriate value would likely fall between 2.97 days and 4.6 days (NIOSH 2013) but the 

conservative 30 days was retained as a favorable assumption. These values are in the range of 

8.5 times lower than the 30 day settling time used in the TBD-6000 technique. This indicates 

that there is no demonstrated inconsistency between the ingestion techniques. The inconsistency 

is actually in the surface contamination estimate because it is based on a very conservative 

default value. For this situation at least, it would appear that the TIB-009 technique is likely the 

more accurate approach and the approach using of the NRC value is hampered by the 

conservative default value used for settling time. 

Inconsistency between DuPont Deepwater Works and Hooker TBDs 

SC&A implied in its report that the two techniques are inconsistent and NIOSH needs to clarify 

why one procedure was used for DuPont and a different one for Hooker. 

NIOSH attempts to use the best available data in estimating doses. The type of data available 

differs from site to site causing the most appropriate technique to differ from site to site. These 

two sites are actually a perfect example of this situation. 

As stated earlier, the ingestion rate determined in the operational period is appropriate for use at 

the start of the residual period since it is not normally expected that the surface contamination 

would decrease quickly at the end of operations (without some cleanup). Therefore it is 

appropriate to use TIB-009 at the Hooker plant. This is not the case at DuPont. At the end of 

operations, the facility was decontaminated by washing as well as sandblasting as much as 0.04 

inches of concrete from the surfaces. At the end of the decontamination, a survey was performed 

indicated all areas were less than 500 dpm/100 cm2. Therefore, at DuPont, there is a disconnect 

between the operational period contamination levels and the residual period contamination 

levels. Moreover, there is measurement data of the contamination levels at the start of the 

residual period. Since TIB-009 essentially assumes no decontamination, it would not be 

appropriate to use it for DuPont. Also, with measured contamination levels, it would not be 
Response Paper Review of DCAS-TKBS-0009 Rev. 3 (Hooker Electrochemical Co.) 

Page 4 of 4 

This working document was prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in 

discussions with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final 

NIOSH or ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents 

preliminary positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and 

redact any information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

appropriate nor necessary to model the contamination levels. The technique that would use the 

best available data would be to use the measured contamination levels with the NRC conversion 

factor as was done for DuPont. 

References

NIOSH 2009, Dave Allen, Battelle-TBD-6000 Issue 5 White paper, Comparison to Adley 

Contamination Data, October 9, 2009, starting on page 19 of 

http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-gsi-tbdim-100710.pdf

SCA 2013, William C. Thurber, Supplementary Comments on Revision 01 of Battelle-TBD-6000, 

May 2013, http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-tbd6000-r0.pdf

NIOSH 2013, David Allen, TBD 6000 Review by SC&A, Determination of Settling Time, August 

2013, http://www.cdc.gov/niosh/ocas/pdfs/dps/dc-tbd6000-0813.pdf