DISCLAIMER: This is a working document provided by the Centers for Disease Control and Prevention (CDC) 

technical support contractor, SC&A, for use in discussions with the National Institute for Occupational Safety and 

Health (NIOSH) and the Advisory Board on Radiation and Worker Health (ABRWH), including its Working Groups or 

Subcommittees. Documents produced by SC&A, such as memorandum, white paper, draft or working documents are not 

final NIOSH or ABRWH products or positions, unless specifically marked as such. This document prepared by SC&A 

represents its preliminary evaluation on technical issues.

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.

MEMORANDUM

TO: URAWE Work Group 

FROM: SC&A, Inc.

DATE: December 23, 2016 

SUBJECT: SC&A Review of NIOSH Response Paper, NIOSH Response to Sanford Cohen & 

Associates Review of Hooker Electrochemical Company TBD (DCAS-TKBS-0009 rev. 3)

Introduction

On September 13, 2016, the National Institute for Occupational Safety and Health (NIOSH) issued 

Revision 03 to DCAS-TKBS-0009, Technical Basis Document for the Hooker Electrochemical 

Company (NIOSH 2016a, the Hooker site profile). The Work Group tasked SC&A to review 

Revision 03 with a view of determining whether all open findings from previous reviews had been 

addressed. As discussed in SC&A’s review of Revision 03, SC&A recommended that Findings 5 and 6 

be closed (SC&A 2016). With regard to Finding 4, NIOSH added an approach to addressing ingestion 

exposures during the residual period that had not been previously included (SC&A 2016). On 

November 21, 2016, SC&A requested further clarification of the specific approach taken to develop the 

ingestion exposures, because there was apparent agreement, based on prior discussions with NIOSH, 

that the approach presented in OCAS-TIB-009, Estimation of Ingestion Intakes, Revision 00 (OCAS 

2004; hereafter “TIB-009”) was not appropriate. 

NIOSH replied to SC&A’s November 2016 review on December 6, 2016, in a response paper 

(NIOSH 2016b) titled NIOSH Response to Sanford Cohen & Associates Review of Hooker 

Electrochemical Company TBD (DCAS-TKBS-0009 rev. 3). This memorandum is SC&A’s critique of 

the NIOSH response paper.

Discussion

SC&A recognizes that ingestion doses during the residual period at Hooker will be small and are 

unlikely to reach levels that would trigger worker compensation. However, we are concerned that the 

bases for calculating these doses may not be well understood and may not be consistent with the 

physical situation that was modeled. 

NIOSH states on page 2 of its December 6, 2016, response that: 

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 
Memo – Review of NIOSH Response Paper 2 SC&A – December 23, 2016

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.

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 paraphrase the NIOSH statement, airborne concentrations decrease rapidly after the cessation of 

operations but surface concentrations do not. Therefore, use of TIB-009 to calculate ingestion doses for 

the residual period based on airborne concentrations at the end of operations is an appropriate bounding 

approach.

We remind the reader that TIB-009 estimates two equal contributions to ingestion doses: 

• Airborne particulates that fall onto the surface of a coffee cup

• Surface contamination (from airborne particulates) that is transferred from hand to mouth

Half the contamination during the residual period (ingestion via deposition into a coffee cup) will 

rapidly disappear during the residual period. Thus, while use of TIB-009 as proposed by NIOSH is 

bounding, it is inconsistent with the physical model involving rapid decrease in airborne transfer of 

particulates to a coffee cup during the residual period. As a cautionary note, it has generally been agreed 

that overly conservative bounding calculations can be used to screen out exposures that will not result in 

compensable exposures, but they are inappropriate for awarding compensation. 

On the basis of this cautionary note on screening of compensable exposures, SC&A would recommend 

that Finding 4 be closed. 

References

NIOSH 2016a. Technical Basis Document for the Hooker Electrochemical Company, DCAS-TKBS0009, Revision 03, Division of Compensation Analysis and Support, National Institute for Occupational 

Safety and Health, Cincinnati, Ohio. September 13, 2016. 

NIOSH 2016b. NIOSH Response to Sanford Cohen & Associates Review of Hooker Electrochemical 

Company TBD (DCAS-TKBS-0009 rev. 3), Division of Compensation Analysis and Support, National 

Institute for Occupational Safety and Health, Cincinnati, Ohio. December 6, 2016. 

OCAS 2004. Estimation of Ingestion Intakes, OCAS-TIB-009, Revision 00, Office of Compensation 

Analysis and Support, National Institute for Occupational Safety and Health, Cincinnati, Ohio. April 13, 

2004. 

SC&A 2016. SC&A Review of DCAS-TKBS-0009, Revision 03, for Hooker Electrochemical Company, 

SCA-TR2016-SP008, Revision 0, SC&A, Inc., Vienna, Virginia. November 21, 2016.