Blockson Chemical Company (Building 55 and related activities)

(Site Profile/Docket Number 013)

Location: Joliet, Illinois

Also Known As: Blockson Chemical Group, Olin, Olin Mathieson

Special Exposure Cohort Petition Information

The Special Exposure Cohort (SEC) is a unique category of employees established by the Act (42 CFR Part 83). Claims compensated under the SEC do not have to go through the dose reconstruction process. To qualify for compensation under the SEC, a covered employee must meet specific requirements (e.g., must have at least one of 22 “specified cancers,” and have worked for a specified time period at one of the SEC sites). Classes of employees and work sites can be considered for addition to the SEC through a NIOSH petition process. More information about the Special Exposure Cohort can be found on our Frequently Asked Questions page.

Open/Active SEC Petitions

To date, there are no open/active SEC petitions from Blockson Chemical Company – Building 55.

Class(es) Added to the SEC

  • All Atomic Weapons Employer employees who worked at the Blockson Chemical Company in Joliet, Illinois from March 1, 1951 to June 30, 1960, 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 included in the Special Exposure Cohort.

    Note: This class was established from Petition 58.

Class(es) Not Added to the SEC

  • All employees who worked in any area at the Blockson Chemical Co. site in Joliet, Illinois, during the period from July 1, 1960, through December 31, 1991.

    Note: This class was established from Petition 225.

Petitions Qualified for Evaluation

Below is a list of the petitions that qualified for evaluation. Select a petition on the list to view the table for that particular petition.

Worker Outreach Activities

Based on a recommendation from the Advisory Board to provide workers and site experts with opportunities to participate in developing the technical documents used in dose reconstruction, NIOSH established a Worker Outreach Program.

At Worker Outreach Meetings, current and former DOE and AWE employees have opportunities to obtain information about Site Profiles, Technical Basis Documents, and Technical Information Bulletins, and to provide information for consideration and possible use in dose reconstruction. This process is valuable to ensure that the technical documents used in dose reconstruction contain correct and useful information.

Worker Outreach Activities for the Blockson Chemical Company – Building 55:

  • September 12, 2007
    Meeting with former Blockson/Olin Chemical Company workers and survivors of former workers in Joliet, IllinoisJoliet Municipal Building
    150 West Jefferson
    Joliet, Illinois
    Final Minutes [103 KB (32 pages)]
  • January 24-25, 2007
    Meeting with former workers from Blockson Chemical Company, Joliet, IllinoisJoliet Municipal Building
    150 West Jefferson
    Joliet, Illinois
    7:00 p.m.

    Note: Former workers are welcome to attend either or both meetings and we encourage you to invite other workers who may have knowledge about the former Blockson Chemical Company. Please note that these meetings are not being held to discuss individual claims or concerns about the EEOICPA program. The meetings will be transcribed by a court reporter and the transcript will be made available to the public.
    Transcript from January 24, 2007 [3.9 MB (152 pages)]
    Minutes from January 25, 2007 [156 KB (35 pages)]

Advisory Board Work Group on Blockson Chemical Company

This Work Group is responsible reviewing the SEC petition from the Blockson Chemical Company petitioners, reviewing the NIOSH Evaluation Report of the petition, considering issues that may be raised by the Board’s contractor (SC&A) concerning the NIOSH Evaluation Report, and for assisting NIOSH and SC&A in the resolution of such issues. The Work Group may recommend to the Board, changes in the Site Profile as appropriate. The Work Group should strive to develop a recommendation to the Board on whether a class should be added to the SEC.

Work Group Members:

  • Genevieve S. Roessler, Ph.D. (Chair)

  • Bradley P. Clawson

  • Loretta R. Valerio

Meeting Information:

Pre-Decisional Document Policy

Please note that as part of the procedures and processes of the Advisory Board’s Work Groups, several kinds of pre-decisional documents may be developed. These pre-decisional documents, such as white papers, matrices, working drafts, etc., are distributed among Work Group members as research and background tools to facilitate discussion and deliberation. Although discussion during a public meeting may cover pre-decisional documents, these documents often are not further revised or finalized, and thus do not reflect the final determination or evaluation of the Advisory Board and its Work Groups. Additionally, some pre-decisional documents not otherwise posted on the website may contain sensitive information, which would require an interested party to obtain such documents by filing a Freedom of Information Act (FOIA) request with the CDC/ATSDR FOIA office at

Technical Documents

If the energy employee’s personal radiation information is incomplete, NIOSH will use other sources to estimate the radiation dose. This may involve using technical documents called Site Profiles, Technical Basis Documents, and Technical Information Bulletins.

Technical Basis Documents

Advisory Board and NIOSH Discussions on Blockson Chemical Company

The Blockson Chemical Company discussion papers listed below are working documents prepared by NIOSH or its contractor for use in discussions with the Advisory Board on Radiation and Worker Health or its Working Groups or Subcommittees. Draft, preliminary, interim, and white paper documents are not final NIOSH or Advisory Board (or their technical support and review contractors) positions unless specifically marked as such. These documents represent preliminary positions taken on technical issues prepared by NIOSH or its contractor.

The discussion papers have been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

Program Evaluation Plans (PEPs) and Program Evaluation Reports (PERs)

NIOSH is committed to applying the best available science in dose reconstructions. In keeping with this commitment, completed cases with probabilities of causation less than 50% are reviewed as relevant new information becomes available. The results of these reviews are described in a Program Evaluation Report (PER). The PER details the effect, if any, of the new information on the completed dose reconstruction. If it appears that the new information may result in an increase in dose for a completed dose reconstruction with a probability of causation of less than 50%, NIOSH is committed to working with the Department of Labor to reopen and rework the dose reconstruction, as appropriate. A Program Evaluation Plan (PEP) describes plans for evaluating specific program details or issues.

  • DCAS-PER-060: Blockson Chemical Company [16 KB 2 pages)]
    April 27, 2015

    About this Document: Determines the effect of the revised Technical Basis Document for the Blockson Chemical Company on previously completed claims.

    Summary: Out of the potentially effected claims, one resulted in a higher internal dose. A full dose estimate was completed using TBD revision 4, as well as all applicable approved dose reconstruction methods. The probability of causation remained below 45% for this claim. No claims need to be returned to NIOSH. NIOSH will provide DOL with the list of all the claims evaluated under this PER.

  • DCAS-PER-036 Rev-0: Program Evaluation Report: Blockson TBD Revision [18 KB (3 pages)]
    April 5, 2012

    About this Document: New document to determine which previously completed claims require evaluation for the affect of revising the Blockson TBD.

    Summary: Revision 3 of the Blockson Chemical Company Technical Basis Document (DCAS-TKBS-0002) was issued on 12/20/2010. The previous version (revision 2) was issued on 11/21/2007. PER-020, issued on 7/31/2007, evaluated the effect of all changes that were made to the Blockson Chemical Company Technical Basis Document (TBD) prior to that date. This resulted in a request to DOL for the return of all previously completed Blockson claims that had a probability of causation of less than 50%. Once returned, a new dose reconstruction was completed for each using the version of the TBD current at that time. Revision 1 of the TBD was current when PER-020 was issued. However, revision 2 was issued a short time later on 11/21/2007 prior to any claims being completed using revision 1. Therefore, this PER only considered the changes that were made between revision 2 and revision 3. This information is summarized below:

    • Revision 0 all claims completed using revision 0 were requested returned (PER-020).
    • Revision 1 No claims were completed using this revision
    • Revision 2 The subject of this PER
    • Revision 3 The current version of the TBD
  • OCAS-PER-0020 Rev-00: Program Evaluation Report: Blockson TBD Revision [14 KB (1 page)]
    July 31, 2007

    About this Document: New document to determine which previously completed claims require evaluation for the effect of revising the Blockson TBD.

    Summary: It is not possible to determine the magnitude of the change to dose without a new dose estimate. Since (as of issuance of this PER) no Blockson Chemical Company claims have yet been completed with the newest revision to the TBD, NIOSH is requesting that all Blockson Chemical Company claims with a Probability of Causation less than 50% be returned for a new estimate. A list of the entire population of the ninety-one potentially affected claims is attached. A new dose reconstruction will be completed for each of the claims using the latest revision to the Blockson TBD.

Public Comments on Blockson Chemical Company Documents

How to Submit Comments

Comments on Blockson Chemical Company
Documents can be submitted to the NIOSH Docket Officer electronically by email at or printed comments can be mailed to:

NIOSH Docket Office
Robert A. Taft Laboratories, MS-C34
1090 Tusculum Avenue
Cincinnati, OH 45226
Please include the Site Profile/Docket Number (013) on all comments.

Comments Received

Miscellaneous Documents Regarding Blockson Chemical Company

Document Archive for Blockson Chemical Company