Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chemical Substances TLV ® Committee Lisa Brosseau, ScD, CIH Associate Professor University of Minnesota Chair, TLV ® -CS Committee.

Similar presentations


Presentation on theme: "Chemical Substances TLV ® Committee Lisa Brosseau, ScD, CIH Associate Professor University of Minnesota Chair, TLV ® -CS Committee."— Presentation transcript:

1 Chemical Substances TLV ® Committee Lisa Brosseau, ScD, CIH Associate Professor University of Minnesota Chair, TLV ® -CS Committee

2 ACGIH ® Committees Committees consist of members, who volunteer time toward developing scientific guidelines and publications –Primary goal is to serve the scientific needs of occupational hygienists –Committee expenses (travel) are supported by ACGIH ® –Time is donated by the members

3 A Short Historical Perspective 1941 TLV ® Committee Created –Committee of Technical Standards creates Subcommittee on Threshold Limits (becomes independent committee in 1944) 1946 List Published –First published list of Maximum Allowable Concentrations (MACs) for 150 chemical substances (renamed Threshold Limit Values in 1948)

4 History 1955 Written Documentation –TLV ® Committee begins to write Documentation for each TLV ® (207 completed by 1958) –Published 1st edition in 1962 (257 substances)

5 History Important Additions and Changes – Skin Notation – Carcinogens Appendix – Excursion factors – Notice of Intended Changes » TLVs ® for Physical Agents Committee – Cancer classifications defined – Operational guidelines & procedures – List of Substances & Issues Under Study

6 History More Changes – Established Biological Exposure Indices (BEI ® ) Committee – Deleted STELS for many substances – CD-ROM – Reformatted TLV ® Book to include information on TLV ® Basis - Critical Effects

7 Committee Structure Chair –Recommendations from Committee & Staff; Board appoints Vice-Chair, Subcommittee Chairs, Members –Recommended by Chair, appointed by Board Three Subcommittees, each with Chair –Dusts & Inorganics (D&I) –Hydrogen, Oxygen & Carbon Compounds (HOC) –Miscellaneous Compounds (MISCO) Staff Support (Liaison, Clerical, Literature Searching)

8 Chemical Substance Subcommittees Approximately 10 members on each Membership from academia, government, unions, industry Membership represents four key disciplines: –Industrial Hygiene –Toxicology –Occupational Medicine –Occupational Epidemiology

9 Other Subcommittees Chemical Selection –Recommendations to HOC, D&I, MISCO Membership –Recruitment, screening, recommendations Notations –Definitions, new proposals Communications –Explaining our decisions

10 Committee Structure Board of Directors Administrative Subcommittees (Membership, Chemical Selection) Steering Committee Miscellaneous Compounds Subcommittee (MISCO) Hydrogen, Oxygen, Carbon Subcommittee (HOC) Dust & Inorganics Subcommittee (D&I) Chair of TLV ® Committee Staff

11 TLV ® Development Process Under Study List Draft Doc. Committee & Board Approval NIC Committee Review & Revision External Input Adopted Value Committee Review & Revision Committee & Board Approval

12 TLVs ® Defined TLV ® more than just THE NUMBER Documentation describes: –Critical health effects –Quality of the data relied upon and areas of uncertainty –Possible sensitive subgroups –Type of TLV ® (TWA, STEL, C) and reason for selection –Notations

13 Core TLV ® Principles Focus on airborne exposures in occupational settings Utilize the threshold concept Primary users are industrial hygienists Goal is toward protection of nearly all workers Technical, economic, and analytic feasibility are NOT considered

14 The Essential Ingredients for Developing TLVs ® Published / Peer Reviewed Science + Dedicated Volunteerism + Professional Integrity & Judgment

15 Warnings NOT to be used as an index of relative toxicity NOT for estimating toxic potential of continuous, uninterrupted exposures or other extended work periods NOT as proof/disproof of existing disease NOT to evaluate or control air pollution NOT legal standards

16 Summary Prefer human over animal data Use uncertainty factors, if necessary (but no rules) Look for threshold of effects Consider irritation an important health endpoint Not concerned with levels of risk Look for the worst case health endpoint Always select an exposure level Explain the reasons for our recommendations


Download ppt "Chemical Substances TLV ® Committee Lisa Brosseau, ScD, CIH Associate Professor University of Minnesota Chair, TLV ® -CS Committee."

Similar presentations


Ads by Google