At CIH Enterprises, Inc. we have team members who are board certified safety, medical, and health professionals. Team members have received certification through the American Industrial Hygiene Association (AIHA) and the American Conference of Governmental Industrial Hygienist (ACGIH) to develop and execute biological monitoring programs. Our “one stop shop” involves the customized written program, consent forms, legal review through companies’ procedures, and beginning to end execution. Our CIH Enterprises, Inc. team in 2018 started taking occupational biological and genetic samples from personnel working in occupational environments with consent of the employees tested. Should you wish to discuss this with our team members please do not hesitate to reach out to us at 785.493.1002 or www.cihent.com.

To provide a quick synopsis of the biological exposure index, its use in assessing chemical exposures in the workplace please review the following.

BIOLOGICAL MONITORING

Biological monitoring is an assessment of overall systemic exposure to chemicals by measurement of the chemicals or their metabolites in blood, urine or breath. Numerous toxicological entities review chemical which includes recommendations to change a number or the current BEIs and to add new BEIs to the WorkSafe list of BEIs as published in such documents as the Special Guide Workplace Exposure Standards and Biological Exposure Indices, 9th Edition (WorkSafe, 2017). This review considers BEIs from other jurisdictions/organizations around the world and their justification for setting those values. Note that only BEIs from other jurisdictions/organizations which have documented their rationale for setting the BEI have been considered for this review. This includes BEIs from the: – American Conference of Governmental Industrial Hygienists (ACGIH®) – European Scientific Committee on Occupational Exposure Limits (SCOEL) – Deutsche Forschungsgemeinschaft (DFG) of Germany – UK Health and Safety Executive (HSE). All substances or their metabolites included in these organizations can be analyzed through CIH Enterprises, Inc. team of certified professional and audit laboratory team-members.

By using physiologically based pharmacokinetic (PBPK) modeling coupled with Monte Carlo simulation, the interindividual variability in the concentrations of chemicals in a worker’s exhaled breath and urine were estimated and compared with existing biological exposure indices (BEIs). The PBPK model simulated an exposure regimen similar to a typical workday, while exposure concentrations were set to equal the ambient threshold limit values (TLV®s) of six industrial solvents (benzene, chloroform, carbon tetrachloride, methylene chloride, methyl chloroform, and trichloroethylene). Due to extensive research and evolution of technology our team believes that information presented in this research studies may provide a new approach for administrative decisions establishing BEIs and allow uniform application of biological monitoring among different chemicals.

Human exposure to chemicals in the workplace has traditionally been assessed by determining the concentration of an airborne chemical in the workroom air. More recently, biological monitoring has been used to assess worker uptake of chemicals by all routes of exposure. Both approaches for the assessment of exposure and uptake are complementary. This relationship is examined, along with the advantages and limitations of using biological monitoring.

The concept of the biological exposure index (BEI), developed by the American Conference of Governmental Industrial Hygienists (ACGIH), and information on the intended use and interpretation of BEIs are described.

BIOLOGICAL EXPOSURE INDEX (BEI)

The American Conference of Governmental Industrial Hygienists (ACGIH) publishes a yearly updated list of approximately 30 chemicals with BEIs.

Biological exposure indices (BEI) are values used for guidance to assess biological monitoring results. With respect to chemical exposure, biological monitoring is the measurement of the concentration of a chemical marker in a human biological media that indicates exposure. This is most easily and unobtrusively done with certain humanfluids and tissues such as, blood, urine, faeces, saliva, earwax, tears, sputum, sweat, expired air, nails, hair, skin and sometimes fat. Sampling is difficult if internal organs must be sampled. The markers measured may include the actual chemical, a metabolite or degradation product, and biochemical reaction product or response (e.g., antigen, enzyme, antibody). The detection and concentration of a marker is indicative of exposure.

The BEI concept, like the TLV, is based upon each chemical having a reasonably safe level of exposure below which significant illness, injury, or discomfort will seldom happen. There is no fine line between hazardous and non-hazardous exposures based upon BEIs. The biological monitoring should be considered complementary to workplace air monitoring because it can confirm and verify the results of the air monitoring. The BEIs are based on human exposure data, which shows a relationship between intensity of exposure and the determinant biological levels or between the determinant biological levels and human health effects.

The determinant is the actual substance being analyzed and the body fluid in which it is measured, e.g. methemoglobin in blood for aniline, muconic acid in urine for benzene. Sampling can be carried out before, during, or after a shift or work week. Sampling time details are also defined. For example, “prior to shift” means 16 hours after exposure ceases, “during shift” is anytime after 2 hours exposure, “end of shift” is immediately after exposure ceases, “end of work week” is after 4 or 5 consecutive work days of exposure, and “discretionary” means any time.

BEI values are usually expressed in units that are based on the type of sample being measured. For example: the BEIs from urine samples are based upon milligrams or micrometers per gram of creatinine (C4H7ON3), the BEIs from blood samples are based upon a percent of hemoglobin, and the BEIs from breath samples are in ppm of exhaled air.

Reach out to our team a CIH Enterprises, Inc. to protect the inhalation, dermal, and biological uptake of occupational workers at 785.493.1002 or www.cihent.com.

GLOSSARY OF RELEVANT TERMS

ACGIH® : The American Conference of Governmental Industrial Hygienists (ACGIH®) is a 501(c)(3) charitable scientific organization, established in 1938, that advances occupational and environmental health. Examples of this include their annual edition of the TLVs® and BEIs® book and Guide to Occupational Exposure Values.

BEI : Biological Exposure Index.

BLW : Biologische Leit-Werte is a German biological guidance value and is the amount of a chemical substance or its metabolites which serves as an indicator for necessary protective measures. BLW values are derived for carcinogens and for substances without sufficient data.

BOELV : Binding occupational exposure limit value. The European Union requires all member states to set this value (or lower) as a BEI.

DFG : Deutsche Forschungsgemeinschaft (German Research Foundation), the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Federal Republic of Germany. The science-based MAK values are recommended to the German Minister of Labour and Social Affairs for possible adoption under the German Hazardous Substances Ordinance.

HSE : The UK Health and Safety Executive.

Metabolite : The intermediates and products of metabolism of substances.

mg : Milligram or one thousandth of a gram.

mg/m3 : Milligrams of substance per cubic metre of air.

mg/kg : Milligrams of substance per kilogram.

ml : Millilitre, or thousandth of a litre.

NIOSH : The National Institute for Occupational Safety and Health (NIOSH) is the United States federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the Centers for Disease Control and Prevention (CDC) within the U.S. Department of Health and Human Services.

NOAEL : No observable adverse effects level.

ppm : Parts per million parts of air.

SCOEL : The Scientific Committee on Occupational Exposure Limits is a committee of the European Commission, established in 1995 to advise on occupational health limits for chemicals in the workplace within the framework of Directive 98/24/EC, the chemical agents directive, and Directive 90/394/EEC, the carcinogens at work directive.

SMR : Standardized Mortality Ratio (SMR) is a ratio between the observed number of deaths in a study population and the number of deaths would be expected, based on the age- and sex-specific rates in a standard population and the age and sex distribution of the study population.

TLV® : Threshold Limit Value (see TLV-TWA below). An ACGIH® term.

TLV-TWA : TLV® – Time-Weighted Average; the TWA concentration for a conventional 8-hour workday and a 40-hour workweek, to which it is believed that nearly all workers may be repeatedly exposed to, day after day, for a working lifetime without adverse effect. An ACGIH® term.

WES : Workplace Exposure Standard – WESs are values that refer to the airborne concentration of substances, at which it is believed that nearly all workers can be repeatedly exposed to, day after day, without coming to harm. The values are normally calculated on work schedules of five shifts of eight hours duration over a 40 hour week. A WorkSafe term.

WES-TWA : The average airborne concentration of a substance calculated over an eight-hour working day. A WorkSafe term.