A. Introduction

Reproductive toxins are defined by the OSHA Laboratory Standard as substances that cause chromosomal damage (mutagens) and/or substances with lethal or teratogenic (malformation) effects on fetuses. Teratogens may affect the conceptus at any stage of its development, from fertilization to birth, although damage is most likely during the first 8 to 10 weeks of pregnancy. Mutagens can also affect conceptus development, or prevent fertilization entirely by damaging the egg or sperm. In addition, there are microbiological agents that can cause maternal morbidity, miscarriage, fetal death or birth defects.

Teratogens are chemical and physical agents that interfere with normal embryonic development. Teratogens differ from mutagens in that there must be a developing fetus. Reproductive toxins may produce congenital malformations or death of the fetus without inducing damage to the pregnant woman. In general, you should consider carcinogenic, mutagenic and teratogenic chemicals hazards to reproductive health. Even though OSHA has established hazardous material exposure limits, a developing fetus can suffer adverse effects at lower doses than those considered safe for adults. Thus, you must keep exposures as low as reasonably achievable to minimize reproductive health hazards.

UNC is committed to providing additional protection for the conceptus, and establish specific procedures to protect pregnant employees. Control of employee exposures will occur without economic penalty or loss of job opportunity, including, if necessary, consideration for work assignment changes, consistent with University personnel policy. Assuring protection from exposures to radiation and/or chemicals for the conceptus requires full cooperation of the employee with the Department of Environment, Health and Safety (EHS). If you wish to take advantage of this policy, contact EHS as soon as possible after determining or contemplating pregnancy, to ensure implementation of these policies.

B. Chemical and Radiological Reproductive Hazards

A thorough list of known reproductive toxins is found in Appendix 8-A to this Chapter. This list includes agents that cause fetal developmental toxicity, damage the male/female reproductive cells, or other difficulty with conception. Examples of reproductive toxins commonly found in laboratories include:

  • 1,3-Butadiene
  • Ethylene thiourea
  • Arsenic
  • Fluorouracil
  • Benzene
  • Halothane
  • Cadmium
  • Ionizing radiation
  • Carbon disulfide
  • Lead
  • Dibromochloropropane
  • Mercury compounds
  • Ethylene dibromide
  • Polychlorinated biphenols (PCBs)
  • Ethylene glycol monomethyl (and ethyl) ethers
  • Toluene
  • Ethylene oxide
  • Urethane

Please refer to Appendix 8-A for a thorough listing.

C. Microbiological Reproductive Hazards

Certain microbiological agents can cause miscarriages, fetal death and birth defects. Employees can be exposed to these agents via splashes or contact with mucous membranes, needlesticks or ingestion. The following agents are known to be reproductive hazards:

  • Cytomegalovirus (CMV). CMV is a known teratogen and congenital infection can cause mental retardation, cerebral palsy, epilepsy, vision and hearing problems especially during the first 20 weeks of fetal development.
  • Hepatitis A, B, C. Prenatal infection can cause prematurity and psychomotor retardation.
  • Human Immunodeficiency Virus (HIV). HIV can affect fertility. HIV can also be transmitted to the fetus.
  • Human Parvovirus (Fifth Disease). Prenatal infection with human parvovirus can cause fetal edema and death. Intrauterine infection may cause fetal anaemia.
  • Listeria monocytogenes. This bacterium is found in a variety of animals including mammals and birds so is of special concern to employees handling animals. Perinatal infections occur transplacentally and can result in abortion, stillbirth, meningitis, endocarditis, or septicemia.
  • Rubella virus (German measles). Congenital rubella syndrome (CRS) may occur in infants born to women who had rubella during the first trimester. This can lead to fetal death, spontaneous abortions, congenital malformations of the eyes, ears and heart, mental retardation and/or poor childhood growth. The risk decreases with fetal development.
  • Toxoplasma gondii (toxoplasmosis). Congenital cases can result in abortion and stillbirth. Live births may result in central nervous system disorders, hydrocephaly, or mental retardation. Transplacental infection is least likely during the first trimester, but these cases are the most severe. Cats can carry this disease and employees conducting experiments with cats may need to take additional precautions.
  • Varicella virus (Chicken Pox). Congenital infection can cause limb atrophy, microcephaly, cortical atrophy, motor, sensory and eye problems. Infection during the first trimester can cause miscarriage, muscular atrophy, clubbed foot, CNS disease and cataracts in the fetus.

This list is not all-inclusive and EHS will evaluate work exposures to all infectious materials once an employee has declared her pregnancy.

D. Declared Pregnancy

If you wish the University to be involved in protecting your fetus, and exposures to the fetus kept below the 500 millirems limit if you are a radiation worker, you must declare your actual, suspected, or planned pregnancy to your supervisor and EHS in writing, or by e-mail. The University’s responsibility for conceptus protection begins only after receipt of this notice of pregnancy, or intended pregnancy, to your supervisor and EHS. The involvement of supervisors is an essential part of the University’s safety management. EHS urges every potentially pregnant employee to consider her supervisor’s safety responsibilities and freely involve the supervisor in all work-related situations.

E. Conceptus Protection Program

Following written or e-mail notice of pregnancy or intended pregnancy to the EHS Director, Biological Safety Officer, Chemical Hygiene Officer, or Radiation Safety Officer (RSO), EHS institutes a Conceptus Protection Program (CPP). The CPP consists of three elements.

1. Confidential Conferences

Conferences include the employee, her supervisor, and EHS specialists. The employee is provided a copy of this policy and other pertinent literature on protecting pregnant employees from chemical, biological and radiological exposures. Following the conference, EHS sends an assessment report to the employee and supervisor relating findings and recommendations of work involving hazardous materials. In some cases, adjustments should be made in work responsibilities, if practicable, to avoid higher risk operations.

An additional interview is available with an occupational health nurse or physician at the University Employee Occupational Health Clinic. This interview allows the employee to express concerns and to ask questions about reproductive and developmental health. A review of an occupational and reproductive health questionnaire facilitates collection of employee-specific information, assists the employee in formulating concerns about chemical and physical hazards, and provides structure and focus for the interview. A preconception planning stage is also available. Obstetric specialists are available for consultation or referral for any specific concerns.

EHS understands that employees may choose to maintain their pregnancy status as personally confidential for a time. Any employee may still receive safety information about pregnancy and chemical, biological, and radiological exposures at any time from EHS without declaring her pregnancy status.

2. EHS Review of Laboratory Safety

EHS will conduct a review of the laboratory or worksite safety plan to ensure that it provides appropriate guidance to protect workers and prevent occupational exposures. EHS inspects the work place to ensure that adequate engineering controls, such as laboratory hoods, are provided, and that safe handling procedures and the use of personal protective equipment are in place. Employees have the responsibility of adhering to University safety procedures described in the Laboratory (or worksite) Safety Plan, the Health and Safety Manual, Laboratory Safety Manual, Biological Safety Manual and the Radiation Safety Manual.

3. Radiation and Chemical Exposure Monitoring

EHS will monitor employee exposures levels for radiation and any chemicals of concern, especially those with evidence of reproductive toxicity. The employee and principal investigator, or supervisor, shall receive a copy of the monitoring report. The goal is to keep all exposures as low as reasonably achievable.

EHS performs the personnel radiation monitoring through the Radiation Safety section. EHS assigns the radiation employee a monthly radiation badge and/or places her on a monthly bioassay program.

F. Action Levels

1. Radiation Exposures

Current investigational radiation dose limits for declared pregnant or planned pregnancy employees will direct the RSO in evaluating reported doses. The North Carolina Regulations for Protection Against Radiation has established a radiation dose limit of 500 millirems for the conceptus during the entire gestation period.

Action Level I:

Employees with exposures greater than 30 millirems in a month. The RSO or designee shall send a written description of the dose report statistics, including the dose history for the previous two monitoring periods, to the person involved with a copy to the Authorized User. EHS asks the individual and their supervisor to review his or her radiation safety procedures and work habits in an effort to maintain all doses as low as reasonably achievable. Health physics reviews and consultation are available.

Action Level II:

Greater than 40 millirems in a month. The RSO shall conduct a direct investigation of the situation, including an interview with the person involved. The RSO prepares a written investigation report, including trends over the past one year (as available) for that person. The RSO provides a copy of the report to the employee for review and signature. Conclusions drawn from the investigation provide a basis for confirming or modifying the dose and for establishing corrective actions to undertake.

When the occupational radiation dose of a declared radiation employee exceeds 50 millirems in a month since declaration, the employee may request:

  • Maternity leave (for those employees actually pregnant)
  • Other paid leave
  • Leave without pay
  • Reassignment within their work unit
  • Transfer

The supervisor should respond to requests in accordance with Human Resources personnel policies.

EHS and the Radiation Protection Section of the NC Department of Environment and Natural Resources accept doses reported from personnel monitoring badges generally as an uncorrected guide to any conceptus dose. If personnel monitoring results indicate the possibility of a conceptus dose in excess of the 500-millirem limit, a special investigation will result. The investigation will take into full consideration the type and energy of radiation involved, protective shielding that might have mitigated conceptus dose, and shielding afforded by the mother’s body. The employee and EHS will discuss the investigation results, and a written report provided.

2. Chemical Exposures

As stated earlier, the goal is to keep all exposures to both radiation and chemicals as low as reasonably achievable. The actions taken in response to a measured chemical exposure depend on the specific circumstances and chemicals involved. However, as a general rule, if any exposure measurements exceed 10% of the threshold limit value (TLV) or permissible exposure limit (PEL) action will be taken to prevent further exposure by instituting engineering controls, improved work practices, personal protective equipment (PPE), or job reassignment.

3. Microbiological Exposures

There are no action levels for microbiological agents. Many of the agents listed above can be safely handled at Biosafety Level 2 practices and containment (culturing HIV requires Biosafety Level 3 practices). Biosafety Level 2 practices include wearing gloves, labcoats and eye protection, conducting any aerosol generating procedures inside of a biological safety cabinet, decontamination of surfaces, frequent handwashing, and no eating, drinking, smoking or handling contacts in areas where infectious materials are handled. Please refer to the UNC Biological Safety Manual for more detailed information. These practices are required to protect the employee; however, some procedures conducted in the laboratory may be higher risk for pregnant employees and should be evaluated by EHS. In addition, the risks to the fetus from exposure to these pathogens may warrant restriction from use during a pregnancy. EHS in consultation with the employee and their supervisor will determine when restriction or additional personal protective equipment is necessary.