Hazardous materials are a fact of life in the military. Many job specialties within the military involve working with potentially harmful chemicals, such as fuels, solvents, pesticides, heavy metals, certain medical drugs and gases, and lead. During training scenarios, service members are subjected to tear gas; and if stationed overseas, service members may be exposed to pathogens or biological/chemical warfare agents. In addition, military members are required to receive certain immunizations for overseas travel. Many of these hazardous materials and immunizations can potentially be passed through breastmilk to the nursing infant. This page will give you an overview of the potential risks associated with HAZMAT exposure and immunization requirements in the military, how to weigh those risks, and precautions you can take to minimize your exposure. However, this is not a replacement for speaking with your Occupational Health representative or Medical.
Weighing the Risks
Exposure levels to HAZMAT at military worksites are monitored and kept within established safety limits for adults. However, military mothers in certain occupations are exposed to higher levels than the general population, and there are not many studies measuring the levels of potentially harmful chemicals in the breastmilk of active-duty women. Some of these chemicals do concentrate in breastmilk and may exceed safe does for infants, even though they are within safe levels for you. Further, a few studies do show that high occupational exposures can have adverse health effects on breastfed infants (4,6,7) .
But, this does not meant that you cannot safely breastfeed while continuing your job in the military. It is important to weigh the risk of exposure and balance it against the substantial benefits of breastfeeding (and the well-known hazards of formula). When determining what the risk of exposure is for a certain hazardous material, it is important to look at the following: chemical characteristics, how the toxin transfers into milk (does it concentrate in fat, have high or low acidity, what is the protein binding and molecular mass, what is the half-life) (4,5,7). In addition your age, number of previously breastfed children can affect absorption of chemicals and toxins. Unlike medications, many toxic substances stay in the body long-term and oftentimes most of it is passed on to the fetus while still pregnant. Furthermore, due to long-term accumulation, first-born breastfed children are potentially exposed to more chemicals than subsequently breast-fed children (1,3).
There are a number of other questions to consider when weighing the risks of exposure to HAZMAT while breastfeeding:
- What is the probability of exposure to toxic substances in your workplace?
- What is the level of exposure (is it daily, once a week, once a quarter)?
- What is the route of exposure (ingestion, inhalation, topical)?
- What is the effect of the substance on your baby?
- How old is your baby?
- How often do you pump or breastfeed?
- Can you be reassigned to other job duties?
- Is there protective gear that you can wear to reduce exposure?
- What is your comfort level of exposure before you will decide to wean versus the known benefits of breastfeeding?
JP-8, Lead and Tear Gas….Oh My!
JP-8, Lead and Tear Gas are the three main hazardous materials that many military personnel are exposed to on a regular basis, and the three for which there is some published information available as to the safety of exposure while breastfeeding and/or expressing breastmilk. JP-8, the mainstay of aviation fuel in the military services, is composed of primarily hydrocarbons (kerosene) as well as benzene and toluene, all of which are fat-loving (lipophilic) and are known to cross into breastmilk (which is high in fat). In most cases flight line personnel, mechanics, fuel-handlers, and aircrew face exposure via inhalation of raw fuel vapors and/or exhaust, or topical exposure via splashed fuel on the skin. JP-8 exhaust inhalation is similar to exhaust levels from living near freeways/highways in a major city, and research to date shows little risk of breastmilk contamination from this type of exposure (8). Topical exposure from splashed fuel is minor if washed off quickly, and the main symptom would be skin irritation. Little is known about whether any JP-8 would cross into breastmilk via skin exposure. Exposure to raw fuel vapors, especially in enclosed spaces such as fuel cells may cause headaches, dizziness, respiratory distress, and possible brain damage with high, long-term and repeated exposure (5). However there has been no research to date on the transfer into breastmilk from this type of exposure. Erring on the side of caution would be prudent for fuel-cell technicians.
Lead exposure is complex and potentially problematic. Lead is found in everything from ammunition to the paint used on equipment, vehicles, and ships. Lead exposure is often via inhalation or ingestion where it is enters the bloodstream and accumulates in the bones. During lactation lead is released from the bones and transported easily into breastmilk due to it’s chemical similarity to calcium. Research to date is mixed as to the level of lead transferred from mother to baby via breastmilk, and there is NO known safe dose of lead that is acceptable for infants (5,6,7). Exposure to lead results in anemia, brain damage and developmental delays. Individuals working in certain MOS’s requiring daily, high-level exposure to lead (chipping lead paint, working in an enclosed, indoor armory) would need to wean in order to remove any possible contamination of their breastmilk (2,5,6). However, individuals who have infrequent exposure to lead (such as annual firearm quals or training in the field) can so do safely if they follow the precautions listed below. If there is any doubt about your lead exposure a simple blood test can determine your levels. Speak with your Occupational Health representative about your options.
Tear gas or 2-chlorobenzalmalononitrile, is used primarily for training purposes in the military and police forces. Of the three hazardous materials listed, it is the most often asked about and the least likely to cause any problems with breastfeeding or pumped breastmilk. Tear gas is both inhaled and topically absorbed through the skin, and while toxic at high doses, at the levels used in training, it’s main symptoms cause nasal discharge, difficulty breathing, pain and tearing of the eyes, nausea and vomiting, and skin irritation. It is transient and disperses quickly with fresh air. The molecules that compose tear gas are too big to pass into breastmilk so there is no danger to expressing breastmilk after exposure. There is no need to pump and dump after exposure since the chemical does not cross into breastmilk (8). Contamination from close contact can occur, but simple precautions such as taking a shower to rinse the chemical off of the skin before picking up or holding your infant suffice. Also laundering the uniform worn during the exposure separately from other clothes lessens the risk of exposure to other family members.
Immunizations such as Anthrax, Yellow Fever, Smallpox, and Typhoid (as well as Malaria prophylaxis) are required for military personnel, especially if you will be traveling overseas for a deployment or to a new duty station. While many routine vaccinations such as influenza, MMR, TDaP, Varicella, etc are considered safe to receive when breastfeeding, there are a few that are not. Without getting into a detailed explanation of how vaccinations work, suffice to say that vaccinations using dead particles of the bacteria or virus in question are generally considered safe when breastfeeding, as opposed to vaccinations that use live, weakened (attenuated) particles. As with any decision regarding medications, immunizations or exposure to chemicals, you must weigh the risks of contracting the (possibly fatal) disease in question versus the risks of not breastfeeding your infant. Here is information on the most commonly given immunizations given to military personnel being deployed to certain areas of operation (5,9,10) :
- Anthrax: L3 – No Data, Probably Compatible. Injectable form (made from dead bacteria particles). The protein fragments are too large to pass into breastmilk and would not be bioavailable to the infant. According to the CDC it is NOT contraindicated in breastfeeding mothers, and should be given when high probability of occupational exposure exists. Normal side-effects include redness and swelling at injection site, occasionally flu-like symptoms present in fewer than 0.2% of recipients.
- Permethrin-treated uniforms: L2 – Limited Data, Probably Compatible. Topical absorption, less than 2%. Permethrin is rapidly metabolized to an inactive state and excreted in the urine, some may be sequestered in fat tissue. Amounts in breastmilk are far lower than the acceptable daily intake (ADI) and no adverse reactions have been reported in breastfeeding infants.
- Doxycycline: L3 – Limited Data, Probably Compatible. A long-half life tetracycline antibiotic. Secreted into breastmilk with peak levels 2-4 hours after ingestion. Tetracycline antibiotics bind to teeth causing discoloration. Prolonged use may alter gastrointestinal flora. Short-term use (3-4weeks) is considered compatible with breastfeeding. Relative infant does is 4.2-13.3%. No harmful effects have been reported in breastfeeding infants.
- Mefloquine: L2 – Limited Data, Probably Compatible. Antimalarial drug with long half-life. Mefloquine is secreted in small concentrations (3%) of maternal dose into breastmilk. Relative infant dose is 0.1-0.2%, not enough to protect against malaria. No harmful reactions have been reported in breastfeeding infants.
- Typhoid: L3 – No Data, Probably Compatible. Injectable form (made from dead virus particles) is preferable to the live vaccine. Live vaccine is only suggested when high probability of exposure is present. No studies on safety of live vaccine. General vaccine reaction (malaise, headache, soreness at injection site) is expected.
- Yellow Fever: L4 – Limited Data, Possibly Hazardous. It is a LIVE vaccine and probable transmission can (and has occurred) with breastfeeding infants. Infants infected via breastmilk from yellow fever vaccines showed the antigen in their cerebrospinal fluid (CSF), and had symptoms of yellow fever encephalitis (seizures, fever, irritability, vomiting). According to the CDC, vaccination of breastfeeding mothers with infants 0-5 months should be avoided, if that is not possible then the benefit of the vaccine outweighs the risk and the vaccine should be given. Studies have shown that the vaccine virus is NO LONGER present in the mothers bloodstream 10-13 days AFTER vaccination (and therefore would not be in breastmilk either).
Precautions to Take
While the military is responsible for training and protection regarding hazardous materials in your workplace; you are equally responsible for learning about those hazardous materials, using personal protective equipment, and following proper work practices. Here are some steps you can take to ensure you and your baby’s safety:
- Store chemicals in sealed containers when they are not in use.
- Wash hands after contact with hazardous substances and before eating, drinking, or smoking.
- Avoid skin contact with chemicals.
- If chemicals contact the skin, follow the directions for washing in the material safety data sheet (MSDS). Military facilities are required to have copies of MSDSs for all hazardous materials used in their workplaces.
- Review all MSDSs to become familiar with any reproductive hazards used in your workplace. If you are concerned about reproductive hazards in the workplace, consult your Occupational Health department or healthcare provider.
- Participate in all safety and health education, training, and monitoring programs offered by your command.
- Learn about proper work practices and engineering controls (such as improved ventilation).
- Use personal protective equipment (gloves, respirators, and personal protective clothing) to reduce exposures to workplace hazards.
- Follow your command’s safety and health work practices and procedures to prevent exposures to reproductive hazards.
- Prevent home contamination with the following steps:
- Change out of contaminated clothing and wash with soap and water before going home.
- Store street clothes in a separate area of the workplace to prevent contamination.
- Wash work clothing separately from other laundry (at work if possible).
- Avoid bringing contaminated clothing or other objects home. If work clothes must be brought home, transport them in a sealed plastic bag.
Hazardous chemicals and immunizations are not to be taken lightly, nor is your baby’s health. If your job depends on you working in an environment that will put your baby in danger of exposure to hazardous materials, or you must be sent overseas and need required immunizations to do so, then you certainly have every right to decide NOT to take any risks and make the decision to wean your baby. Just be sure to check out all the facts regarding the toxic chemical(s) or vaccinations in question, and look at all your options before making any permanent decisions. If you have specific questions regarding exposure to chemicals, immunizations or toxins at your command you can visit the Infant Risk Center or call them at (806) 352-2519 for further information. You can also look up specific information regarding hazardous materials exposure via HAZ-MAP and the ATSRD as well as various military-only databases.
1. Condon, M. (2005). Breast is Best, but it Could Be Better: What is in Breast Milk That Should Not Be? Pediatric nursing, 31(4), 333.
2. Czarnecki, Fabrice. (2003). The Pregnant Officer. Clinics in Occupational and Environmental Medicine, 3(3), 641-648.
3. Fisher, J., Mahle, D., Bankston, L., Greene, R., & Gearhart, J. (1997). Lactational transfer of volatile chemicals in breast milk. American Industrial Hygiene Association Journal, 58(6), 425.
4. Giroux, D., Lapointe, G., & Baril, M. (1992). Toxicological index and the presence in the workplace of chemical hazards for workers who breast-feed infants. Am Ind Hyg Assoc J, 53(7), 471-474.
5. Hale, T. W. (2012). Medications and mothers’ milk (Fifteenth ed.). Amarillo, TX: Hale Publishing.
6. Navy Environmental Health Center, N. (2008). Reproductive and Developmental Hazards: A Guide for Occupational Health Professionals. Norfolk, VA: Navy Environmental Health Center.
7. Schaefer, C. (2007). Drugs during pregnancy and lactation : Treatment options and risk assessment (2nd ed.). Amsterdam ; New York: Elsevier.
8. Personal communication with Dr. Hale (author of Medications and Mother’s Milk). 2011.
9. CDC, Traveler’s Health Advisory, Special Considerations for US Military Deployments http://wwwnc.cdc.gov/travel/yellowbook/2014/chapter-8-advising-travelers-with-specific-needs/special-considerations-for-us-military-deployments
10. Defense Health Agency, Immunization Healthcare Branch www.vaccines.mil/vaccines