Health effects of 1,3-DNB and 1,3,5-TNB
Contents
Introduction
1,3-Dinitrobenzene (1,3-DNB) and 1,3,5-trinitrobenzene (1,3,5-TNB) are synthetic substances that are used in explosives. In making 1,3,5-TNB, 1,3-DNB is often made first. Both 1,3-DNB and 1,3,5-TNB are formed as by-products when another explosive, trinitrotoluene (TNT), is made. 1,3-DNB is also used to make certain dyes, as an intermediate in the synthesis of organic chemicals, and in the plastics manufacturing industry. 1,3,5-TNB is used in making rubber. Other names for 1,3-DNB include m-dinitrobenzene, 1,3-dinitrobenzol, 2,4-dinitrobenzene, dinitrobenzene, and m-DNB. Other names for 1,3,5-TNB include benzite, s-trinitrobenzene, sym-trinitrobenzene, symmetric trinitrobenzene, syn-trinitrobenzene, and TNB. Both 1,3-DNB and 1,3,5-TNB are yellow, crystal-like solids at room temperature. They may exist in the air in very small amounts as a dust or a vapor and can dissolve in certain liquids. If either compound is put under very high heat, it will explode. These compounds have no odor or taste. In this profile, 1,3-DNB and 1,3,5-TNB are discussed together because they have very similar structures. Since the two compounds are similar in structure, their toxic effects may not be very different. (Health effects of 1,3-DNB and 1,3,5-TNB)
Pathways for 1,3-DNB and 1,3,5-TNB in the environment
Waste discharges from Army ammunition plants or other chemical manufacturers are the primary sources for the releases of both compounds to air, water (Hydrologic cycle), and soil. They can also enter the environment from their use as explosives and from spills or improper disposal. It is unlikely that either compound would normally be found in the air. However, under some industrial use conditions, some 1,3-DNB and 1,3,5-TNB may enter the air in the form of dust. We have very little information about what happens to 1,3-DNB and 1,3,5-TNB in the air. The small amounts of 1,3,5-TNB that may enter the air are likely to break down very slowly. It might persist for many years in the air. 1,3-DNB is also likely to break down in the air; however, we do not know how long this would take. Both compounds are slightly soluble in water. 1,3-DNB evaporates slowly from water; 1,3,5-TNB does not evaporate from water. Neither compound sticks strongly to soil; therefore, both can move through soil into groundwater. 1,3-DNB breaks down slowly in water and soil. It stays for days to months in water. Although 1,3,5-TNB probably breaks down in water and soil, we do not know how long this takes. Neither compound is likely to build up in fish or humans.
Exposure to 1,3-DNB and 1,3,5-TNB
Waste discharges from Army ammunition plants or other chemical manufacturers are the primary sources for the releases of both compounds to air, water, and soil. They can also enter the environment from their use as explosives and from spills or improper disposal. It is unlikely that either compound would normally be found in the air. However, under some industrial use conditions, some 1,3-DNB and 1,3,5-TNB may enter the air in the form of dust. We have very little information about what happens to 1,3-DNB and 1,3,5-TNB in the air. The small amounts of 1,3,5-TNB that may enter the air are likely to break down very slowly. It might persist for many years in the air. 1,3-DNB is also likely to break down in the air; however, we do not know how long this would take. Both compounds are slightly soluble in water. 1,3-DNB evaporates slowly from water; 1,3,5-TNB does not evaporate from water. Neither compound sticks strongly to soil; therefore, both can move through soil into groundwater. 1,3-DNB breaks down slowly in water and soil. It stays for days to months in water. Although 1,3,5-TNB probably breaks down in water and soil, we do not know how long this takes. Neither compound is likely to build up in fish or humans.
Pathways for 1,3-DNB and 1,3,5-TNB in the body
1,3-DNB can enter your bloodstream if you breathe it in the air or get it on your skin. There is no information on how 1,3,5-TNB can enter or exit your body. Exposure of the general population to 1,3-DNB or 1,3,5-TNB is not likely, so most people exposed to 1,3-DNB have come in contact with it in their work place. Results of studies in people and animals show that 1,3-DNB enters the body very quickly through the skin or lungs. Once 1,3-DNB is inside your body, it breaks down quickly. 1,3-DNB and its related breakdown products also exit the body very quickly in the urine. Some breakdown products of 1,3-DNB may also leave in the feces. Results of studies in people and animals show that most of the 1,3-DNB exits the body within 2 to 3 weeks after exposure.
Health effects of 1,3-DNB and 1,3,5-TNB
You should know that one way to learn whether a chemical will harm people is to determine how the body absorbs, uses, and releases the chemical. For some chemicals, animal testing may be necessary. Animal testing may also help identify such health effects as cancer or birth defects. Without laboratory animals, scientists would lose a basic method for getting information needed to make wise decisions that protect public health. Scientists have the responsibility to treat research animals with care and compassion. Scientists must comply with strict animal care guidelines because laws today protect the welfare of research animals.
Additionally, there are vigorous national and international efforts to develop alternatives to animal testing. The efforts focus on both in vitro and in silico approaches and methods. For example, the National Toxicology Program (NTP) at the National Institute of Environmental Health Sciences (NIEHS) created the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) in 1998. The role of NICEATM is to serve the needs of high quality, credible science by facilitating development and validation—and regulatory and public acceptance—of innovative, revised test methods that reduce, refine, and replace the use of animals in testing while strengthening protection of human health, animal health and welfare, and the environment. In Europe, similar efforts at developing alternatives to animal based testing are taking place under the aegis of the European Centre for the Validation of Alternative Methods (ECVAM).
1,3-DNB can enter your bloodstream if you breathe it in the air or get it on your skin. There is no information on how 1,3,5-TNB can enter or exit your body. Exposure of the general population to 1,3-DNB or 1,3,5-TNB is not likely, so most people exposed to 1,3-DNB have come in contact with it in their work place. Results of studies in people and animals show that 1,3-DNB enters the body very quickly through the skin or lungs. Once 1,3-DNB is inside your body, it breaks down quickly. 1,3-DNB and its related breakdown products also exit the body very quickly in the urine. Some breakdown products of 1,3-DNB may also leave in the feces. Results of studies in people and animals show that most of the 1,3-DNB exits the body within 2 to 3 weeks after exposure.
Medical tests for exposure to 1,3-DNB and 1,3,5-TNB
No tests are available commercially to determine if you have been exposed to 1,3-DNB or 1,3,5-TNB. There are tests to detect 1,3-DNB and its breakdown products in the blood and urine of exposed animals, but these tests have not been used for people.
Further Reading
- The Agency for Toxic Substances and Disease Registry
- Interagency Coordinating Committee on the Validation of Alternative Methods
- European Centre for the Validation of Alternative Methods
- Institute for Laboratory Animal Research
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