RDX

2021-10-29

RDX, which stands for Research Department explosive, is an explosive nitroamine widely used in military and industrial applications. It was developed as an explosive which was more powerful than TNT, and it saw wide use in World War II. RDX, also known as cyclonite, hexogen, and T4 has the chemical formula C3H6N6O6. Its chemical name is cyclotrimethylenetrinitramine. In its pure, synthesised state RDX is a white, crystalline solid. It is often used in mixtures with other explosives and plasticizers, phlegmatisers or desensitisers. RDX is stable in storage and is considered one of the most powerful and brisant of the military high explosives. [1] RDX is a synthetic chemical, it does not occur naturally in the environment. It creates fumes when it is burned with other substances. [2]

Uses [1]

RDX was widely used during World War II, often in explosive mixtures with TNT such as Torpex, Composition B, Cyclotols, and H6. RDX was used in one of the first plastic explosives. Outside military applications, RDX is also used in controlled demolition to raze structures.

Sources & Routes of Exposure

Sources of Exposure [3]

  • Exposure typically only occurs in people who work with RDX and can potentially breathe RDX dust or get it on their skin.
  • You can be exposed if you breathe RDX fumes from explosions or bombing ranges of burning RDX.
  • You may be exposed to RDX by drinking contaminated water or by touching contaminated soil if you live near facilities that produce or use RDX. RDX has been found in water and soil near some ammunition plants, current or former military installations and storage areas.
  • You may be exposed to RDX by ingesting agricultural crops grown in contaminated soils irrigated with contaminated water.

Routes of Exposure [4]

  • Inhalation – Minor route of exposure for general population. Predominant route of exposure for workers.
  • Oral – Predominant route of exposure to for non-occupational exposure. Exposure can occur through ingestion of contaminated drinking water or consumption of agricultural products irrigated with contaminated water.
  • Dermal – Skin contact may occur during manufacture of RDX.

In the Environment

  • RDX can be released to the environment through spills, firing of munitions, disposal of ordnance, open incineration and detonation of ordnance, leaching from inadequately sealed impoundments and demilitarisation of munitions. The compounds can also be released from manufacturing and munitions processing facilities.
  • In the atmosphere, RDX is expected to exist in the particulate phase and settles by wet or dry deposition.
  • Low soil sorption coefficient (KOC) values indicate that RDX is not significantly retained by most soils and can migrate to groundwater. However, the rate of migration depends on the composition of the soil.
  • RDX can migrate through the vadose zone and contaminate underlying groundwater aquifers, especially at source areas that have permeable soils, a shallow groundwater table and abundant rainfall.
  • RDX dissolves slowly in water because of its slow rate of dissolution from the solid phase and does not evaporate from water readily as a result of its low vapour pressure.
  • Phototransformation of RDX in soil is not significant; however, it is the primary physical mechanism that degrades RDX in aqueous solutions. Consequently, RDX is not expected to persist for a long period of time in surface waters.
  • Based on its low octanol-water partition coefficient (KOW) and low experimental bioconcentration factor, RDX has a low bioconcentration potential in aquatic organisms.
  • Results from a study indicate that RDX may bioaccumulate in plants and could be a potential exposure route to herbivorous wildlife.

Health Effects [4]

  • The most sensitive target of toxicity is the nervous system. Seizures, convulsions, and tremors have been observed in humans and animals ingesting RDX.
  • Some studies have found changes in serum chemistry parameters suggestive of impaired liver function; histological alterations have not been found in the liver and the changes in clinical chemistry parameters were not considered biologically significant.
  • Small decreases in erythrocyte and haemoglobin levels have been found in rodents, but this has not been consistently found longer-term studies.
  • EPA has determined that RDX is a possible human carcinogen based on the presence of liver tumours in mice exposed to RDX in the diet for 1–2 years. However, a re-evaluation of this mouse study resulted in a re-classification of some of the hepatocellular adenomas as foci of cytoplasmic alterations.

Safety [6]

First Aid Measures

  • Inhalation: Remove victim from area of exposure – avoid becoming a casualty. Remove contaminated clothing and loosen remaining clothing. Allow patient to assume most comfortable position and keep warm. Keep at rest until fully recovered. Seek medical advice if effects persist.
  • Skin Contact: If skin or hair contact occurs, immediately remove any contaminated clothing and wash skin and hair thoroughly with running water. A component of this material can be absorbed through the skin with resultant toxic effects. Seek immediate medical assistance.
  • Eye Contact: If in eyes, wash out immediately with water. In all cases of eye contamination, it is a sensible precaution to seek medical advice.
  • Ingestion: Immediately rinse mouth with water. If swallowed, give a glass of water to drink. Get to a doctor or hospital quickly.
  • Medical attention and special treatment: Treat symptomatically. Explosive material.

Fire Fighting Information

  • Hazards from combustion products: Explosive material. Avoid all ignition sources. Risk of explosion by shock, friction, fire or other sources of ignition. On burning will emit toxic fumes, including those of oxides of carbon and oxides of nitrogen.
  • Precautions for fire fighters and special protective equipment: Explosive material. Severe explosive hazard when shocked or exposed to heat. Confinement of burning material may result in detonation. In case of small fire where the actual explosive is not involved, carefully remove explosive to a safe distance, otherwise evacuate area immediately and allow to burn. Do NOT fight fire.
  • Hazchem Code: E

Exposure Controls & Personal Protection

Engineering Controls

  • Ensure ventilation is adequate and that air concentrations of components are controlled below quoted Exposure Standards.
  • Natural ventilation should be adequate under normal use conditions.

Personal Protective Equipment

  • It is recommended that to wear overalls, safety glasses and impervious gloves when handling RDX.
  • Always wash hands before smoking, eating, drinking or using the toilet.

Regulation

United States [7]

OSHA: The United States Occupational Safety & Health Administration has set the following Permissible Exposure Limit (PEL)for RDX:

  • Construction Industry: 29 CFR 1926.55 Appendix A — 1.5 mg/m3 TWA; Skin
  • Maritime: 29 CFR 1915.1000 Table Z-Shipyards — 1.5 mg/m3 TWA; Skin

ACGIH: The American Conference of Governmental Industrial Hygienists has set a Threshold Limit Value (TLV) for RDX of 0.5 mg/m3 TWA; Skin; Appendix A4 – Not Classifiable as a Human Carcinogen

NIOSH: The National Institute for Occupational Safety and Health (has set a Recommended Exposure Limit (REL) for RDX of 1.5 mg/m3 TWA, 3 mg/m3 STEL; Skin

Australia [8]

Safe Work Australia: Safe Work Australia has set a Time Weighted Average (TWA) concentration for RDX of 1.5mg/m3 for a 40-hour workweek.

References

https://en.wikipedia.org/wiki/RDX

http://www.atsdr.cdc.gov/toxfaqs/tfacts78.pdf

http://www.atsdr.cdc.gov/toxprofiles/tp78-c1.pdf

http://www.atsdr.cdc.gov/toxguides/toxguide-78.pdf

http://www.epa.gov/sites/production/files/2014-03/documents/ffrrofactsheet_contaminant_rdx_january2014_final.pdf

https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0ahUKEwiw-fb2xc3JAhXMpJQKHaeECNUQFggrMAM&url=http%3A%2F%2Fwww.oricaminingservices.com%2FDownload.ashx%3FFile%3D%252F2%252FMSDS%2B40%2BRDX%2BCord.pdf&usg=AFQjCNGXTqsHmHQzmOibPwrrL8FsCp9IzQ&bvm=bv.109332125,d.dGo

https://www.osha.gov/dts/chemicalsampling/data/CH_231075.html

http://www.safeworkaustralia.gov.au/sites/SWA/about/Publications/Documents/772/Workplace-exposure-standards-airborne-contaminants.pdf