Time Sensitive Chemicals

It is important to be aware of any potential time sensitive chemicals that are present. The official RMS policies along with a list of chemicals that fall under the definition of ‘time sensitive’ can be found here:

 Time Sensitive Chemicals Storage and Disposal Guidelines


Chemicals that develop more hazards over time are defined as time sensitive. Common examples include:

  • Chloroform
    •  Degrades into phosgene gas which is incredibly toxic
  • Anhydrous HF
    • Degrades into hydrogen while in metal containers, causing the container to burst
  • Peroxide Forming Compounds
    • Vinylic chemicals like vinyl acetate and vinyl chloride , some cyclocarbons, cyclohexanol and cyclohexene 
    • These chemicals will degrade into highly reactive shock sensitive explosives

All time sensitive chemicals need to be dated both on arrival and on opening. If one of these chemicals is not completely used within 1 year of opening it should be disposed of through RMS.

Peroxide forming chemicals should be tested every 2 months with commercial test strips. Labs owning peroxide forming chemicals are responsible for purchasing their own test strips. If a material is determined to have a peroxide level of over 50 ppm it should be disposed of IMMEDIATELY through RMS.  Spring Clean-Up is an excellent time to make sure there are no expired chemicals and that chemicals are segregated properly.  

RMS will NO LONGER pay for removal of expired chemicals that require specialized training, i.e. old peroxides.

It is imperative that LSOs are familiar with incompatible chemical types and any time sensitive chemicals that are present in their space. Please make sure to read over the relevant sections that apply to your lab.