DMDS is stored in tightly closed stainless-steel containers, kept upright in a cool, dry, well-ventilated and fireproof area that has no drain or sewer access, held apart from oxidants and acids, with every ignition source controlled all year round.
Dimethyl disulfide is a colourless oily liquid with a garlic-like odour, supplied as a refinery sulfiding chemical in drums, returnable cylinders, totes and ISO tanks.
Storage Conditions for DMDS
DMDS is kept cool, dry and well ventilated, in closed containers, inside a fireproof area that has no drain or sewer access and can hold both spilled liquid and the water used to fight a fire. Allow no open flames, no sparks and no smoking anywhere in the area.
Temperature and Ventilation
Run the store as a flammable-vapour area in every season. ICSC 1586 puts the flash point at 10 °C closed cup, below normal indoor temperature.
“Cool” carries no number here: no authoritative source states a maximum storage temperature for DMDS. Keep containers out of direct sun and away from steam lines, heaters and hot surfaces.
Every published flash point is below 37.8 °C (100 °F), so an inside storage room falls under the flammable-liquid rules of 29 CFR 1910.106: at least six complete air changes an hour, wiring approved for Class I Division 2, a Division 1 zone extending five feet in all directions from any point of vapour release, and the nozzle bonded to the container whenever liquid is drawn off.
The vapour is 3.2 times as dense as air. It collects in pits, sumps and low corners, so local exhaust belongs at the points where vapour is released and low-level areas have to be part of the ventilation design.
Segregation and Containment
Keep DMDS away from oxidants and acids, and put it in an area built to hold everything that can escape from it.
The area needs no drain or sewer access and must hold spilled liquid together with fire-fighting effluent; for tank storage, the diked area is sized to contain the largest tank within it, assuming that tank full.
Containers, Tanks and Seals for DMDS
Stainless steel is the container material at every scale DMDS is supplied in — drums, returnable cylinders, stainless totes, ISO tanks and tank trailers — and the working rule for a buyer is to keep the material in the packaging it arrived in rather than decanting it into site vessels.
For any other metallurgy, ask the producer for materials-of-construction data before the liquid goes near it. Carbon steel is neither ruled in nor out by anything published: the US registration file for the fumigant grade lists one-year ambient storage studies run in carbon-steel drums alongside identical studies in stainless, and the results were never published.
In an otherwise stainless system the elastomers are the bungs, tote valve seats, pump seals and hose liners. Check every elastomer against the producer’s compatibility data before it sees the liquid. One producer specifies a PTFE-lined hose for its own transfer equipment.
Keep containers tightly closed and upright, and reseal an opened container carefully. Open a drum carefully as well, because the contents may be under pressure.
How to Store DMDS Long Term
DMDS does not degrade sitting in a closed drum. No producer publishes a shelf life, expiry date or retest interval for it.
Before a lot that has sat for months goes to the sulfiding run, re-check it against its own certificate of analysis: appearance, purity, water content and methylmercaptan content. The DMDS we supply is specified at 99.5 % purity minimum, colourless to light yellow. Colour is no guide to age.
Detection thresholds are reported at 7 to 12 ppb, far below the 0.5 ppm exposure limit, so a smell in the store points to a container or a vent to find long before it means anyone is over the limit.
Check drum condition and seals on arrival, and keep opened drums out of long-term stock.
Safe Handling of DMDS in Storage
Handle DMDS in storage under ventilation, with respiratory and skin protection, and with no ignition source in the area: it is toxic if inhaled and a highly flammable liquid. Containers arrive labelled UN 2381, Class 3 with subsidiary risk 6.1, Packing Group II and marine pollutant, and the drum’s GHS label carries the signal word Danger.
The store is run to 0.5 ppm as an eight-hour TWA with a skin notation, the ACGIH TLV. Local exhaust at transfer and sampling points keeps routine work below it, an organic-vapour air-purifying respirator covers opening and transferring, and positive-pressure supplied air is required where a release is uncontrolled or the concentration is unknown.
Gloves, protective clothing and goggles are worn for any handling. Ask the glove supplier for permeation and breakthrough times.
For a spill, eliminate every ignition source, ground the equipment, absorb the liquid with earth, sand or other non-combustible material using non-sparking tools, and keep it out of sewers, basements and low areas. For a fire, use dry chemical, carbon dioxide, alcohol-resistant foam or water spray and cool drums with water spray; the low flash point makes water spray inefficient against the burning liquid itself. The response guide for flammable toxic liquids calls for isolating a spill area 50 metres in all directions, and 800 metres where a tank or tanker is involved in the fire.