I visit a lot of caves in the Canadian Rockies, and there are similar concerns with transporting microorganisms from cave to cave, as well as diseases such as white nose syndrome in bats. For the amount of organisms you're going to pick up on your nylon rope, it should be sufficient to clean your ropes thoroughly in a bath with Dawn soap. The soap will kill most microorganisms, and so long as you're getting all the soil off your ropes you shouldn't have any concerns. Physically transporting mud on your boots and clothes from one location to another is a far greater concern.
If it comes down to it, there's an argument to be made about compromising the integrity of your ropes with chemical treatments not specifically designed for safety ropes. If they push the matter, you can get something like Sterling rope wash just so you can tell them you use specialty rope cleaners. Either way, they should be satisfied to see a squeaky clean rope.
One thing that can be done to control the transfer of microorganisms, is to dedicate gear for specific areas. In some caves for example, there are rappels where we will fix custom lengths of rope in the cave. They'll spend their entire usable life in the same cave, which completely eliminates the possibility of cross contamination. This of course comes with the financial commitment of investing in multiple ropes.
The government of British Columbia has Standard Operating Procedures (SOP's) for decontaminating caving gear. The SOP's are specific to the fungus Pseudogymnoascus destructans (Pd) which causes White Nose Syndrome in bats, but may be effective against other organisms as well. There are some treatments that do not require chemicals.
- Soaking in disinfectant containing at least 0.26% ammonium quaternary compounds for 10 minutes. There is currently much debate
about what products available in Canada can be used at this
concentration, as most manufacturers do not provide safety information
regarding mixing their products at this strength. Until further
guidance can be provided by the US Fish and Wildlife Service and/or
the Canadian White Nose Syndrome Interagency Committee, we recommend
you employ caution with whatever chemical you end up using. Some
possible concentrates that you may consider dilution include: Zep Aqua
San, Virkon, Aseptol2000, etc. Two brands of disinfecting wipes sold
in Canada have the minimum concentration of ammonium quaternary
compound required to kill Pd (≥0.26% quats): Clorox and Lysol
disinfecting wipes. MSDS:
http://www.thecloroxcompany.com/downloads/msds/wipes/cloroxdisinfectingwipesfreshscentjwcanadafca.pdf
and http://www.rbnainfo.com/MSDS//CA/CA%20-
%20LYSOL%20Disinfecting%20Wipes%20(all%20sizes,%20all%20scents)%20-%20English%20(Feb%202012).pdf Due to the uncertainty that still
surrounds the safety and efficacy of Canadian fungicidal products, it
is recommended that you use the hot water method (below) when
possible.
- Soaking in 10% bleach (1:10 or one part bleach to 9 parts water) for 10 minutes (approximately half cup bleach in a litre of water).
The MSDS is at:
http://www.iaprisonind.com/downloads/msds/IPI-ChlorineBleach10.pdf
- Submersing in water at a temperature of at least 550C for >20 minutes.
- Steam-cleaning of large pieces of equipment may be used where other methods are impractical but its efficiency has not been tested.
- New as of April 2016 – four new products are now recommended for inclusion in decontamination procedures: ethanol (60% or greater),
isopropanol (60% or greater), STANDARD OPERATING PROCEDURES FOR
MINIMIZING WHITE NOSE SYNDROME TRANSMISSION, MARCH 2017 isopropyl
wipes (70%), or hydrogen peroxide wipes (3%). The latter two wipes
have been found effective against Pd on contact and do not require
soaking. Use of ethanol and isopropanol requires at least one minute
of soaking.
Looking at the MSDS for SteriGENE, it's dangerously corrosive when concentrated. There may be a diluted mixture that is suitable for your ropes, but I'd probably explore other options for decontaminating my safety line first.