I guess the air we breathe, the food we eat, the water we drink, and the people we listen to have also in some cases been toxic to humans.
There are a number of very specific materials that are used in the conservation and restoration of leather.
Aluminum alkoxide - 1% in white spirit, used as a chemical restabilizing retanning agent for red rot leather.
Bavon ASAK ABP - leather lubricating compound. Alkenyl succinic acid derivative that is soluble in white spirits and Genklene
Bavon ASAK 520S
British Museum leather dressing or Pliantine
Sodium Carboxymethyl cellulose or CMC
Connolly's Leather Food - a dressing for hide upholstery, leather goods and clothing
DDT - now banned
p-dichlorobenzene - mothball
Disinfectant 1473 - used as a fungicide
Dowicide A - water-soluble fungicide made of sodium salt of orth-phenyl phenol
Facteka A - granular cleaner for suede or leather with abraded surfaces. Rubber like and made from rapeseed oil.
French chalk or talc
Genklene - non-flammable (1,1,1-trichloroethane)
Invasol S - Synthetic anionic oil
Isopropanol or Isopropyl alcohol
Japanese tissue paper
Lipoderm Liquor SA
Lipoderm Liquor LPK - synthetic anionic oil free of natural fat
Lissapol N. - non-ionic detergent
Neutralfat SSS - stabilized olein soap which on drying loses emulsifying property so that it no longer promotes absorption of water
Plexisol - consolidant for leather affected by red rot. Polyacrylate resin preparation containing 25% solids. Must be diluted with Genklene.
Pliancreme - cream form of British Museum leather dressing, emulsified with water, containing a fungicide.
Pliantex - same as Plexisol (see above)
Preventol L - fungicide; sodium salt of chlorinated phenol
PEG 400 or polyethylene glycol
Saddle soap -
Santobrite -fungicide for leather, Pentachlorophenol
Silicon leather wax
Spun-bonded polyester fabrics
Vulpex - potassium oleate soap, soluble in water or white spirit
White spirit BS245
Nikon specifically warns against p-dichlorobenzene - mothball and cautions against it's use in proximity to it's camera systems...
Is p-dichlorobenzene - toxic? Yes 1,4-Dichlorobenzene can irritate the nose and throat causing coughing and wheezing. * Exposure can cause headache, dizziness, swelling around the eyes, nausea and vomiting. * Repeated exposure to 1,4-Dichlorobenzene can damage the nervous system causing weakness, trembling and numbness in the arms and legs. Source: https://nj.gov/health/eoh/rtkweb/documents/fs/0643.pdf
Please stay safe traderjohn, all the best on your journey...