Industrial gear lubricant additive package with biodegradable sulfur component

An additive package for industrial gear lubricants which meets OECD 301B comprising at least one sulfurized olefin that delivers greater than about 0.80 wt % active sulfur as measured at 150° C in ASTM D1662, wherein the at least one sulfurized olefin comprises from about 0.5 to about 20 wt % of at least one sulfurized olefin that is readily or inherently biodegradable as measured according to OECD301B, and from about 0.01 to about 1 wt % of a non-biodegradable sulfurized olefin comprising at least one of di-isobutylene, butylene, isobutylene, or mixtures thereof, wherein the non-biodegradable sulfurized olefin comprises less than 0.10 wt %, based on the total weight of the industrial gear oil lubricant, of a highly active non-biodegradable sulfurized olefin derived from di-isobutylene and less than 0.25 wt %, based on the total weight of the industrial gear oil lubricant, of a nominally active non-biodegradable sulfurized olefin derived from isobutylene.