This model is based on the in vitro skin model Skin2 [5] which had been discontinued in October 1996. It was further proposed by industry to apply the model in a tiered strategy to identify those chemicals that are predicted to be likely to be phototoxic in the 3T3-NRU-PT but are negative in vivo [6].
401(k) contribution rules. On a pretax basis, employees can't contribute above certain limits. In 2015, for instance, the limit is $18,000; those 50 and older can make additional catch-up contributions of $6,000.This money is not counted toward income, and all gains are tax-deferred. The limits are the same for Roth 401(k)s, though the contributions do count toward income and all gains are tax-free.But employees can sock away a lot more retirement cash if their company plan offers an after-tax option in a traditional 401(k).he limits are the same for Roth 401(k)s, though the contributions do count toward income and all gains are tax-free. But employees can sock away a lot more retirement cash if their company plan offers an after-tax option in a traditional 401(k).
1 The catch-up contribution limit for employees aged 50 and over who participate in 401k, 403(b), most 457 plans, and the federal government's Thrift Savings Plan remains unchanged at $5,500. 2  The limit on annual contributions to an Individual Retirement Arrangement (IRA) remains unchanged at $5,500.ighlights of the IRS announcement include the following: 1  The elective deferral (contribution) limit for employees who participate in 401k, 403(b), most 457 plans, and the federal government's Thrift Savings Plan remains unchanged at $17,500.