Hi there - This pump is fitted with rubber seals as standard. However, viton seals can be fitted on request. Viton seals make the pump suitable to transfer diesel (noting that if you do regularly transfer diesel with this pump, that it is recommended the seals are replaced every 12-24 months)...so in relation to chemicals, it is difficult to advise as different chemicals would have varying impact on the seals; if you intend to use chemicals /chemical mix that would be harsher on the seals than diesel, then it would be better to consider a specialist Chemical Transfer pump. Otherwise if your chemical mix would be equal or milder than diesel in terms of impact on the pump's seals, then this model of pump would be suitable for your spraying requirements (with viton seals fitted). Hope that helps, thanks.