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FINANCIAL INSTRUMENTS - Sensitivity analysis (Details) - BRL (R$) R$ in Thousands | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016
Foreign currency risk |  |
Sensitivity analysis |  |
Percentage of change | 5.00% | 5.00%
Impact on income statement based on change in assumption | R$ 129,209 | R$ 253,294
Impact on income statement based on change in assumption, after effects of changes in net investment hedge | R$ 79,088 | R$ 177,711
Interest rate risk |  |
Sensitivity analysis |  |
Interest rate change (as a percent) | 0.10% | 0.10%
Impact on income statement based on change in assumption | R$ 54,908 | R$ 63,416
Products sold price risk |  |
Sensitivity analysis |  |
Percentage of change | 1.00% | 1.00%
Impact on income statement based on change in assumption | R$ 369,176 | R$ 376,517
Raw materials and commodity price risk |  |
Sensitivity analysis |  |
Percentage of change | 1.00% | 1.00%
Impact on income statement based on change in assumption | R$ 234,239 | R$ 228,637
Interest rate and foreign currency swaps risk |  |
Sensitivity analysis |  |
Percentage of change | 5.00% | 5.00%
Interest rate change (as a percent) | 0.10% | 0.10%
Impact on income statement based on change in assumption | R$ 6,479 | R$ 9,870
Non deliverable forwards risk |  |
Sensitivity analysis |  |
Percentage of change | 5.00% | 5.00%
Impact on income statement based on change in assumption | R$ 1,480 | R$ 15,816

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