Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Usage | Class | Performance | Performance test | Particulate size approaching 100% retention | Test Standard |
| --- | --- | --- | --- | --- | --- |
| Primary filters | G1 | 65% | Average value | >5µm | BS EN779 |
| Primary filters | G2 | 65–80% | Average value | >5µm | BS EN779 |
| Primary filters | G3 | 80–90% | Average value | >5µm | BS EN779 |
| Primary filters | G4 | 90%– | Average value | >5µm | BS EN779 |
| Secondary filters | F5 | 40–60% | Average value | >5µm | BS EN779 |
| Secondary filters | F6 | 60–80% | Average value | >2µm | BS EN779 |
| Secondary filters | F7 | 80–90% | Average value | >2µm | BS EN779 |
| Secondary filters | F8 | 90–95% | Average value | >1µm | BS EN779 |
| Secondary filters | F9 | 95%– | Average value | >1µm | BS EN779 |
| Semi Hepa | H10 | 85% | Minimum value | >1µm | BS EN1822 |
| Semi Hepa | H11 | 95% | Minimum value | >0.5µm | BS EN1822 |
| Semi Hepa | H12 | 99.5% | Minimum value | >0.5µm | BS EN1822 |
| Hepa | H13 | 99.95% | Minimum value | >0.3µm | BS EN1822 |
| Hepa | H14 | 99.995% | Minimum value | >0.3µm | BS EN1822 |
Question:
Which Test Standard has a Usage of secondary filters, and a Class of f5? Question 4
Answer:
BS EN779