# RJ-4 (MIL-F-82522) — Chemical resistance ratings for common elastomers

For RJ-4 (MIL-F-82522), nitrile (nbr) is 2; epdm is 4; neoprene (cr) is 4; sbr is 4; silicone (vmq) is 4, verified against its source on 2026-08-12.

- **Chemical:** RJ-4 (MIL-F-82522) _(verified: appears in the quote below)_
- **Nitrile (NBR):** 2 _(verified: appears in the quote below)_
- **EPDM:** 4 _(verified: appears in the quote below)_
- **Neoprene (CR):** 4 _(verified: appears in the quote below)_
- **SBR:** 4 _(verified: appears in the quote below)_
- **Silicone (VMQ):** 4 _(verified: appears in the quote below)_
- **Butyl (IIR):** 4 _(verified: appears in the quote below)_
- **Polyacrylate (ACM):** 2 _(verified: appears in the quote below)_
- **Hypalon (CSM):** X _(verified: appears in the quote below)_
- **Viton (FKM):** 1 _(verified: appears in the quote below)_
- **Polyurethane (AU/EU):** 2 _(verified: appears in the quote below)_
- **Fluorosilicone (FVMQ):** 1 _(verified: appears in the quote below)_
- **Aflas (TFE/P):** X _(verified: appears in the quote below)_
- **Kalrez (FFKM):** 1 _(verified: appears in the quote below)_
- **Rating scale:** 1 = Satisfactory, 2 = Fair, 3 = Doubtful, 4 = Unsatisfactory, X = Insufficient Data _(verified: appears in the quote below)_

## What the source says

> RJ-4 (MIL-F-82522) | 2 | 4 | 4 | 4 | 4 | 4 | 2 | X | 1 | 2 | 1 | X | 1 |

## Source

- https://mykin.com/rubber-chemical-resistance-chart-5

Last verified: 2026-08-12. Review by: 2028-08-11.
Part of [Chemical resistance ratings for common elastomers](https://referencesource.org/chemical-elastomer-material-compatibility/).