As I noted in 2007, the #1 cause of process vessel deflagrations is the manual additions of powders to process vessels which have a flammable atmosphere. NFPA 77 covers this hazard with several solutions, yet many facilities are either not aware of these risks and solutions or simply have their head buried regarding these catastrohic risks.
On May 3, 2005, Employees #1 and #2 were pouring ingredients into a large blender at a manufacturer of vitamins in gelatin, tablet, and caplet forms. The blender tumbled to make a homogenous mixture of the ingredients. When ingredients were to be added, the mixer would be stopped with the opening at the top. Employees would then attach an electric circular shaker box that vibrated to break up the powder as it went down into the blender.
The shaker box had a local exhaust system made of plastic throughout. A plastic-coated conductor within the plastic pipe helped maintain the pipe’s integrity. There was no means of bonding or grounding.
Employees #1 and #2 were injured when they each poured an ingredient into the blender at the same time, a dust deflagration (flash fire) occurred, and flames came out of the blender. The employees were hospitalized at Sherman Oaks Burn Center for burns on their hands and backs. The exact source of the ignition could not be determined.
| Violations/Penalties | Serious | Willful | Repeat | Other | Unclass | Total |
|---|---|---|---|---|---|---|
| Initial Violations | 4 | 2 | 6 | |||
| Current Violations | 4 | 2 | 6 | |||
| Initial Penalty | $44,500 | $0 | $0 | $370 | $0 | $44,870 |
| Current Penalty | $19,685 | $0 | $0 | $370 | $0 | $20,055 |
| FTA Penalty | $0 | $0 | $0 | $0 | $0 | $0 |
| # | Citation ID | Citaton Type | Standard Cited | Issuance Date | Abatement Due Date | Current Penalty | Initial Penalty | FTA Penalty | Contest | Latest Event | Note |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. | 01001 | Other | 25000010 A | 10/31/2005 | 11/18/2005 | $185 | $185 | $0 | 11/15/2005 | F – Formal Settlement | |
| 2. | 01002 | Other | 5143 A05 – General Requirements of Mechanical Ventilation Systems | 11/02/2005 | 12/07/2005 | $185 | $185 | $0 | 11/15/2005 | F – Formal Settlement | |
| 3. | 02001 | Serious | 5174 A – Combustible Dusts–General. | 11/01/2005 | 12/06/2005 | $18,000 | $25,000 | $0 | 11/15/2005 | F – Formal Settlement | |
| 4. | 03001 | Serious | 5174 C – Combustible Dusts–General. | 11/01/2005 | 12/06/2005 | $675 | $6,750 | $0 | 11/15/2005 | F – Formal Settlement | |
| 5. | 04001 | Serious | 5174 D Combustible Dusts–General. | 11/01/2005 | 12/06/2005 | $675 | $9,375 | $0 | 11/15/2005 | F – Formal Settlement | |
| 6. | 05001 | Serious | 23950051 A | 11/01/2005 | 12/06/2005 | $335 | $3,375 | $0 | 11/15/2005 | F – Formal Settlement |
Source: https://www.osha.gov/ords/imis/establishment.inspection_detail?id=300829553