---
kind: "section"
citation: "46 C.F.R. § 154.1205"
title: "46"
number: "154.1205"
heading: "Mechanical ventilation system: Standards."
url: "https://uscodex.org/cfr/46/154.1205"
---

# §154.1205. Mechanical ventilation system: Standards.

- (a) Each exhaust type mechanical ventilation system required under [§ 154.1200 (a)](/cfr/46/154.1200.md?p=a) must have ducts for vapors from the following:
  - (1) **The deck level.**
  - (2) **Bilges.**
  - (3) If the vapors are lighter than air, the top of each space that personnel enter during cargo handling operations.
- (b) The discharge end of each duct under [paragraph (a)](#a) of this section must be at least 10 m (32.8 ft.) from ventilation intakes and openings to accommodations, service, control station, and other gas-safe spaces.
- (c) Each ventilation system under § [154.1200 (a)](/cfr/46/154.1200.md?p=a) and [(b)(1)](/cfr/46/154.1200.md?p=b-1) must change the air in that space and its adjoining trunks at least 30 times each hour.
- (d) Each ventilation system for a gas-safe cargo control station in the cargo area must change the air in that space at least eight times each hour.
- (e) A ventilation system must not recycle vapor from ventilation discharges.
- (f) Each mechanical ventilation system must have its operational controls outside the ventilated space.
- (g) No ventilation duct for a gas-dangerous space may pass through any machinery, accommodation, service, or control space, except as allowed under [§ 154.703](/cfr/46/154.703.md).
- (h) Each electric motor that drives a ventilation fan must not be within the ducts for any space that may contain flammable cargo vapors.
- (i) Ventilation impellers and the housing in way of those impellers on a flammable cargo carrier must meet one of the following:
  - (1) The impeller, housing, or both made of non-metallic material that does not generate static electricity.
  - (2) **The impeller and housing made of non-ferrous material.**
  - (3) **The impeller and housing made of austenitic stainless steel.**
  - (4) The impeller and housing made of ferrous material with at least 13mm (0.512 in.) tip clearance.
- (j) No ventilation fan may have any combination of fixed or rotating components made of an aluminum or magnesium alloy and ferrous fixed or rotating components.
- (k) Each ventilation intake and exhaust must have a protective metal screen of not more than 13mm (0.512 in.) square mesh.

## Notes

### Authority

Authority: 46 U.S.C. 3703, 9101; Department of Homeland Security Delegation No. 0170.1.

### Source

Source: CGD 74-289, 44 FR 26009, May 3, 1979, unless otherwise noted.