Start hereRules checked 20 October 2026
A chemical tanker crew member closing a leaking manifold valve on a toxic cargo, or a gas carrier crew member isolating a leak of ammonia, needs more than breathing apparatus. Some cargoes burn or poison through the skin, and vapour reaches the body through any gap in the clothing. The protection is a suit that keeps gas out completely, worn with a breathing set, and it only works if it has no hole the size of a pinprick.
The IBC and IGC Codes require these suits on ships carrying the right products. The European standard EN 943 sets how gas-tight suits are built and tested. The maker’s instructions set the leak tests that keep them in service. This lesson connects the three.
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In this lesson
- A toxic cargo leak on a chemical tanker
- In plain words
- In detail
- What the rules say
- Flag and class notes
- Key numbers
- What inspectors find
- Quiz: 6 questions
Try it
A toxic cargo leak on a chemical tanker
In plain words
Two Codes decide what protective clothing is carried:
- The IBC Code for chemical tankers. Everyone working on loading and discharging gets chemical-resistant clothing that covers all skin. Ships carrying certain toxic cargoes must carry at least three complete sets of safety equipment, each letting a person enter a gas-filled space and work there for at least 20 minutes: breathing apparatus, protective clothing, boots, gloves, goggles, a fireproof lifeline and an explosion-proof lamp.1
- The IGC Code for gas carriers. At least three complete sets of safety equipment, and for some products the protective clothing must be gastight.2
A gas-tight suit is a one-piece suit with attached boots and gloves and a visor or hood, sealed so that gas cannot get in. The European standard EN 943 calls it Type 1. Type 1a has the breathing apparatus inside the suit, Type 1b outside it, and Type 1c is fed with air through a line.3
The suit is only safe if it is proven tight. That proof is a leak test: the suit is blown up with air to a set pressure, and the pressure must not fall more than a set amount in a set time.4
In detail
What the IBC Code requires (chemical tankers)
Chapter 14 of the International Code for the construction and equipment of ships carrying dangerous chemicals in bulk (IBC Code), as rewritten by resolution MSC.176(79) (in force 1 January 2007):1
| Para | Requirement |
|---|---|
| 14.1.1 | Protective equipment for crew on loading and discharging: large aprons, special gloves with long sleeves, suitable footwear, chemical-resistant coveralls, tight-fitting goggles or face shields, covering all skin |
| 14.1.2 | Kept in special lockers, not in accommodation spaces (except new or thoroughly cleaned equipment, or approved segregated stores) |
| 14.2.1 | Where column o of chapter 17 lists 15.12, 15.12.1 or 15.12.3 (toxic products): at least three complete sets of safety equipment, each for entry and at least 20 minutes of work in a gas-filled compartment, in addition to the SOLAS fire-fighter’s outfits |
| 14.2.2 | One set: SCBA (not stored oxygen); protective clothing, boots, gloves, tight-fitting goggles; fireproof lifeline with belt resistant to the cargoes; explosion-proof lamp |
| 14.2.3 | Air supply: spare charged bottles for each set, or a compressor and charging manifold, or spare bottles of at least 6,000 l free air for each apparatus |
| 14.2.5 | At least one set in a marked locker near the cargo pump-room |
| 14.2.6 | Breathing apparatus inspected monthly by a responsible officer and logged; inspected and tested by an expert at least once a year |
| 14.3.1 | Where column n says “Yes”: respiratory and eye protection for emergency escape for everyone on board; no filter types; SCBA at least 15 minutes; marked as not for fire-fighting or cargo handling |
| 14.3.4 | Marked decontamination showers and an eyewash on deck, usable in all ambient conditions |
What the IGC Code requires (gas carriers)
Chapter 14 of the 2016 IGC Code (resolution MSC.370(93), gas carriers built on or after 1 July 2016):2
| Para | Requirement |
|---|---|
| 14.1.1 | Protective equipment, including eye protection to a recognised standard, for crew in normal cargo operations |
| 14.1.2 | Kept in suitable, clearly marked, readily accessible lockers |
| 14.1.3 | Compressed air equipment inspected at least monthly by a responsible officer and logged; inspected and tested by a competent person at least once a year |
| 14.3.1 | At least three complete sets of safety equipment, in addition to the fire-fighter’s outfits, for entry and work in a gas-filled space |
| 14.3.2 | Each set: positive-pressure SCBA with full face mask, at least 1,200 l of free air; protective clothing, boots and gloves to a recognised standard; steel-cored rescue line with belt; explosion-proof lamp |
| 14.4.2 | For products listed in column i: escape respiratory and eye protection for everyone, not filter type, SCBA at least 15 minutes |
| 14.4.3 | Decontamination showers and eyewash stations on deck |
| 14.4.4 | The protective clothing of 14.3.2.2 shall be gastight for those products |
EN 943: what “gas-tight” means
EN 943 is the European standard for gas-tight (Type 1) chemical protective suits. Part 1 (EN 943-1, current edition 2015+A1:2019) sets the performance requirements; Part 2 (EN 943-2:2019) adds requirements for suits used by emergency teams (ET).3 The types are:3
| Type | Air supply |
|---|---|
| 1a | Self-contained breathing apparatus worn inside the suit |
| 1b | Self-contained breathing apparatus worn outside the suit (mask sealed to the suit) |
| 1c | Breathable air at positive pressure through an air line |
Non-gas-tight chemical suits (spray-tight, liquid-tight, particle-tight types) are covered by other standards and do not meet a “gastight” requirement such as IGC 14.4.4. Whatever the type, check that the suit material resists the specific cargo: makers publish permeation (breakthrough time) tables for each chemical.
Pre-use, after-use and periodic checks
Intervals and values come from the maker’s instructions for use (IFU). As an example, the Dräger CPS 5900 (a Type 1a suit) instructions set:4
| Check | Before use | After use | Annually |
|---|---|---|---|
| Visual inspection (also on receipt): outer for holes, cuts, abrasion; seam tape; visor seal; gloves inner and outer; zip | yes | yes | yes |
| Suit leak (tightness) test (also on receipt) | yes | yes | |
| Suit valve test | yes | yes |
The annual interval is extended to two years for suits stored in their carrying bag. Dräger also asks for the zip to be lubricated after every use and for all maintenance to be recorded.4
The leak test (Dräger CPS 5900 example, based on ISO 17491-1):4
- Connect the test unit; inflate the suit to 17.5 mbar and close the exhaust valve.
- Settle for 10 minutes at about 17 mbar, topping up, so pressure and temperature stabilise.
- Reduce to 16.5 mbar and start a 6-minute test.
- Pass if the pressure drop is 3 mbar or less. If more, check the test set-up; if the set-up is right, the suit is not tight.
Suit valve test (same IFU): apply 10 mbar overpressure for 1 minute; the valve is tight if the change is less than 1 mbar; otherwise clean or replace the valve disc and repeat.4
Other makers use different pressures and times. Use the values in your suit’s own IFU and the maker’s test kit, and keep a record per suit serial number.
Storage and life
- Store clean, in a dark, cool, dry and airy place without pressure or stress, out of UV light and direct sunlight and away from ozone, folded and bagged as the IFU says (Dräger CPS 5900: −20 °C to +25 °C).4
- The material life is set by the maker. Dräger states the properties are maintained for at least ten years from manufacture if unused and stored and maintained as instructed.4
- Suits that fail an inspection or leak test, have been exposed to intense heat or UV for long periods, have reached their life span, or have been contaminated with chemicals are taken out of service; Dräger recommends this for any CPS 5900 contaminated with toxic, known or unknown chemicals. Dräger allows uncontaminated discarded suits to be marked “for training purposes only”.4
- The IBC Code keeps used work clothing and protective equipment out of the accommodation unless cleaned.1
What the rules say
- IBC Code paragraph 14.1.1 requires protective equipment for crew in loading and discharging that covers all skin, including chemical-resistant coveralls, long-sleeved gloves, footwear and goggles or face shields.1
- IBC Code paragraph 14.2.1 requires ships carrying cargoes listed with 15.12, 15.12.1 or 15.12.3 in column o to carry at least three complete sets of safety equipment, each allowing entry into a gas-filled compartment and work there for at least 20 minutes.1
- IBC Code paragraph 14.2.6 requires breathing apparatus to be inspected at least monthly by a responsible officer, recorded in the log-book, and inspected and tested by an expert at least once a year.1
- IBC Code paragraph 14.3.4 requires suitably marked decontamination showers and an eyewash on deck, operable in all ambient conditions.1
- IGC Code paragraph 14.3.1 requires at least three complete sets of safety equipment, in addition to the fire-fighter’s outfits, and 14.3.2 requires each set to include positive-pressure SCBA of at least 1,200 l free air and protective clothing, boots and gloves to a recognised standard.2
- IGC Code paragraph 14.4.4 requires the protective clothing of 14.3.2.2 to be gastight on ships carrying the products for which section 14.4 is listed.2
- IGC Code paragraph 14.1.3 requires compressed air equipment to be inspected monthly by a responsible officer and inspected and tested by a competent person at least once a year.2
- MSC.581(110) section 9.5 recommends appropriate protective clothing where toxic substances or chemicals may contact the skin of those entering a space.5
- EN 943-1 sets performance requirements for Type 1 (gas-tight) chemical protective suits, and EN 943-2 for gas-tight suits used by emergency teams.3
Flag and class notes
The IBC and IGC Codes leave the suit standard to a “recognized standard”, so the approval of the equipment and its listing on the ship’s Certificate of Fitness are checked by the flag or the class society acting for it at survey. Ask your class society or flag which standard it accepts (EN 943 is widely used) and whether it wants leak test records shown at survey. The maker’s instructions for use remain the reference for test intervals and service life; MSC.581(110) asks for all equipment used for entry to be in good working condition and inspected and tested before use.5
Key numbers
| What | Value |
|---|---|
| IBC complete sets of safety equipment (toxic cargoes, column o) | at least 31 |
| IBC work time per set in a gas-filled space | at least 20 min1 |
| IBC spare air alternative per breathing apparatus | at least 6,000 l free air1 |
| IGC complete sets of safety equipment | at least 32 |
| IGC SCBA capacity per set | at least 1,200 l free air2 |
| Escape sets, IBC and IGC | at least 15 min, not filter type12 |
| Breathing apparatus checks, IBC and IGC | monthly by officer, yearly by expert or competent person12 |
| Leak test example (Dräger CPS 5900): fill / test start / test time / max drop | 17.5 mbar / 16.5 mbar / 6 min / 3 mbar4 |
| Suit valve test example | 10 mbar, 1 min, less than 1 mbar change4 |
| Material life example (unused) | at least 10 years4 |
What inspectors find
These are the points surveyors and inspectors check against the rules above:
- Fewer complete sets of safety equipment than the IBC or IGC Code requires, or sets missing a component such as the lifeline or explosion-proof lamp.12
- Suits that are not gastight on a gas carrier whose cargo list triggers IGC 14.4.4.2
- No record of monthly breathing apparatus inspections or of the annual expert test.12
- Protective equipment stored in cabins or accommodation corridors, contrary to IBC 14.1.2.1
- Decontamination showers or eyewash that do not work, or freeze, contrary to IBC 14.3.4.1
- Gas-tight suits with no leak test record, past the maker’s interval, or past the maker’s service life.4
FAQ
Are the gas-tight suits the same as the fire-fighter's outfits?
No. Both Codes require the safety equipment sets in addition to the SOLAS fire-fighter’s outfits. A fire-fighter’s suit is built against heat and flame, not chemical permeation.
Can crew do the annual leak test?
Yes, if the maker allows it and the crew have the maker’s test kit and training. Keep the record against the suit’s serial number. Repairs are a different matter: many makers allow only their own or authorised service centres to replace visors, gloves or zips.
Does a suit that passes the leak test resist every chemical?
No. The leak test proves the suit is tight against air leaking out. Resistance to a particular chemical depends on the material, which the maker shows in its permeation data. Check that data against the ship’s cargo list.
Quiz6 questions
Sources
- 1
IMO Resolution MSC.176(79), 2004 amendments to the IBC Code (adopted 10 December 2004, in force 1 January 2007), Annex, chapter 14, paragraphs 14.1 to 14.3. https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MSCResolutions/MSC.176(79).pdf
- 2
IMO Resolution MSC.370(93), Amendments to the IGC Code (adopted 22 May 2014; applies to gas carriers constructed on or after 1 July 2016), Annex, chapter 14, paragraphs 14.1 to 14.4. https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MSCResolutions/MSC.370(93).pdf
- 3
EN 943-1:2015+A1:2019, Protective clothing against dangerous solid, liquid and gaseous chemicals: Part 1, Performance requirements for Type 1 (gas-tight) chemical protective suits; and EN 943-2:2019, Part 2, Type 1 suits for emergency teams (ET); type definitions as published in the standard’s scope (summary by the Swedish Institute for Standards). https://sis.se/en/produkter/environment-health-protection-safety/protective-equipment/protective-clothing/ssen9431
- 4
Dräger, Instructions for use, Dräger CPS 5900 gas-tight chemical protective suit, sections 5 to 8 (maintenance table, leak test, suit valve test, storage, life span). Distributor copy: https://en.gazdetect.com/media/catalog/product/instruction/Manuel-technique-CPS_5900-Dr_ger-EN.pdf
- 5
IMO Resolution MSC.581(110), Revised recommendations for entering enclosed spaces aboard ships (adopted 27 June 2025), Annex, sections 6.8, 9.5 and 10.1.2. https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MSCResolutions/MSC.581(110).pdf
Rules checked 20 October 2026. VSL Safety is not an approved training provider and doesn't issue certificates. These lessons don't replace STCW training, or the manufacturer's training and certification that service technicians need.
