7 The complete text of chapter 21 is replaced by the following:
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Resolutions - Marine Environment Protection Committee - Resolution MEPC.318(74) - Amendments to the International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (IBC Code) - (Amendments to Chapters 1, 15, 16, 17, 18, 19 and 21) - (adopted on 17 May 2019) - Annex - Amendments to the International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (IBC Code) - 7 The complete text of chapter 21 is replaced by the following:

7 The complete text of chapter 21 is replaced by the following:

"Chapter 21 Criteria for assigning carriage requirements for products subject to the IBC Code

21.1 Introduction

21.1.1 The following criteria are used for the determination of pollution classification and assignment of appropriate carriage requirements for bulk liquid cargoes being assessed for entry into the IBC Code or lists 1, 3 or 4 of the MEPC.2/Circular.

21.1.2 In developing such criteria, every effort has been made to follow the criteria and cut-off points developed under the Globally Harmonized System (GHS).

21.1.3 Although the criteria are intended to be closely defined in order to establish a uniform approach, it must be emphasized that where human experience or other factors indicate the need for alternative arrangements, these shall always be taken into account. Where deviations from the criteria have been recognized, they shall be properly recorded with justifications.

21.2 Contents

21.2.1 This chapter contains the following:

  • .1 minimum safety and pollution criteria for products subject to chapter 17 of the IBC Code;

  • .2 criteria used to assign the minimum carriage requirements for products that meet the safety or pollution criteria to make them subject to chapter 17 of the IBC Code;

  • .3 criteria used for determining special requirements in chapter 15 of the IBC Code to be included in column o of chapter 17 of the IBC Code;

  • .4 criteria used for determining special requirements in chapter 16 of the IBC Code to be included in column o of chapter 17 of the IBC Code;

  • .5 definitions of properties used within this chapter;

  • .6 information on the use of the GESAMP Hazard Ratings; and

  • .7 information on the application of the SVC/LC50 ratio method.

21.2.2 The information included in parentheses following the classification criteria throughout this chapter refers to the GESAMP Hazard Profile ratings set out in appendix I of MARPOL Annex II under the "Abbreviated legend to the revised GESAMP Hazard Evaluation procedure". The full listing of GESAMP Hazard Profile ratings for evaluated substances are published annually in the GESAMP Composite List as a PPR Circular. It should be noted that ratings in parentheses (based on estimation methods applied by GESAMP) are considered as equivalent to ratings without parentheses for the purpose of assigning carriage requirements.

21.3 Minimum safety and pollution criteria for products subject to chapter 17 of the IBC Code

21.3.1 Products are deemed to be hazardous and subject to chapter 17 of the IBC Code if they meet one or more of the following criteria:

  • .1 inhalation LC50/ATE ≤ 20 mg/L/4h (see paragraph 21.7.1.3) (C3 = 1, 2, 3 or 4);

  • .2 dermal LD50/ATE ≤ 2000 mg/kg (see paragraph 21.7.1.2) (C2 = 1, 2, 3, or 4);

  • .3 oral LD50/ATE ≤ 2000 mg/kg (see paragraph 21.7.1.1) (C1 = 1, 2, 3, or 4);

  • .4 toxic to mammals by prolonged exposure (see paragraph 21.7.2) (D3 = C, M, R, N, T, or I);

  • .5 cause skin sensitization (see paragraph 21.7.3) (D3 = Ss);

  • .6 cause respiratory sensitization (see paragraph 21.7.4) (D3 = Sr);

  • .7 corrosive to skin (see paragraph 21.7.5) (D1 = 3, 3A, 3B, or 3C);

  • .8 with a Water Reactive Index (WRI) of ≥ 1 (see paragraph 21.7.6);

  • .9 require inertion, inhibition, stabilization, temperature control or tank environmental control in order to prevent a hazardous reaction (see definitions in paragraph 21.7.10);

  • .10 flashpoint < 23°C; and have an explosive/flammability range (expressed as a percentage by volume in air) of ≥ 20%;

  • .11 auto-ignition temperature of ≤ 200°C; and

  • .12 classified as pollution category X or Y or meeting the criteria for rules 11 to 13 in table 2 in paragraph 21.4.5.2.

21.4 Criteria used to assign the minimum carriage requirements for products that meet the minimum safety or pollution criteria to make them subject to chapter 17 of the IBC Code

21.4.1 Column a – Product name

21.4.1.1 A standardized chemical name, preferably assigned on the basis of the Chemical Abstracts Service (CAS) or the International Union of Pure and Applied Chemistry (IUPAC) system, shall be used as far as possible. However, where this is unnecessarily complex, then a technically correct and unambiguous alternative name may be used.

21.4.2 Column b – Deleted

21.4.3 Column c – Pollution category

21.4.3.1 Column c identifies the pollution category assigned to each product in accordance with MARPOL Annex II, based on table 1 below (see MARPOL Annex II, appendix I).

Table 1 – Guidelines for the categorization of Noxious Liquid Substances

Rule A1

Bio- accumulation

 A2

Bio- degradation

 B1

Acute toxicity

 B2

Chronic toxicity

 D3

Long-term health effects

 E2

Effects on marine wildlife and on benthic habitats

 Cat
1 ≥ 5 X
2 ≥ 4 4
3 NR 4
4 ≥ 4 NR CMRTNIfootnote
5 4 Y
6 3
7 2
8 ≥ 4 NR Not 0
9 ≥ 1
10 Fp, F or S If not Inorganic
11 CMRTNIfootnote
12 Any product not meeting the criteria of rules 1 to 11 and 13 Z
13 All products identified as: ≤ 2 in column A1; R in column A2; blank in column D3; not Fp, F or S (if not organic) in column E2; and 0 (zero) in all other columns of the GESAMP Hazard Profile OS

21.4.4 Column d – Hazards

21.4.4.1 An "S" is assigned to column d if any of the safety criteria described in paragraphs 21.3.1.1 to 21.3.1.11 are met.

21.4.4.2 A "P" is assigned to column d if the product meets the criteria for assigning Ship Type 1 to 3 as defined by rules 1 to 14 in the table 2.

21.4.5 Column e – Ship Type

21.4.5.1 Assignment of Ship Types is carried out from both a pollution and safety perspective. The basic criteria for assigning Ship Types from a pollution perspective is carried out based on the GESAMP Hazard Profile, shown in table 2. An explanation of the details in the columns is provided in appendix I of MARPOL Annex II.

21.4.5.2 The following criteria are used to assign the Ship Type:

  • Ship Type 1:

    • Inhalation LC50/ATE≤ 0.5 mg/L/4h (C3 = 4) and SVC/LC50 ≥ 20; and/or
    • Dermal LD50/ATE ≤ 50 mg/kg (C2 = 4); and/or
    • WRI = 3; and/or
    • Auto-ignition temperature ≤ 65℃; and/or
    • Explosive range ≥ 50% v/v in air and the flashpoint < 23°C; and/or
    • Rules 1 or 2 of the table 2 shown in 21.4.5.2 (below).

  • Ship Type 2:

    • Inhalation LC50/ATE ≤ 0.5 mg/L/4h (C3 = 4) and SVC/LC50 < 20; or
    • Inhalation LC50/ATE > 0.5 mg/L/4h – ≤ 2mg/L/4h (C3 = 3) and SVC/LC50 ≥ 2 (see note); and/or
    • Dermal LD50/ATE > 50 mg/kg – ≤ 200 mg/kg (C2 = 3); and/or WRI = 2; and/or
    • Auto-ignition temperature ≤ 200oC; and/or
    • Explosive range ≥ 40% v/v in air and the flashpoint < 23°C; and/or
    • Any product meeting the criteria of rules 3 to 10 in table 2.

    • Note: Products with a density >1025 kg/m3 (sinkers) or a water solubility of >50% (dissolvers) that are assigned to Ship Type 2 based on the inhalation toxicity criteria, may be re-assigned to Ship Type 3.

  • Ship Type 3:
    • Any of the minimum safety or pollution criteria for bulk liquid cargoes subject to chapter 17 of the IBC Code not meeting the requirements for Ship Types 1 or 2 and not meeting rule 15 of table 2 shown in 21.4.5.2 (below).

Table 2 – Assignment of Ship Types based on the GESAMP Hazard Profile

Rule A1 A2 B1 B2 D3 E2 Ship Type
1 ≥ 5 1
2 ≥ 4 NR 4 CMRTNIfootnote
3 ≥ 4 NR CMRTNIfootnote 2
4 4
5 ≥ 4 3
6 NR 3
7 ≥ 1
8 Fp
9 CMRTNIfootnote F
10 ≥ 2 S
11 ≥ 4 3
12 NR
13 ≥ 1
14 All other category Y Substances
15 All other category Z Substances All "Other Substances" (OS) NA

21.4.6 Column f – Tank type

21.4.6.1 The tank type is assigned according to the following criteria:

Tank type 1G: Inhalation LC50/ATE ≤ 0.5 mg/L/4h (C3 = 4) and SVC/LC50 ≥ 1000; and/or

Dermal LD50/ATE ≤ 50 mg/kg (C2 = 4); and/or;

WRI=3; and/or

Auto-ignition temperature ≤ 65oC; and/or

Explosive range ≥ 40% v/v in air and the flashpoint < 23oC.

Based on expert judgement, tank type 1G may be required for specific products (e.g. for molten sulphur, hydrochloric acid)

Tank type 2G: Any of the minimum safety or pollution criteria for bulk liquid cargoes subject to chapter 17 or the IBC Code not meeting the requirements for tank type 1G.

21.4.7 Column g – Tank vents

21.4.7.1 The tank venting arrangements are assigned according to the following criteria:

  • Controlled:
 Inhalation LC50/ATE ≤ 10 mg/L/4h (C3 = 2, 3 or 4), unless in accordance with 21.7.12; and/or

Toxic to mammals by prolonged exposure (D3 = C, M, R, T, N, or I); and/or

Respiratory sensitizer (D3 = Sr, see also paragraph 21.7.4); and/or

Special carriage control needed; and/or

Flashpoint ≤ 60oC; and

Corrosive to skin (≤ 4h exposure). (D1 = 3A, 3B, or 3C).

  • Open:
 Any of the minimum safety or pollution criteria for bulk liquid cargoes subject to chapter 17 or the IBC Code not meeting the requirements for controlled tank vents.

21.4.8 Column h – Tank environmental control

21.4.8.1 The tank environmental control conditions are assigned according to the following criteria:

  • Inert:
 Auto-ignition temperature ≤ 200C; and/or Reacts with air to cause a hazard; and/or Explosive range ≥ 40% and the flashpoint < 23°C.
  • Dry:
 WRI > 1
  • Pad:
 Only applies to specific products identified on a case by case basis.
  • Vent:
 Only applies to specific products identified on a case by case basis.
  • No:
 Where the above criteria do not apply (inerting requirements may be required under SOLAS).

21.4.9 Column i – Electrical equipment

21.4.9.1 If the flashpoint of the product is ≤ 60oC or the product is heated to within 15oC of its flashpoint then the electrical equipment required are assigned according to the following criteria, otherwise "–" is assigned in column i' and i":
  • .1 Column i' – Temperature class:
    • T1 Auto-ignition temperature ≥ 450oC
      T2 Auto-ignition temperature ≥ 300oC but < 450oC
      T3 Auto-ignition temperature ≥ 200oC but < 300oC
      T4 Auto-ignition temperature ≥ 135oC but < 200oC
      T5 Auto-ignition temperature ≥ 100oC but < 135oC
      T6 Auto-ignition temperature ≥ 85oC but < 100oC

  • .2 Column i'' – Apparatus group:

    • Apparatus group MESG at 20oC (mm) MIC ratio product/methane
      IIA > 0.90 > 0.80
      IIB > 0.50 to ≤ 0.90 > 0.45 to ≤ 0.80
      IIC ≤ 0.50 ≤ 0.45

    • .1 The tests shall be carried out in accordance with the procedures described in IEC 60079-1-1:2002 and IEC 79-3.

    • .2 For gases and vapours it is sufficient to make only one determination of either the Maximum Experimental Safe Gap (MESG) or the Minimum Igniting Current (MIC) provided that:
      • for Group IIA: the MESG > 0.90 mm or the MIC ratio > 0.80
        for Group IIB: the MESG is > 0.50 mm and ≤ 0.90 mm; or

        the MIC ratio is > 0.50 and ≤ 0.80

        for Group IIC: the MESG is ≤ 0.50 mm or the MIC ratio is ≤ 0.45
    • .3 It is necessary to determine both the MESG and the MIC ratio when:

      • .1 The MIC ratio determination only has been made, and the ratio is between 0.80 and 0.90, when an MESG determination will be required;

      • .2 The MIC ratio determination only has been made, and the ratio is between 0.45 and 0.50, when an MESG determination will be required; or

      • .3 The MESG only has been found, and is between 0.50 mm and 0.55 mm, when an MIC ratio determination will be required.

    • .3 Column i"' Flashpoint:
      • > 60°C Yes
        ≤ 60°C No
        Non-flammable NF

21.4.10 Column j – Gauging

21.4.10.1 The gauging equipment is assigned according to the following criteria:

  • Closed:

    Inhalation LC50/ATE ≤ 2 mg/L/4h (C3 = 3 or 4), unless in accordance with 21.7.12; and/or

    Dermal LD50/ATE ≤ 1000 mg/kg (C2 = 2, 3 or 4); and/or

    Toxic to mammals by prolonged exposure (D3 = C, M, R, T, N, or I); and/or

    Respiratory sensitizer (D3 = Sr, see also paragraph 21.7.4); and/or Severely corrosive to skin (≤ 3 min exposure) (D1= 3C).

    Restricted:

    Inhalation LC50/ATE >2 - ≤10 mg/L/4h (C3 = 2), unless in accordance with 21.7.12; and/or

    Special carriage control indicates inerting required; and/or

    Highly corrosive to skin (> 3 min - ≤1h exposure) (D1 = 3B); and/or Flashpoint ≤ 60oC.

    Open:

    Any of the minimum safety or pollution criteria for bulk liquid cargoes subject to chapter 17 or the IBC Code not meeting the requirements for closed or restricted gauging.

21.4.11 Column k – Vapour detection

21.4.11.1 The vapour detection equipment is assigned according to the following criteria:
  • Toxic (T): Inhalation LC50/ATE ≤ 10 mg/L/4h (C3 = 2, 3, or 4), unless in accordance with 21.7.12, and/or

    Respiratory sensitizer (D3 = Sr, see also paragraph 21.7.4); and/or

    Toxic to mammals by prolonged exposure (D3 = C, M, R, T, N, or I)

    Flammable (F): Flashpoint ≤ 60oC
    No (No): Where the above criteria do not apply

21.4.12 Column l – Fire protection equipment

21.4.12.1 The appropriate fire-fighting media are defined as being appropriate according to the following criteria related to the properties of the product:
  • Solubility > 10% (> 100000 mg/L) A Alcohol-resistant foam
    Solubility ≤ 10% (≤ 100000 mg/L) A Alcohol-resistant foam; and/or
      B Regular foam
    WRI = 0 C Water spray (generally used as a coolant and can be used with A and/or B providing that the WRI = 0)
    WRI ≥1 D Dry chemical
      No No requirements under this Code. This applies where a product as identified as NF in column i''' (see paragraph 21.4.9.1.3).

    Note: all appropriate media shall be listed.

21.4.13 Column m – Deleted

21.4.14 Column n – Emergency equipment

21.4.14.1 The requirement to have personnel emergency equipment on board is identified by "Yes" in column n according to the following criteria:

  • Inhalation LC50/ATE ≤ 2 mg/L/4h (C3 = 3 or 4); unless in accordance with 21.7.12 and/or
  • Respiratory sensitizer (D3 = Sr, see also paragraph 21.7.4); and/or
  • Severely corrosive to skin (≤ 3 min exposure) (D1 = 3C); and/or
  • WRI = 2

  • No: indicates that the above criteria do not apply.

21.5 Column o – Criteria for special requirements in chapter 15

21.5.1 The assignment of special requirements in column o shall normally follow clear criteria based on the data supplied in the reporting form. Where it is considered appropriate to deviate from such criteria, this shall be clearly documented in such a way that it can easily be retrieved on demand.

21.5.2 The criteria for making reference to the special requirements identified in chapters 15 and 16 are defined below with comments where relevant.

21.5.3 Paragraphs 15.2 to 15.10 and 15.20

21.5.3.1 Paragraphs 15.2 to 15.10 and 15.20 identify specific products by name with special carriage requirements that cannot be easily accommodated in any other way.

21.5.4 Paragraph 15.11 – Acids

21.5.4.1 Paragraph 15.11 applies to all acids unless they:

  • .1 are organic acids – when only paragraphs 15.11.2 to 15.11.4 and paragraphs 15.11.6 to 15.11.8 apply; or

  • .2 do not evolve hydrogen – when paragraph 15.11.5 need not apply.

21.5.5 Paragraph 15.12 – Toxic products

21.5.5.1 All of paragraph 15.12 is added to column o according to the following criteria:

  • Inhalation LC50/ATE ≤ 2 mg/L/4h (C3 = 3 or 4), unless in accordance with 21.7.12; and/or
  • the product is a respiratory sensitizer (D3 = Sr, see also paragraph 21.7.4); and/or
  • the product is toxic to mammals by prolonged exposure (D3 = C, M, R, T, N, or I).

21.5.5.2 Paragraphs 15.12.3 and 15.12.4 are added to column o according to the following criterion:

  • Inhalation LC50/ATE > 2 - ≤ 10 mg/L/4h (C3 = 2), unless in accordance with 21.7.12.

21.5.5.3 Paragraph 15.12.3.2 is added to column o according to the following criteria:

  • Dermal LD50/ATE ≤ 1000 mg/kg (C2 = 2, 3, or 4); and/or
  • Oral LD50/ATE ≤ 300 mg/kg (C1 = 2, 3, or 4).

21.5.6 Paragraph 15.13 – Cargoes protected by additives

21.5.6.1 The requirement to assign paragraph 15.13 to column o is based on the information related to the product's tendency to polymerize, decompose, oxidize or undergo other chemical changes which may cause a hazard under normal carriage conditions, but which would be prevented by the addition of appropriate additives.

21.5.7 Paragraph 15.14 – Cargoes with a vapour pressure greater than atmospheric at 37.8°C

21.5.7.1 The requirement to assign paragraph 15.14 to column o is based on the following criterion:

  • Boiling point ≤ 37.8oC

21.5.8 Paragraph 15.16 – Cargo contamination

21.5.8.1 Paragraph 15.16.1 is deleted.

21.5.8.2 Paragraph 15.16.2 is added to column o according to the following criterion:

  • WRI>1

21.5.9 Paragraph 15.17 – Increased ventilation requirements

21.5.9.1 Paragraph 15.17 shall be added to column o according to the following criteria:

  • Inhalation LC50/ATE > 0.5 - ≤ 2 mg/L/4h (C3 = 3), unless in accordance with 21.7.12; and/or

  • Respiratory sensitizer (D3 = Sr, see also paragraph 21.7.4); and/or

  • Toxic to mammals by prolonged exposure (D3 = C, M, R, T, N, or I); and/or

  • Highly to severely corrosive to skin (≤ 1h exposure time) (D1 = 3B or 3C).

21.5.10 Paragraph 15.18 – Special cargo pump-room requirements

21.5.10.1 Paragraph 15.18 shall be added to column o according to the following criterion: Inhalation LC50/ATE ≤ 0.5 mg/L/4h (C3 = 4), unless in accordance with 21.7.12

21.5.11 Paragraph 15.19 – Overflow control

21.5.11.1 Paragraph 15.19 shall be added to column o according to the following criteria:

  • Inhalation LC50/ATE ≤ 2 mg/L/4h (C3 = 3 or 4), unless in accordance with 21.7.12; and/or
  • Dermal LD50/ATE ≤ 1000 mg/kg (C2 = 2, 3, or 4); and/or Oral LD50/ATE ≤ 300 mg/kg (C1 = 2, 3, or 4); and/or Respiratory sensitizer (D3 = Sr, see also paragraph 21.7.4); and/or
  • Severely corrosive to skin (≤ 3 min exposure) (D1 = 3C); and/or
  • Auto-ignition temperature ≤ 200oC; and/or
  • Explosive range ≥ 40% v/v in air and flashpoint < 23°C; and/or
  • Classified as Ship Type 1 on pollution grounds.

21.5.11.2 Only paragraph 15.19.6 shall apply if the product has any of the following properties:

  • Inhalation LC50/ATE > 2 mg/L/4h - ≤10 mg/L/4h (C3 = 2), unless in accordance with 21.7.12; and/or
  • Dermal LD50/ATE > 1000 mg/kg - ≤ 2000 mg/kg (C2 = 1); and/or
  • Oral LD50/ATE > 300 mg/kg - ≤ 2000 mg/kg (C1 = 1); and/or
  • Skin sensitizer (D3=Ss); and/or
  • Highly corrosive to skin (> 3 min - ≤ 1h exposure) (D1 = 3B); and/or
  • Flashpoint ≤ 60oC; and/or
  • Classified as Ship Type 2 on pollution grounds; and/or
  • Pollution category X or Y.

21.5.12 Paragraph 15.21 – Temperature sensors

21.5.12.1 Paragraph 15.21 is added to column o according to the heat sensitivity of the product. This requirement is related to pumps in cargo pump-rooms only.

21.6 Column o – Criteria for special requirements in chapter

16 21.6.1 Paragraphs 16.1 to 16.2.5 and 16.3 to 16.5

21.6.1.1 These apply to all cargoes and so are not referenced specifically in column o.

21.6.2 Paragraph 16.2.6

21.6.2.1 Paragraph 16.2.6 is added to column o for products, which meet the following criteria: Pollution Category X or Y and viscosity ≥ 50 mPa·s at 20oC.

21.6.3 Paragraph 16.2.9

21.6.3.1 Paragraph 16.2.9 is added to column o for products, which meet the following criterion: Melting point ≥ 0oC.

21.6.4 Paragraph 16.6 – Cargo not to be exposed to excessive heat

21.6.4.1 Paragraphs 16.6.2 to 16.6.4 are added to column o for products, which are identified as requiring temperature control during carriage.

21.6.5 Paragraph 16.2.7 – Persistent floaters

Paragraph 16.2.7 is added to column o for products which meet the following criteria: Pollution Category Y that are persistent floaters (E2 = Fp) with a viscosity greater than or equal to 50 mPa·s at 20ºC and/or with a melting point greater than or equal to 0ºC.

21.7 Definitions

21.7.1 Acute mammalian toxicity

LC50 is the concentration in air, LD50 is the amount (dose) of test substance, which causes mortality to 50% of a test species. ATE refers to a dose (concentration) range or extrapolated dose (concentration) leading to lethal effects in mammals, equivalent to an LC50 or LD50.

21.7.1.1 Acutely toxic if swallowed

Oral toxicity (LD50/ATE) GESAMP Hazard Profile Rating C1
Hazard Level mg/kg
High ≤ 5 4
Moderately High > 5 - ≤ 50 3
Moderate > 50 - ≤ 300 2
Slight > 300 - ≤ 2000 1
Negligible > 2000 0

21.7.1.2 Acutely toxic in contact with skin

Dermal toxicity (LD50/ATE) GESAMP Hazard Profile Rating C2
Hazard Level mg/kg
High ≤ 50 4
Moderately high > 50 - ≤ 200 3
Moderate > 200 - ≤ 1000 2
Slight > 1000 - ≤ 2000 1
Negligible > 2000 0

21.7.1.3 Acutely toxic by inhalation

  • All inhalation toxicity data are assumed to be for vapours and not mists or sprays, unless otherwise indicated.

Inhalation toxicity (LC50/ATE) GESAMP Hazard Profile Rating C3
Hazard level mg/L/4h
High ≤ 0.5 4
Moderately high > 0.5 - ≤ 2 3
Moderate > 2 - ≤ 10 2
Slight > 10 - ≤ 20 1
Negligible > 20 0

21.7.2 Toxic to mammals by prolonged exposure

21.7.2.1 A product is classified as toxic to mammals by prolonged exposure if it meets any of the following criteria: it is known to be, or suspected of being carcinogenic, mutagenic, reprotoxic, neurotoxic, immunotoxic or exposure below the lethal dose is known to cause Specific Target Organ Toxicity.

21.7.2.2 Such effects may be identified from the GESAMP Hazard Profile of the product (D3 = C, M, R, T, N, or I) or other recognized sources of such information.

21.7.3 Skin sensitization

21.7.3.1 A product is classified as a skin sensitizer:

  • .1 if there is evidence in humans that the substance can induce sensitization by skin contact in a substantial number of persons; or

  • .2 where there are positive results from an appropriate test.

21.7.3.2 Such effects are identified in the GESAMP Hazard Profile for the product (D3 = Ss).

21.7.4 Respiratory sensitization

21.7.4.1 A product is classified as a respiratory sensitizer:

  • .1 if there is evidence in humans that the substance can induce specific respiratory hypersensitivity; and/or

  • .2 where there are positive results from an appropriate test; and/or

  • .3 where the product does not have a GESAMP Hazard Profile and is identified as a skin sensitizer and there is no evidence to show that it is not a respiratory sensitizer.

21.7.4.2 Such effects are identified in the GESAMP Hazard Profile for the product (D3 = Sr) or other recognized sources of such information, if no profile exists.

21.7.5 Corrosive to skinfootnote

Hazard Level Exposure time to cause full thickness necrosis of skin GESAMPHazard Profile Rating D1
Severely corrosive to skin ≤ 3 min 3C
Highly corrosive to skin > 3 min - ≤ 1h 3B
Moderately corrosive to skin > 1h - ≤ 4h 3A

Note: A rating of 3 or (3) in the D1 column of the GESAMP Hazard Profile without any additional letter notation (A, B or C), means that the severity of corrosivity has not been established. For such cases, a rating of 3 or (3) is understood to be equivalent to a rating of 3B for the purpose of assigning carriage requirements.

21.7.6 Water reactive substances

21.7.6.1 These are classified as follows:

Water Reactive Index (WRI) Definition
3 Any chemical which is extremely reactive with water and produces large quantities of flammable, toxic or corrosive gas or aerosol
2 Any chemical which, in contact with water, may produce a toxic, flammable or corrosive gas or aerosol
1 Any chemical which, in contact with water, may generate heat or produce a non-toxic, non-flammable or non-corrosive gas
0 Any chemical which, in contact with water, would not undergo a reaction to justify a value of 1, 2 or 3

21.7.7 Air reactive substances

21.7.7.1 Air reactive substances are products that react with air to cause a potentially hazardous situation, e.g. the formation of peroxides that may cause an explosive reaction.

21.7.8 Electrical apparatus – Temperature class

  • (for products which either have a flashpoint of ≤ 60oC or are heated to within 15°C of their flashpoint)
21.7.8.1 The temperature class is defined by the International Electrotechnical Commission (IEC) as:

  • "The highest temperature attained under practical conditions of operation within the rating of the apparatus (and recognized overloads, if any, associated therewith) by any part of any surface, the exposure of which to an explosive atmosphere may involve a risk."

21.7.8.2 The temperature class of the electrical apparatus is assigned by selecting the Maximum Surface Temperature which is closest to, but less than, the product's auto-ignition temperature (see 21.4.9.1.1).

21.7.9 Electrical apparatus – Apparatus group

  • (for products with a flashpoint of ≤ 60oC)
21.7.9.1 This refers to intrinsically safe and associated electrical apparatus for explosive gas atmospheres which the IEC divide into the following groups:

  • Group I: for mines susceptible to firedamp (not used by IMO); and

  • Group II: for applications in other industries – further subdivided according to its Maximum Experimental Safe Gap (MESG) and/or the Minimum Igniting Current (MIC) of the gas/vapour into groups IIA, IIB and IIC.

21.7.9.2 This property cannot be determined from other data associated with the product; it has to be either measured or assigned by assimilation with related products in a homologous series.

21.7.10 Special carriage control conditions

21.7.10.1 Special carriage control conditions refer to specific measures that need to be taken in order to prevent a hazardous reaction. They include:

  • .1 Inhibition: the addition of a compound (usually organic) that retards or stops an undesired chemical reaction such as corrosion, oxidation or polymerization;

  • .2 Stabilization: the addition of a substance (stabilizer) that tends to keep a compound, mixture or solution from changing its form or chemical nature. Such stabilizers may retard a reaction rate, preserve a chemical equilibrium, act as antioxidants, keep pigments and other components in emulsion form or prevent the particles in colloidal suspension from precipitating;

  • .3 Inertion: the addition of a gas (usually nitrogen) in the ullage space of a tank that prevents the formation of a flammable cargo/air mixture;

  • .4 Temperature control: the maintenance of a specific temperature range for the cargo in order to prevent a hazardous reaction or to keep the viscosity low enough to allow the product to be pumped; and

  • .5 Padding and venting: only applies to specific products identified on a case by case basis.

21.7.11 Flammable cargoes

21.7.11.1 A cargo is defined as flammable according to the following criteria:

IBC Code descriptor Flashpoint (degrees Centigrade)
Highly flammable < 23
lammable ≤ 60 but ≥ 23

21.7.11.2 It should be noted that flashpoints of mixtures and aqueous solutions need to be measured unless all of the components are non-flammable.

21.7.11.3 It should be noted that the carriage of bulk liquid cargoes that have a flashpoint of ≤ 60°C are subject to other SOLAS regulations.

21.7.12 Application of the SVC/LC50 ratio method

21.7.12.1 If the vapour pressure and the molecular weight of a substance are known, an estimate of the maximum vapour concentration in a closed compartment (e.g. a tank) can be calculated. This is called the Saturated Vapour Concentration (SVC).

21.7.12.2 The hazard quotient SVC/LC50footnote is a substance specific value for the velocity of a vapour for achieving a hazardous concentration when emerging from a liquid source (e.g. leak, spillage or tank ventilation), and can be used in the assignment of specific carriage requirements related to inhalation toxicity.

21.7.12.3 If a solid substance is transported in an aqueous solution, the vapour pressurefootnote of this solid rather than that of water may be used in the calculation of the SVC/LC50 ratio.

21.7.12.4 Application of the SVC/LC50 ratio for assigning Ship Type and Tank type

21.7.12.4.1 For the assignment of Ship Type and tank type, as set out in paragraph 21.4.5 and 21.4.6, the application of the SVC/LC50 ratio method is optional. Should this method be used, the vapour pressure at 20°C shall be used when calculating the SVC/LC50 ratio.

21.7.12.4.2 The SVC mg/L of a substance should be calculated as follows:

  • where MW is the molecular weight of the substance.

21.7.12.4.3 The SVC/LC50 ratio should be calculated as follows:

21.7.12.5 Application of the SVC/LC50 ratio for assigning carriage requirements

21.7.12.5.1 For the carriage requirements listed in 21.7.12.5.5, the application of the SVC/LC50 ratio method is optional. If the SVC/LC50 ratio method is used in the assignment of these carriage requirements, the vapour pressure at 40°C shall be used when calculating the SVC/LC50 ratio. If the carriage temperature is higher than 40°C, then the SVC/LC50 ratio should be calculated at that temperature.

21.7.12.5.2 The SVC (mg/l) of a substance should be calculated as follows:

where MW is the molecular weight of the substance.

21.7.12.5.3 The SVC/LC50 ratio should be calculated as follows:

21.7.12.5.4 The SVC (mg/L) formula described in 21.7.12.5.2 is standardized for calculations at 40°C. When using the vapour pressure at higher temperatures in the calculations, the formula must be amended accordingly.

21.7.12.5.5 For the following carriage requirements, the SVC/LC50 ratio method, calculated at 40°C or higher, may be used as an alternative to the acute inhalation toxicity criteria given in paragraphs 21.4 and 21.5:

1. Column g – Tank vents
  Assignment of controlled venting is not required based on the inhalation hazard only, if:
  Inhalation LC50/ATE ≤ 10 mg/L/4h (C3 = 2, 3, or 4) and SVC/LC50 < 0.2
2. Column j – Gauging
  Closed gauging is not required based on the inhalation hazard only, if:
  Inhalation LC50/ATE ≤ 2 mg/L/4h (C3 = 3 or 4) and SVC/LC50 < 0.2 but restricted gauging is required.
  Restricted gauging is not required based on the inhalation hazard only, if:
  Inhalation LC50/ATE > 2 - ≤ 10 mg/L/4h (C3 = 2) and SVC/LC50 < 0.2
.3 Column k – Vapour detection
  Assignment of toxic vapour detection is not required based on the inhalation hazard only, if:
  Inhalation LC50/ATE ≤ 10 mg/L/4h (C3 = 2, 3, or 4) and SVC/LC50 < 0.2
4. Column n – Emergency Equipment
  Inhalation LC50/ATE ≤ 2 mg/L/4h (C3 = 3 or 4) and SVC/LC50 < 0.2
5. Column o – Special requirements in chapter 15
  15.12.1 and 15.12.2 are not required based on the inhalation hazard only, if:
  Inhalation LC50/ATE ≤ 2 mg/L/4h (C3 = 3 or 4) and SVC/LC50 < 0.2
  15.12.3 and 15.12.4 are not required based on the inhalation hazard only, if:
  Inhalation LC50/ATE >2 - ≤ 10 mg/L/4h (C3 = 2) and SVC/LC50 < 0.2
  15.17 is not required based on the inhalation hazard only, if:
  Inhalation LC50/ATE ≤ 0.5 mg/L/4h (C3 = 4) and SVC/LC50 < 0.2
  15.18 is not required based on the inhalation hazard only if:
  Inhalation LC50/ATE ≤ 0.5 mg/L/4h (C3 = 4) and SVC/LC50 < 0.2
  15.19 is not required based on the inhalation hazard only, if:
  Inhalation LC50/ATE ≤ 2 mg/L/4h (C3 = 3 or 4) and SVC/LC50 < 0.2, but 15.19.6 applies
  15.19.6 is not required based on the inhalation hazard only, if:
  Inhalation LC50/ATE > 2 - ≤ 10 mg/L/4h (C3 = 2) and SVC/LC50 < 0.2"
Parent topic: Annex - Amendments to the International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (IBC Code)
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