122 
(6) A Certificate issued to a ship shall cease to be valid upon transfer of such 
a ship to the flag of another State, except as provided in paragraph (7) of this 
Regulation. 
(7) Upon transfer of a ship to the flag of another Party, the Certificate shall 
remain in force for a period not exceeding five months provided that it would 
not have expired before the end of that period, or until the Administration 
issues a replacement certificate, whichever is earlier. As soon as possible after 
the transfer has taken place the Government of the Party whose flag the ship 
was formerly entitled to fly shall transmit to the Administration a copy of the 
Certificate carried by the ship before the transfer and, if available, 2 copy of 
the relevant survey report. , 
Regulation 13 
REQUIREMENTS FOR MINIMIZING ACCIDENTAL POLLUTION 
(1) The design, construction, equipment aad operation of ships carrying 
noxious liquid substances in bulk which are subject to the provisions of this 
Annex shall be such as to minimize the uncontrolled discharge into the sea of 
such substances. 
(2) Pursuant to the provisions of paragraph (1) of this Regulation, the 
Government of each Party shall issue, or cause to be issued, detailed require- 
ments on the design, construction, equipment and operation of such ships. 
(3) In respect of chemical tankers, the requirements referred to in para- 
graph (2) of this Regulation shall contain at least all the provisions given in 
the Code for the Construction and Equipment of Ships carrying Dangerous 
Chemicals in Bulk adopted by the Assembly of the Organization in Resolution 
A.212(VII) and as may be amended by the Organization, provided that the 
amendments to that Code are adopted and brought into force in accordance with 
the provisions of Article 17 of the present Convention for amendment procedures 
to an Appendix to an Annex. 
Appendia I 
GUIDELINES FOR THE CATEGORIZATION OF Noxious Liquip SUBSTANCES 
Category A.—Substances which are bioaccumulated and liable to produce a 
hazard to aquatic life or human health; or which are highly toxic to aquatic 
life (as expressed by a Hazard Rating 4, defined by a TLm less than 1 ppm) ; and 
additionally certain substances which are moderately toxie to aquatie life (as 
expressed by a Hazard Rating 3, defined by a TLm of 1 or more, but less than 
10 ppm) when particular weight is given to additional factors in the hazard 
profile or to special characteristics of the substance. 
Category B.—Substances which are bioaccumulated with a short retention of 
the order of one week or less; or which are liable to produce tainting of the sea 
food; or which are moderately toxic to aquatic life (as expressed by a Hazard 
Rating 3, defined by a TLm of 1 ppm or more, but less than 10 ppm); and 
additionally certain substances which are slightly toxic to aquatic life (as 
expressed by a Hazard Rating 2, defined by a TILm of 10 ppm or more, but less 
than 100 ppm) when particular weight is given to additional factors in the 
hazard profile or to special characteristics of the substance. 
Category C._—Substances which are slightly toxic to aquatic life (as expressed 
by a Hazard Rating 2, defined by a TLm of 10 or more, but less than 100 ppm) ; 
and additionally certain substances which are practically non-toxic to aquatic 
life (as expressed by a Hazard Rating 1, defined by a TLm of 100 ppm or more, 
but less than 1,000 ppm) when particular weight is given to additional factors 
in the hazard profile or to special characteristics of the substance. 
Category D.—Substanees which are practically non-toxic to aquatic life (as 
expressed by a hazard rating 1, defined by a TLm of 100 ppm or more, but less 
than 1,000 ppm); or causing deposits blanketing the seafloor with a high bio- 
chemical oxygen demand (BOD): or highly hazardous to human health, with 
an LDs of less than 5 mg/kg; or produce moderate reduction of amenities 
beeause of persistency, smell or poisonous or irritant characteristics, possibly 
interfering with use of beaches; or moderately hazardous to human health, with 
an LDso of 5 mg/kg or more, but less than 50 mg/kg and produce slight reduction 
of amenities. 
Other Liquid Substances (for the purposes of Regulation 4 of this Annex).— 
Substances other than those categorized in Categories A, B, © and PD above. 
