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WHO FOOD ADDITIVES SERIES: 49

Toxicological evaluation of certain
veterinary drug residues in food

ANNEX 4

Recommendations on compounds on the agenda and fuRther information required

Anthelminthic agents

Doramectin

Acceptable daily intake:

0–1 µg/kg bw

Residues:

The MRLs that were recommended at the forty-fifth and fifty-second meetings (WHO TRS 864, 1996, and WHO TRS 893, 2000, respectively) were not reconsidered and were maintained.

Ivermectin

Acceptable daily intake:

0–1 µg/kg bw (established at the fortieth meeting of the Committee (WHO TRS 832, 1993))

Residue definition:

Ivermectin B1a

Recommended maximum residue limits (MRLs)a

Species

Milk
(µg/kg)

Cattle

10

a

The MRLs that were recommended at the thirty-sixth and fortieth meetings of the Committee (WHO TRS 799 (1990) and 832 (1993), respectively) were not reconsidered and were maintained.

Tiabendazole (thiabendazole)

Acceptable daily intake:

0–100 µg/kg bw (established at the fortieth meeting of the Committee (WHO TRS 832, 1993))

Acute reference dose:

100 mg/kg bw

Residues:

The MRLs that were recommended at the fortieth meeting (WHO TRS 832, 1993) were not reconsidered and were maintained.

Antimicrobial agents

Cefuroxime

Acceptable daily intake:

0–30 µg/kg bw (temporary)a

Residue definition:

Cefuroxime

Recommended maximum residue limits (MRLs)

Species

Milk
(µg/kg)

Cattle

50b

a

Results of studies to (1) identify the residues in milk and clarify whether the residues other than parent compound are due primarily to metabolism or to non-metabolic decomposition of parent cefuroxime; and (2) characterize the toxicological significance of non-parent residue in milk are required for evaluation in 2004.

b

The recommended MRL is temporary because the ADI is temporary.

Dihydrostreptomycin and streptomycin

Acceptable daily intake:

0–50 µg/kg bw (group ADI for dihydrostrepto-mycin and streptomycin established at the forty-eighth meeting of the Committee (WHO TRS 879, 1998))

Residue definition:

Sum of the concentrations of dihydrostrepto-mycin and streptomycin

Recommended maximum residue limits (MRLs)a

Species

Milk
(µg/kg)

Cattle

200

Sheep

200

a

The MRLs that were recommended at the fifty-second meeting of the Committee (WHO TRS 893, 2000) were not reconsidered and were maintained.

Lincomycin

Acceptable daily intake:

0–30 µg/kg bw (established at the fifty-fourth meeting of the Committee (WHO TRS 900, 2001))

Residue definition:

Lincomycin

Recommended maximum residue limits (MRLs)a

Species

Muscle
(µg/kg)

Liver
(µg/kg)

Kidney
(µg/kg)

Fat
(µg/kg)

Milk
(µg/kg)

Cattle

 

 

 

 

150

Pigs

200

500

1500

100

 

Chickens

200

500

500

100

 

a

The temporary MRLs for muscle, liver, kidney and fat of cattle and sheep that were recommended at the fifty-fourth meeting of the Committee (WHO TRS 900, 2001) were not extended.

b

The MRLs for fat that were recommended at the fifty-fourth meeting of the Committee were maintained. A separate MRL of 300 mg/kg for skin with adhering fat in pigs was recommended in order to reflect the high concentrations found in the skin of pigs. For consistency, an MRL of 300 mg/kg for skin with adhering fat in chickens was also recommended.

Neomycin

Acceptable daily intake:

0–60 mg/kg bw (established at the forty-seventh meeting of the Committee (WHO TRS 876,1998))

Residues:

Following a request by the Codex Committee on Residues of Veterinary Drugs in Foods at its Twelfth Session (ALINORM 01/31, paragraph 90) the Committee considered information on the registration of injectable neomycin products as well as how they were used with respect to Good Practice in the Use of Veterinary Drugs. In addition, a proposal from the sponsor to increase the MRL in milk was considered. The Committee noted that neomycin for injectable administration had been withdrawn in some countries and was under review in others. The Committee also considered information about the toxicity of neomycin in calves; however, it concluded that toxicity in target animals represents an animal welfare issue that falls outside its mandate. The Committee concluded that there was insufficient justification for changing the MRLs and maintained the MRLs that were recommended at the forty-third, forty-seventh, and fifty-second meetings (WHO TRS 855, 1995, WHO TRS 876, 1998, and WHO TRS 893, 2000, respectively). The Committee recommended that these MRLs be reviewed when the toxicity of neomycin is re-evaluated in response to the request of the Codex Committee on Residues of Veterinary Drugs in Foods at its Thirteenth Session (ALINORM 03/31, paragraph 18).

Oxytetracycline

Acceptable daily intake:

0–30 µg/kg bw (group ADI for tetracycline, oxytetracycline and chlortetracycline; established at the fiftieth meeting of the Committee (WHO TRS 888, 1999))

Residue definition:

Oxytetracycline, expressed as parent drug

Recommended maximum residue limits (MRLs)a

Species

Muscle
(µg/kg)

Fish

200b

a

The MRLs that were recommended in cattle, pigs, sheep, poultry, and giant tiger prawn (Penaeus monodon) at the fiftieth meeting of the Committee (WHO TRS 888, 1999) were not reconsidered and were maintained.

b

The MRL applies only to oxytetracycline.

Thiamphenicol

Acceptable daily intake:

0–5 µg/kg bw (established at the fifty-second meeting of the Committee (WHO TRS 893, 2000))

Residues:

The temporary MRLs in muscle, liver, kidney and fat of pigs and muscle of fish were not extended because the information requested at the fifty-second meeting (WHO TRS 893, 2000) was not provided.

Insecticides

Cyhalothrin

Acceptable daily intake:

0–2 µg/kg bw (temporary)a

Residue definition:

Cyhalothrin

Recommended maximum residue limits (MRLs)b

Species

Muscle
(µg/kg)

Liver
(µg/kg)

Kidney
(µg/kg)

Fat
(µg/kg)

Milk
(µg/kg)

Cattle

20

20

20

400

30

Pigs

20

20

20

400

 

Sheep

20

20

20

400

 

a

Results of appropriate studies to establish a no-observed-effect level (NOEL) for neurobehavioral effects in laboratory animals are required for evaluation in 2004.

b

The recommended MRLs are temporary because the ADI is temporary. In addition, results of the validation of the analytical method for sheep liver to demonstrate a limit of quantification of 10 mg/kg are required for evaluation in 2004.

Cypermethrin

Acceptable daily intake:

0–50 µg/kg bw (established at the forty-seventh meeting of the Committee (WHO TRS 876, 1998))

Residue definition:

Cypermethrin

Recommended maximum residue limits (MRLs)a

Species

Muscle
(µg/kg)

Liver
(µg/kg)

Kidney
(µg/kg)

Fat
(µg/kg)

Sheep

20

20

20

200

a

The ADI established at the forty-seventh meeting (WHO TRS 876, 1998) was for a 45:55 cis:trans mixture. Information provided to the Committee at the present meeting was for an 80:20 cis:trans mixture for topical use. Because the cis isomer is more toxic than the trans isomer, the Committee compared the theoretical maximum daily intake of the 80:20 cis:trans mixture with the ADI for -cypermethrin, which consists only of cis isomers.

alpha-Cypermethrin

Acceptable daily intake:

0–20 µg/kg bw (established at the forty-seventh meeting of the Committee (WHO TRS 876, 1998))

Residue definition:

alpha-Cypermethrin

Recommended maximum residue limits (MRLs)

Species

Muscle
(µg/kg)

Liver
(µg/kg)

Kidney
(µg/kg)

Fat
(µg/kg)

Milk
(µg/kg)

Cattle

100

100

100

1000

100

Sheep

100

100

100

1000

 

Phoxim

Acceptable daily intake:

0–4 mg/kg bw (established at the fifty-second meeting of the Committee (WHO TRS 893, 2000))

Residue definition:

Phoxim

Recommended maximum residue limits (MRLs)

Species

Muscle
(µg/kg)

Liver
(µg/kg)

Kidney
(µg/kg)

Fat
(µg/kg)

Milk
(µg/kg)

Cattlea

50

50

50

400

10

Pigs

50

50

50

400

 

Goats

50

50

50

400

 

Sheep

50

50

50

400

 

a

Temporary MRLs, pending the receipt of information on a GLP-compliant study on residue depletion in cattle, which is required for evaluation in 2004

Production aid

Melengestrol acetate

Acceptable daily intake:

0–0.03 µg/kg bw (established at the fifty-fourth meeting of the Committee (WHO TRS 900, 2001))

Residue definition:

Melengestrol acetate

Recommended maximum residue limits (MRLs)

Species

Liver
(µg/kg)

Fat
(µg/kg)

Cattle

2

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    See Also:
       Toxicological Abbreviations