Scientific Opinion on the re-evaluation of Brilliant Black BN (E 151) as a food additive

The Panel on Food Additives and Nutrient Sources added to Food provides a scientific opinion re-evaluating the safety of Brilliant Black BN (E 151). Brilliant Black BN has been previously evaluated by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1975, 1978 and 1981, and the EU Scientific Committee for Food (SCF) in 1984. JECFA established an Acceptable Daily Intake (ADI) of 1 mg/kg bw/day, whereas the SCF established an ADI of 5 mg/kg bw/day. The Panel was not provided with a newly submitted dossier and based its evaluation on previous evaluations, additional literature that became available since then and the data available following a public call for data. In a recent study, Brilliant Black BN was found positive in a micronucleus test and a Comet assay in vitro. However, the Panel noted that Brilliant Black BN was negative in long-term carcinogenicity studies and that the effects on nuclear DNA migration observed in these assays are not expected to result in carcinogenicity. The Panel concluded that the present database does not give reason to revise the ADI of 5 mg/kg bw/day based on a long-term carcinogenicity and toxicity study in rats. The Panel concluded that at the current maximum reported levels of use of Brilliant Black BN, refined intake estimates are generally below the ADI of 5 mg/kg bw/day. However in children under 10 years, the 95th percentile can be 6.9 mg/kg bw/day and thus exceeds the ADI at the upper end of the range.

© European Food Safety Authority, 2010

Following a request from the European Commission to the European Food Safety Authority, the Scientific Panel on Food Additives and Nutrient Sources added to Food was asked to deliver a scientific opinion re-evaluating the safety of Brilliant Black BN (E 151) when used as a food colouring substance.

Brilliant Black BN (E 151) is a bis-azo dye authorised as a food additive in the EU and has previously been evaluated by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1975, 1978 and 1981, and by the EU Scientific Committee for Food (SCF) in 1984. The JECFA and SCF committees have established different Acceptable Daily Intakes (ADI) of 1 and 5 mg/kg bw/day, respectively.

The Panel was not provided with a newly submitted dossier and based its evaluation on previous evaluations and reviews, additional literature that became available since then and the data available following a public call for data. The Panel notes that not all original studies, on which previous evaluations or reviews were based, were available for re-evaluation by the Panel.

The Panel concurs with the view expressed in previous evaluations by JECFA and TemaNord that the absorption of the parent molecule of Brilliant Black BN is limited, but that after azo reduction in the gastrointestinal tract, free sulphonated aromatic amines may reach the systemic circulation.

Long-term carcinogenicity studies on Brilliant Black BN were re-evaluated by the Panel. Several long-term carcinogenicity studies in rats or mice, at dose levels of up to 500 to 1300 mg/kg bw/day, revealed no evidence of carcinogenicity. Based on the same dataset for long-term toxicity/carcinogenicity, previous evaluations of the SCF, JECFA, TemaNord and BIBRA also concluded that there was no evidence for carcinogenicity of Brilliant Black BN.

Several other subchronic, reproductive, developmental and long-term studies did not report any other effects attributable to Brilliant Black BN. These studies revealed No-Observed-Adverse-Effect-Level (NOAEL) values that amount to 1300 mg/kg bw/day in mice, and variously, 500 or 2500 mg/kg bw/day in rats.

The SCF, JECFA and TemaNord evaluations concluded, based on mutagenicity studies available at that time, that Brilliant Black BN did not show any genotoxic activity.

Results obtained by Macioszek and Kononowicz in 2004 have indicated that Brilliant Black BN may have clastogenic and/or aneugenic and DNA-damaging properties, based on positive results obtained in a micronucleus test and a Comet assay in vitro. The Panel considers that the available genotoxicity data on Brilliant Black BN are too limited to conclusively decide on the genotoxic potential of Brilliant Black BN, or indirectly its metabolites. However in the light of negative carcinogenicity studies and negative reproductive toxicity studies, the Panel considers that additional research on the in vivo genotoxicity of Brilliant Black BN and/or in vitro genotoxicity of its metabolites is not warranted at this time.

The conversion of the parent compound by azo reduction in vivo, results in the formation of sulphonated naphthylamines that may not be formed in the in vitro genotoxicity tests. A range of sulphonated aromatic amines was shown, in general, not to be associated with genotoxicity in vitro and in vivo, in contrast to their unsulphonated analogues. Although not all the sulphonated aromatic amine metabolites that could in theory be formed by azo reduction of Brilliant Black BN were included in the study, the Panel concludes that the data reviewed are sufficient to support the conclusion that the sulphonated aromatic amines formed from Brilliant Black BN do not give reason for concern with respect to genotoxicity.

No data on the sensitivity to Brilliant Black BN are available. Recent studies performed under properly controlled conditions imply that sensitivity to food additives in patients with chronic urticaria/angioedema or asthma seems to be uncommon.

Due to the differences in ADIs derived by JECFA and SCF, the Panel has considered the basis of their respective settings. Because the report considered by SCF is a long-term study in rats fed with diets containing Brilliant Black BN, it appeared to constitute more convincing arguments for establishing an ADI than the short-term study considered by JECFA in pigs receiving bolus administration of Brilliant Black BN. The Panel concluded that the present database does not give reason to revise the ADI of 5 mg/kg bw/day based on a long-term carcinogenicity and toxicity study in rats.

The Panel concludes that at the current maximum reported levels of use of Brilliant Black BN, refined intake estimates (Tier 3) are generally below the ADI of 5 mg/kg bw/day. However in children under 10 years, the 95th percentile can be 6.9 mg/kg bw/day and thus exceeds the ADI at the upper end of the range.

The Panel further notes that the specifications of Brilliant Black BN need to be updated with respect to the percentage of material not accounted for that may represent sodium chloride and/or sodium sulphate as the principal uncoloured components.

The Panel noted that the JECFA specification for lead is < 2 mg/kg, whereas the EC specification is < 10 mg/kg.

The Panel notes that the aluminium lake of the colour could add to the daily intake of aluminium for which a Tolerable Weekly Intake (TWI) of 1 mg aluminium/kg bw/week has been established and that therefore specifications for the maximum level of aluminium in the lakes may be required.
 

Brilliant Black BN, Brilliant Black PN, Black PN, E151, CAS Registry Number 2519-30-4, tetrasodium 4-acetamido-5-hydroxy-6-[7-sulphonato-4-(4-sulphonatophenylazo)-1-naphtylazo]naphthalene-1,7-disulphonate, food colouring substance, EINECS number 219-746-5