EFSA Halves Previous ADI's for Brown HT Food Colour

EFSA’s ANS Panel published opinions on six food colours five of which are azodyes (food colours containing nitrogen) in November 2009, and is due to assess around thirty remaining colours in the next few years.

22 Apr 2010 --- As part of its ongoing re-evaluation of all food additives authorised for use in the European Union, EFSA’s expert Panel on food additives, the ANS Panel, has adopted scientific opinions on three further food colours.

For the colour Brilliant Black BN (E 151) – which can be used in a range of different foods, including soft drinks, bakery products and desserts – the Panel confirms the existing Acceptable Daily Intake (ADI) of 5 milligrams per kilogram of bodyweight established by the Scientific Committee on Food in 1984. The Panel concludes that only some children who regularly consume large amounts of foods containing the colour might exceed this level of intake.

With regard to the colour Brown HT (E 155) – which can also be used in soft drinks, bakery products and confectionery, as well as sauces, seasonings and pickles – the Panel has halved the previous ADI to 1.5 milligrams per kilogram of bodyweight (mg/kg bw). This is because adverse effects, such as slightly reduced weight gain, were noted in animals following long-term exposure to Brown HT at lower levels than those which were used to determine the ADI in previous evaluations.

Based on the maximum permitted use levels for this colour, together with food consumption data from several countries, the Panel concludes that exposure to Brown HT could be above the new ADI for adults and children who regularly consume large amounts of foods containing the colour. For example, a child weighing 15kg consuming more than 1.125 litres (around 3.4 standard-sized 330ml cans) of soft drinks containing Brown HT at the maximum reported use level every day would exceed the ADI of 1.5 mg/kg bw.

Brown HT (E 155) is a synthetic bis-azo dye authorised as a food additive in the EU and previously evaluated by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1977 and the EU Scientific Committee for Food (SCF) in 1984. In 1984 JECFA established an Acceptable Daily Intake (ADI) of 0-1.5 mg/kg bw/day, while the SCF established an ADI of 0-3 mg/kg bw/day.

Based on studies with radioactive Brown HT, the Panel concluded that Brown HT or its metabolites are absorbed to a limited extent in mice, rats and guinea pigs and are excreted predominantly in faeces (up to 90%) and urine (13-16%). Faecal extracts of mice and rats contained only small amounts of unchanged Brown HT, naphthionic acid and two unidentified metabolites. Urine contained naphthionic acid and one unidentified metabolite. These findings indicate that the azo-bonds of Brown HT are reductively cleaved by intestinal bacteria as is the case with other azo-dyes. It is unclear if the central ring structure (2,4-dihydroxy-3,5-diamino benzyl alcohol; an aromatic amine) is released. The radiolabel was distributed limitedly and mostly associated with the gastrointestinal tract and to a minor extent with the liver and kidney in both rats and male mice. Brown HT and/or its metabolites deposited only in the kidney and mesenteric lymph nodes.

The ADI of 0-1.5 mg/kg bw/day defined by JECFA was based on a NOAEL of 143 mg/kg bw/day derived from the long-term feeding study in mice. Although it appears that both JECFA and SCF have derived a NOAEL from the same study, their respective ADIs for 85% pure Brown HT have been set at 0-1.5 and 0-3 mg/kg bw/day respectively. No further details on both the SCF and JECFA evaluations are available.

Brown HT was tested for reproduction toxicity in a dietary three-generation study in rats revealing a NOAEL of 250 mg Brown HT/kg bw/day. In a developmental toxicity study in rats no teratogenic and embryotoxic effects were observed up to a dose level of 1000 mg/kg bw/day.

The Panel noted that although no new studies are available since previous evaluations, at present these old studies have been reviewed and published in scientific journals.

The Panel concluded that an ADI of 1.5 mg Brown HT/kg bw/day can be established based on the NOAEL in a long-term mouse study of 143 mg/kg bw/day and an uncertainty factor of 100 and rounding off the ADI of 1.5 mg/kg bw/day.

Finally, the Panel was not able to reach a conclusion on the safety of the colour Brown FK (E 154) due to significant limitations in the toxicological data available.

EFSA’s ANS Panel published opinions on six food colours five of which are azodyes (food colours containing nitrogen) in November 2009, and is due to assess around thirty remaining colours in the next few years. The re-evaluations of two further azodyes, Amaranth (E 123) and Litholrubine BK (E 180), are due to be finalised by June 2010.