SCIENTIFIC OPINION Scientific Opinion on the safety and efficacy of sodium bisulphate (SBS) for all animal species as preservative and silage additive, for pets and other non food-producing animals (non-food fur animals) as acidity regulator and for pets as flavouring 1 EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) 2,3 ABSTRACT European Food Safety Authority (EFSA), Parma, Italy The additive (SBS) consists of sodium bisulphate without carrier materials. The applicants are seeking authorisation for SBS as a silage additive and for use as feed preservative for all animal species, as acidity regulator for pets and other non food-producing animals and as flavouring for pets. The FEEDAP Panel concluded that (i) there is no convincing evidence for the safety of SBS as preservative in all animal species at the recommended maximum concentration of 1 % in complete feed, (ii) the use of SBS in pets and other non food-producing animals is safe up to a concentration of 0.5 % this maximum safe concentration of SBS cannot be applied to all animal species because of the lack of data in food-producing animals, and (iii) 0.8 % SBS added to fresh ensiling forages is safe for all animal species, based on data from a study with dairy cows. The use of SBS in animal nutrition is safe for the consumer up to the highest recommended level in complete feed. Sodium bisulphate is irritant to skin, eye and the respiratory tract and should be considered as a potential skin sensitiser. The use of SBS in feed is not expected to pose an additional risk for the environment. SBS is considered efficacious as preservative for all animal species, as acidity regulator in feed for pets and other non foodproducing animals and as flavouring substance for pets, based on the fact that SBS is authorised for the same purpose in food and on the studies provided. The FEEDAP Panel concluded that SBS is not efficacious as silage additive at the concentrations tested. The FEEDAP Panel recommended setting a maximum content of 0.5 % for SBS if authorised as acidity regulator and flavouring substance for pets and other non food-producing animals. European Food Safety Authority, 2011 KEY WORDS Sodium bisulphate, technological additive, preservative, acidity regulator, flavouring, silage additive 1 On request from European Commission, Question No EFSA-Q-2009-00868, adopted on 13 October 2011. 2 Panel members: Gabriele Aquilina, Georges Bories, Paul Brantom, Andrew Chesson, Pier Sandro Cocconcelli, Joop de Knecht, Noël Albert Dierick, Mikolaj Antoni Gralak, Jürgen Gropp, Ingrid Halle, Reinhard Kroker, Lubomir Leng, Sven Lindgren, Anne-Katrine Lundebye Haldorsen, Alberto Mantovani, Miklós Mézes, Derek Renshaw and Maria Saarela. Correspondence: FEEDAP@efsa.europa.eu 3 Acknowledgement: The Panel wishes to thank the members of the Working Group on Technological additives, including Bogdan Debski and Carlo Nebbia, for the preparatory work on this scientific opinion. Suggested citation: EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP); Scientific Opinion on the safety and efficacy of sodium bisulphate (SBS) for all animal species as preservative and silage additive, for pets and other non food-producing animals (non-food fur animals) as acidity regulator and for pets as flavouring. EFSA Journal 2011;9(11):2415. [16 pp.]. doi:10.2903/j.efsa.2011.2415. Available online: www.efsa.europa.eu/efsajournal European Food Safety Authority, 2011
SUMMARY Following a request from the European Commission, the Panel on Additives and Products used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of sodium bisulphate (SBS) for all animal species as preservative and silage additive, for pets and other non food-producing animals as acidity regulator and for pets as flavouring substance. The FEEDAP Panel concluded that (i) there is no convincing evidence for the safety of SBS as preservative in all animal species at the recommended maximum concentration of 1 % in complete feed, (ii) the use of SBS in pets and other non food-producing animals is safe up to a concentration of 0.5 % this maximum safe concentration of SBS cannot be applied to all animal species because of the lack of data in food-producing animals, and (iii) 0.8 % SBS added to fresh ensiling forages is safe for all animal species, based on data from a study with dairy cows. The use of SBS in animal nutrition is safe for the consumer up to the highest recommended level in complete feed. Sodium bisulphate is irritant to skin, eye and the respiratory tract, and should be considered a potential skin sensitiser. The use of SBS in feed is not expected to pose an additional risk for the environment compared to the use of sodium sulphate as feed material and sulphates as fertilisers. SBS is considered efficacious as preservative for all animal species, as acidity regulator in feed for pets and other non food-producing animals and as flavouring substance for pets, based on the fact that SBS is authorised for the same purpose in food and on the studies provided. The FEEDAP Panel concluded that SBS is not efficacious as silage additive at the concentrations tested (0.4 and 0.8 %). The FEEDAP Panel recommended setting a maximum content of 0.5 % for SBS if authorised as acidity regulator and flavouring substance for pets and other non food-producing animals. 2
TABLE OF CONTENTS Abstract... 1 Summary... 2 Table of contents... 3 Background... 4 Terms of reference... 4 Assessment... 7 1. Introduction... 7 2. Characterisation... 7 2.1. Characterisation of the product... 7 2.2. Stability and homogeneity... 8 2.3. Conditions of use... 8 2.4. Evaluation of the analytical methods by the European Union Reference Laboratory (EURL) 8 3. Safety... 8 3.1. Safety for the target species... 8 3.2. Safety for the consumer... 10 3.3. Safety for the user... 10 3.4. Safety for the environment... 11 4. Efficacy... 11 4.1. Silage additive... 11 5. Post-market monitoring... 13 Conclusions and recommendations... 13 Documentation provided to EFSA... 14 References... 14 Appendix... 16 3
BACKGROUND Regulation (EC) No 1831/2003 4 establishes the rules governing the Community authorisation of additives for use in animal nutrition. In particular, Article 4(1) of that Regulation lays down that any person seeking authorisation for a feed additive or for a new use of a feed additive shall submit an application in accordance with Article 7 ; in addition, Article 10(2)/(7) of that Regulation specifies that for existing products within the meaning of Article 10(1), an application shall be submitted in accordance with Article 7, within a maximum of seven years after the entry into force of this Regulation. The European Commission received a request from the companies Jones-Hamilton Co. and Grillo- Werke AG 5 for authorisation of the product SBS (sodium bisulphate), to be used as a feed additive for all animal species as preservative and silage additive; for pets and other non food-producing animals (non-food fur animals) as acidity regulator and for pets as flavouring under the conditions mentioned in Table 1. According to Article 7(1) of Regulation (EC) No 1831/2003, the Commission forwarded the application to the European Food Safety Authority (EFSA) as an application under Article 4(1) (authorisation of a feed additive or new use of a feed additive) and under Article 10(2)/(7) (reevaluation of an authorised feed additive). EFSA received directly from the applicant the technical dossier in support of this application. 6 According to Article 8 of that Regulation, EFSA, after verifying the particulars and documents submitted by the applicant, shall undertake an assessment in order to determine whether the feed additive complies with the conditions laid down in Article 5. The particulars and documents in support of the application were considered valid by EFSA as of 5 February 2010. The additive SBS is a preparation of sodium bisulphate produced by chemical synthesis. This product has not been previously authorised in the Community as preservative, acidity regulator and flavouring. This product was included in the European Union Register of Feed Additives following the provisions of Article 10(1) of Regulation (EC) No 1831/2003 as silage additive. TERMS OF REFERENCE According to Article 8 of Regulation (EC) No 1831/2003, EFSA shall determine whether the feed additive complies with the conditions laid down in Article 5. EFSA shall deliver an opinion on the safety for the target animal(s), consumer, user and the environment and the efficacy of the product SBS (sodium bisulphate), when used under the conditions described in Table 1. 4 5 6 OJ L 268, 18.10.2003, p. 29. Jones-Hamilton Co., 30354 Tracy Road, Walbridge, OH 43465-9792, USA; Grillo-Werke AG, Weseler Straße 1,47169 Duisburg, Germay. EFSA Dossier reference: FAD-2009-0049. 4
Table 1: Description and conditions of use of the additive as proposed by the applicant Additive Registration number/ec No/No (if appropriate) Category(-ies) of additive Functional group(s) of additive Sodium bisulphate E 514ii, 1k Technological/Sensory Preservative, silage additive, acidity regulator, flavoring compound Composition, description Preparation of E 514ii sodium bisulphate (minimum 95.2%) as dry (anhydrous), nondusting (>100 μm diameter spheres) granular crystals Trade name (if appropriate) Name of the holder of authorisation (if appropriate) Description Chemical Purity criteria formula (if appropriate) NaHSO4 Complies with EU law on undesirable substances SBS Jones_Hamilton Co. & Grillo-Werke AG Method of analysis (if appropriate) CEN methods for sodium & sulphates Species or category of animal All species (preservative & silage addtive) Maximum Age - Conditions of use Minimum content Maximum content Withdrawal period mg/kg of complete feedingstuffs (if appropriate) Quantum satis (add as much is needed) Quantum satis (add as much is needed) Not appropriate Pets & non-food fur animals (acidity regulator) - Quantum satis (add as much is needed) Quantum satis (add as much is needed) Not appropriate Pets (flavouring compound) - Quantum satis (add as much is needed) Quantum satis (add as much is needed) Not appropriate Other provisions and additional requirements for the labelling Specific conditions or restrictions None for use (if appropriate) Specific conditions or restrictions For user safety breathing protection, safety glassses & rubber for handling (if appropriate) gloves. Post-market monitoring Not required. (if appropriate) Specific conditions for use in complementary feedingstuffs Sufficient to supply recommended dosage in final feeds. (if appropriate) 5
Maximum Residue Limit (MRL) (if appropriate) Species or category of Target tissue(s) or Maximum content in Marker residue animal food products tissues - - - - 6
ASSESSMENT This opinion is based on data provided by two companies involved in the production of sodium bisulphate (SBS). The application concerns the active substance and the composition of an additive formulation is not the subject of the application. The FEEDAP Panel has sought to use the data provided together with data from other sources to deliver an opinion and to produce recommendations for the authorisation, which would secure the safety of future uses of SBS as feed additive. 1. Introduction The applicants are seeking authorisation for SBS as silage additive for all animal species and for use as feed preservative for all animal species, as acidity regulator for pets and other non food-producing animals and as flavouring substance for pets. Sodium bisulphate is approved under the heading sodium hydrogen sulphate (E 514ii) as a food additive (Directive No 95/2/EC 7 ), without restriction for use as preservative, acid, acidity regulator and flavour enhancer. SBS is also authorised as feed and food additive in other countries (e.g. in the USA as preservative, for ph reduction, palatability enhancement and urinary acidification in cats). The substance is also used as disinfectant and ph regulator for swimming pools, 8 acid-type cleaner in cleaning agents 9 and as ammonia regulator to reduce ammonia emission from farm animal manure. 10 The additive has been assessed by the Joint FAO/WHO Expert Committee on Food Additives. The JECFA allocated an ADI as not specified in line with the principles established for ionisable salts when used in the applications specified and in accordance with Good Manufacturing Practice (JECFA, 2009). 2. Characterisation 2.1. Characterisation of the product Sodium bisulphate (sodium hydrogen sulphate; acid sodium sulphate; nitre cake), CAS No 7681-38-1, molecular weight 120.07, molecular formula NaHSO 4, contains 19.15 % sodium and 80.01 % SO 4. The density is 2.74 kg/dm 3. The additive is odourless to slightly fresh/pungent and consists of spherical white beads with a mean particle size of 750 µm and 0.06 % particles smaller than 150 µm. The product consists of sodium bisulphate (95.2 % by specification) without carrier materials. Product consistency is confirmed by analyses of nine batches (five 11 and four 12 from the two producers) showing a mean value of 96.6 % sodium bisulphate, the minimum value being 95.7 %. The analysis of five batches from one applicant indicated also the presence of anhydrous sodium sulphate in a range of 1.6 3.2 %. 13 The specification of the applicant for lead, selenium, mercury and arsenic is < 2 mg/kg, < 0.5 mg/kg, < 3 mg/kg and < 1 mg/kg, respectively. These specifications were met in all eight batches analysed. 14 7 OJ No L 61, 18. 3. 1995, p. 1. 8 Technical dossier/section II/ref. Pool_water_balance_2009. 9 Technical dossier/section II/ref. Home_cleaners_2003.pdf. 10 Technical dossier/section II/ref. RCVS_Literature_Review.pdf. 11 Technical dossier/section II/Annex_II_1_3. 12 Technical dossier/section II/Annex_II_1_4. 13 Technical dossier/section II/Annex_II_1_3. 14 Technical dossier/section II/Annex_II_1_4. 7
The analytical data comply with the requirements set by Commission Directive 2008/84/EC 15 for heavy metals and arsenic. The applicant provided a full description of the production process, where salt (NaCl) and sulphuric acid (H 2 SO 4 ) are used as starting materials for the chemical synthesis. 2.2. Stability and homogeneity A study on three batches of SBS showed a shelf life of three years when stored in polyethylene bags at ambient temperature (20 25 C). 16 Stability of technological additives in feed can generally be demonstrated by maintenance of the effect. The stability of the additive (three batches) at a level of 0.5 % in pelleted feed was demonstrated as analytical follow-up of its activity (reduction of ph). After three months of storage (20 25 C; 50 60 RH), no differences to the initially reduced ph values were observed. 17 Since the flavouring property is based on the acid taste of the additive, those findings are considered also representative for SBS as flavouring additive. The homogenous distribution of the additive was demonstrated in the same pelleted feed used for the stability studies (three batches, ten subsamples each). The coefficient of variation was 1 % for the ph value and 5 % for the sulphur content. 18 For the use of SBS as silage additive, stability and homogeneity studies are not required. 2.3. Conditions of use The additive is intended to be used in all animal species/categories (without limitations for age) and without withdrawal period as preservative and silage additive, in pets and non-food fur animals as acidity regulator and in pets as flavouring substance. For all uses, no minimum and maximum doses were specified. The recommended supplementation level for SBS as technological additive, functional group preservative is 0.5 to 3 %, silage additive 0.1 to 0.8 %, acidity regulator for pets and non-food fur animals 0.5 to 2.5 % and as flavouring substance for pets 0.15 to 1 %. These data refer to feed materials. The highest inclusion level recommended for complete feed is 1 %. 2.4. Evaluation of the analytical methods by the European Union Reference Laboratory (EURL) EFSA has verified the EURL report as it relates to the methods used for the control of sodium bisulphate in animal feed. The Executive Summary of the EURL report can be found in the Appendix. 3. Safety 3.1. Safety for the target species Sodium bisulphate is an approved food additive in the European Union. If the use level of the feed additive is less than or similar to that in food, tolerance studies to assess the safety for the target species are not required and the safety for the target species could be assessed based on the available in vivo toxicological data. Converting human intake data to metabolic body weight and comparing this with animal intake on the same basis does not appear necessary because the concentrations used in food are similar to those in feed. This may result in a final concentration of SBS in complete pet diets of 0.15 %. Consequently, this approach cannot be used for higher concentrations as applied for all animal species. 15 OJ L 253/1, 20.9.2008, p. 1. 16 Technical dossier/supplementary Information April 2011/Annex_II_4. 17 Technical dossier/supplementary Information April 2011/Annex_II_4. 18 Technical dossier/supplementary Information April 2011/Annex_II_4. 8
Three studies with SBS on chickens for fattening were submitted as tolerance studies. In the first experiment, a total of 120 birds were fed a pelleted maize soybean type diet containing 0.75 % SBS for 21 days. 19 Groups of four replicates with five birds each received a shock dose of SBS equivalent to 0.75, 1.25, 2.50, 5.00, 6.25 and 12.50 % of the diet by gavage on days 10 and 18. At the end of the experiment, all birds were euthanised and necropsied. The average body weight was not significantly different between the treatments on days 10, 13, 18 and 21, nor was feed to gain ratio on days 10, 13 and 18. Significant differences in feed to gain ration on day 21 were not treatment-related. Mortality/culls among the treatments ranged from 10 to 25 % but were not treatment-related. Several birds were removed early in the study due to dehydration. In trial 2, a total of 828 chickens for fattening was fed a maize soybean type mash diet containing 0, 0.25 and 0.75 % SBS for 49 days. 20 The group size was six replicates per sex with 23 birds each. Both SBS doses significantly increased final body weight; feed to gain ratio was significantly improved by 0.75 % SBS. Mortality was not reported. Gut morphology, blood ph, pco 2 and HCO 3 were determined on days 21, 35 and 49. There was no evidence of either positive or negative effects on these parameters. In trial 3, a total of 800 chickens for fattening received a maize soybean type diet (crumbles for the first two weeks, followed by pellets) containing 0, 0.25, 0.50 and 0.75 % SBS for 49 days. 21 The group size was four replicates per sex with 25 birds each. Final body weight was not influenced by the treatment. Final feed to gain ratio was significantly improved by the two higher SBS concentrations. Total mortality was high, mainly by heat stress during summer time, ranging between 15 and 23 % for the males and between 7 and 11 % for the females, but not dose-dependent. Two studies with weaned piglets were provided. In the first study, 200 piglets of 21 days of age and a body weight of 6 kg were used, 22 in the second study 240 piglets of the same age and a body weight of 5-6 kg. 23 All piglets were pre-fed for seven days, then the experimental diets (pelleted, maize soybean type) containing 0, 0.2, 0.4 and 0.8 % SBS were fed for 43 days. All diets contained an antibiotic (not specified) and ZnO (0.28 % for the first four weeks). Final body weight and feed to gain ratio were not significantly influenced by the treatments. In a study with pigs for fattening, 80 pigs (initial body weight: 37 kg) were fed for 99 days corn soybean type pelleted diets, supplemented with an antibiotic, without SBS and with SBS (0.3 % for the first seven weeks, followed by 0.5 % for four weeks and 1.0 % for the final three weeks). 24 The group size was two replicates (rooms) with 20 pigs each. No significant differences in final body weight and feed to gain ratio were observed. In two other studies, SBS was used as an acidity regulator in minks. In a first study, 25 129 minks of four weeks of age received wet diets with 1 % SBS or 1 % phosphoric acid (75 %) for 82 days. The group size for the SBS treatment was 41 females and 25 males, for the phosphoric acid treatment 39 females and 24 males. SBS reduced weight gain, although not significantly, from 121 g to 100 g in females and from 33 g to 10 g in males, compared to the phosphoric acid control group. Faecal dry matter (n = 16/treatment) was significantly reduced by the SBS treatment (30.7 vs. 25.4 %). In the second study (Clausen et al., 2007), groups of 47 male kits (initial body weight 849 g) received wet diets containing no acidity regulator, 0.5 % SBS and 0.2 % ammonium chloride for five months. SBS lowered the ph value of feed consistently (three measurements) from 5.8 of the unsupplemented control feed to 5.3. The average final body weight was 2607 g without differences between the groups. 19 Technical dossier/supplementary Information September 2011/Annex_III_1_3. 20 Technical dossier/supplementary Information September 2011/Annex_III_1_4. 21 Technical dossier/supplementary Information September 2011/Annex_III_1_5. 22 Technical dossier/supplementary Information September 2011/Annex_III_1_6. 23 Technical dossier/supplementary Information September 2011/Annex_III_1_6. 24 Technical dossier/supplementary Information September 2011/Annex_III_1_6. 25 Technical dossier/section IV/Annex IV_3_1 9
Another publication was provided to demonstrate the safety of SBS when used as silage additive in dairy cows (Naumenko et al., 1995). Clover-timothy silage was made with SBS added at 0 or 8 kg/tonne fresh, green matter. For 103 days, 40 cows were fed on either silage. The SBS-treated silage contained more protein, fat and ash but less fibre than did the traditionally prepared silage. However, the test and control silages appeared isocaloric. Milk yield of cows during peak-, mid- and latelactation was 13.6 %, 4.8 % and 14.8 % higher, respectively, for cows on the SBS-treated silage. Blood biochemistry indicated no adverse effects due to the SBS-treated silage. Short-term studies (e.g. palatability studies in cats with two-day administration) could not be considered. None of the studies submitted comply with the principles established for tolerance trials since no overdose was continuously administered and none used the highest dose recommended (1 % in complete diets). The high mortality observed in chicken trial 3, the simultaneous use of antibiotics in the piglet/pig studies and the use of overdoses for only two days of a 21-day experiment (chicken trial 1) preclude conclusions on the tolerance of animals to the recommended dose of 1 % SBS. The FEEDAP Panel concludes that there is no convincing evidence for the safety of SBS used as preservative in all animal species at the recommended concentration of 1 % in complete feed. A different situation may arise from the use of SBS as flavouring substance in pets and as acidity regulator in pets and other non food-producing animals, since the use doses do probably not exceed 0.15 % and 0.25 %, respectively, in complete diets. The mink studies showed that 1 % SBS in mink diets resulted in adverse effects, but 0.5 % was tolerated. The FEEDAP Panel concludes that the use of SBS in pets and other non food-producing animals is safe up to a concentration of 0.5 %. Although the dairy cow study was not performed according to the principles established for tolerance trials with silage additives (use of the same feed), it allows the conclusion that 0.8 % SBS added to fresh ensiling forages is safe for dairy cows. Considering that silage contributes under European feeding conditions in high yielding cows to about half of the daily ration, the conclusion is approximately in line with the safe use of SBS in pets and other non food-producing animals. The conclusion on the safety of 0.8 % SBS as silage additive can be extended to all animal species. 3.2. Safety for the consumer SBS will dissociate in water solutions and consequently in the intestine, where the ions are absorbed separately; they enter the respective metabolic pathways and body pools. The sodium concentration in body fluids, particularly the plasma, is strongly controlled by homeostatic mechanisms, any surplus will be excreted mainly via the kidneys (and faeces in case of ruminants). The (bi)sulphate, also of endogenous origin, will mainly be excreted via the kidneys (the amount exceeding glomerular reabsorption capacity); it is a physiological ion in urine associated with sodium, potassium and ammonium. No increase in the concentration of sodium and sulphate ions in tissues and products is expected. Since the consumer is not exposed to SBS from tissue/products of animals treated with the additive, its use in animal nutrition is safe for the consumer up to the highest recommended level in complete feed. 3.3. Safety for the user Sodium bisulphate induced mild to severe skin erythema and necrosis in a Draize test in rabbits, 26 but it was found non irritant to skin in a second Draize test in rabbits. 27 From general manufacturing and use experience, sodium bisulphate is known to be irritant to eyes, as reported by the applicant. 26 Technical dossier/section III/Annex_III_2. 27 Technical dossier/section III/Annex_III_3_1_2. 10
Inhalatory exposure would be negligible considering the particle size distribution suggesting low dusting potential of the additive. No information on the sensitisation potential of the additive was provided. Therefore, it should be considered as a potential skin sensitiser. The FEEDAP Panel concludes that sodium bisulphate is irritant to skin, eye and the respiratory tract. 3.4. Safety for the environment Sodium bisulphate will dissociate in the intestine of the target organisms where the ions will be absorbed separately. Sodium and sulphate are physiological ions which will be excreted more or less quantitatively via the urine (sodium also in faeces of ruminants). The use of SBS in feed is not expected to pose an additional risk for the environment compared to the use of sodium sulphate as feed material and sulphates as fertilisers. 4. Efficacy Sodium bisulphate is added to food as preservative, acidity regulator and flavour enhancer and would be expected to exert corresponding effects when used in animal nutrition. Consequently, no studies are required to demonstrate the efficacy as preservative, acidity regulator or flavour in animal nutrition. Some data specific for the use of SBS in feed were provided. The study submitted to demonstrate stability indicates a decrease in ph in pelleted feed from 6.0 to 5.1 at a concentration of 0.25 % SBS. 28 Two standard two-bowl palatability studies performed on cats were provided to support the effect of SBS as flavour enhancer for pets. In the first study, 20 individually housed cats were offered simultaneously a test diet with 1 % of SBS and a control diet for two days. 29 At the time of feeding, first approach and first choice (first consumption) preferences were recorded. The remaining food was weighed back after 20 hours. Feed consumption data was statistically analysed with a student's t-test for paired data, feed consumption distribution was analysed with a Wilcoxon signed rank test for paired data and first approach and first choice were analysed with Chi Square tests. The diet with 1 % of SBS was consumed in a higher rate than the control diet (1790 g vs. 948 g; P = 0.05). No differences were noted in the first approach and first choice data. In the second study, 20 individually housed cats were offered a diet with 0.9 % of SBS and a control diet with 0.9 % of phosphoric acid, for two days. 30 First consumption preferences and total consumption were recorded. During the two days of the trial, the cats consumed higher amounts of the diet with SBS (2914 g vs. 2045 g) and showed a higher preference for the same diet (first choice: 27 vs. 12). However, no statistical analysis was performed. The FEEDAP Panel considers SBS as an effective flavouring agent for pets. 4.1. Silage additive Two sets of experiments, one with five forages and one with two forages, were provided. In the first set of experiments, the five studies used 30 L mini silos and lasted 90 days. 31 The different batches of the forages were treated with 4 or 8 g SBS/kg fresh forage. The silos were stored at ambient temperature (18 25 C). The five studies involved a range of forages of differing botanical origin and water-soluble carbohydrate (WSC) content primarily selected to show a wide range of dry matter content (Table 2). 28 Technical dossier/supplementary Information April 2011/Annex_II_4. 29 Technical dossier/section IV/Annex_IV_2_2. 30 Technical dossier/supplementay information April 2011/Annex_IV_2_5. 31 Technical dossier/supplementary Information April 2011/Annex IV_2_7. 11
The samples represented material easy to ensile (experiments 1 and 2) and moderately difficult to ensile (experiments 3, 4 and 5) as defined in Regulation (EC) No 429/2008 (Table 2). Table 2: Characteristics of the forage samples used in the ensiling experiments Dry matter content (% fresh material) Study Test material First cut, wilted red clover/perennial rye 1 grass Second-cut, wilted red 2 clover/perennial rye grass First cut, unwilted red clover/perennial 3 rye grass First cut, unwilted old permanent 4 pasture 5 Second-cut unwilted red clover/perennial rye grass a WSC: water-soluble carbohydrate. * Analysis of the forage performed after treatment but before ensiling, average data. b WSC content in treatment and control forages before ensiling were statistically different (P < 0.05). WSC content a (% fresh material) 41.1 5.80 70.5* 7.78 21.6 2.57 23.1* 1.71* b 19.1* 1.67* The information on ph data was statistically evaluated using the one-sided Wilcoxon Kruskal-Wallis non-parametric test (Table 3). 32 Table 3: Summary of the analysis of ensiled material recovered at the end of the experiments and the aerobic stability after opening of the silo (90 days) Study Dose g/kg fresh matter ph DM 1 (%) Lactic acid (% DM) Acetic acid (% DM) Ethanol (% DM) Aerobic stability (hours) 0 4.4 36.3 11.72 1.76 4.96 nd 2 1 4 4.3 34.7 9.99 1.68 6.74 nd 0 5.8 59.0 0.95 0.16 3.45 nd 2 8 5.6* 64.4 0.50 0.08 2.30 nd 0 3.9 18.7 17.02 2.09 11.43 99 3 4 3.8* 19.8 13.83 1.48 8.67 114 0 4.1 21.4 7.38 2.43 3.92 122 4 8 3.8* 21.2 6.43 2.21 4.61 110 0 3.9 17.7 9.20 2.79 2.63 107 5 8 3.7* 17.8 9.10 2.21 3.33 104 1 Dry matter. 2 nd: a difference in temperature of 3 C above the ambient temperature not achieved for a sustained period of time. * P < 0.05 compared to control. In the second set of experiments, the two studies used 5 L mini silos and lasted 100 days. 33 The different batches of the forages were treated with 4 or 8 g SBS/kg fresh forage. The silos were stored at ambient temperature (18 25 C). The samples represented material easy to ensile (experiments 6 and 7) as defined in Regulation (EC) No 429/2008 (Table 4). In both experiments, the forages were not analysed after harvesting but at day 0, after treatment with SBS, before ensiling. 32 Technical dossier/supplementary Information September 2011/Annex IV_2_7_1. 33 Technical dossier/supplementary Information April 2011/Annex IV_2_6. 12
Table 4: Characteristics of the forage samples used in the ensiling experiments Study Test material WSC content a Dry matter content (% fresh material) Sodium bisulphate Control Sodium bisulphate Control 6 First cut perennial rye grass 17.4 17.1 5.51 6.06 7 Alfalfa 42.62 43.05 4.53 3.05 a WSC: water-soluble carbohydrate. The results were statistically evaluated by one-sided Wilcoxon Kruskal-Wallis non-parametric test (Table 5). 34 Table 5: Summary of the analysis of ensiled material recovered at the end of the experiments and the aerobic stability after opening of the silo (100 days) Study Dose (g/kg fresh matter) ph DM 1 recovery at day 107 (%) 93.9 91.4 96.4 98.2 Lactic acid (% DM) Acetic acid (% DM) Ethanol (% DM) NH3-N (% of total N) 0 3,82 12.04 2.84 0.92 11.8 6 4 3,68* 10.51 2.07 2.27 9.9 0 5.81 4.08 2.90 0.08 14.6 7 8 5.44* 3.94 2.18 0.09 11.8 1 Dry matter. 2 nm.: not measured. 3 nd: a difference in temperature of 3 C above the ambient temperature not achieved for a sustained period of time. * P < 0.05 compared to control. Aerobic stability (hours) The results of the studies showed that the only significant effect consisted in a decrease of the ph value of the silages from easy and moderately difficult to ensile forages (six out of seven studies) at the dose of 4 or 8 g/kg fresh material. Lactic acid was decreased in all studies. An effect on increased aerobic stability could not be shown. The FEEDAP Panel concludes that SBS is not efficacious as silage additive at the concentrations tested. 5. Post-market monitoring The FEEDAP Panel considers that there is no need for specific requirements for a post-market monitoring plan other than those established in the Feed Hygiene Regulation 35 and Good Manufacturing Practice. CONCLUSIONS AND RECOMMENDATIONS nm 2 nm nd 3 nd CONCLUSIONS The FEEDAP Panel concludes that - there is no convincing evidence for the safety of SBS as preservative in all animal species at the recommended maximum concentration of 1 % in complete feed, - the use of SBS in pets and other non food-producing animals is safe up to a concentration of 0.5 %. This maximum safe concentration of SBS cannot be applied to all animal species because of the lack of data in food-producing animals, 34 Technical dossier/supplementary Information September 2011/Annex IV_2_6_1. 35 OJ L 35, 8.2.2005, p. 1. 13
- 0.8 % SBS added to fresh ensiling forages is safe for dairy cows. This conclusion can be extended to all animal species. The use of SBS in animal nutrition is safe for the consumer up to the highest recommended level in complete feed. Sodium bisulphate is irritant to skin, eye and the respiratory tract, and should be considered a potential skin sensitiser. The use of SBS in feed is not expected to pose an additional risk for the environment compared to the use of sodium sulphate as feed material and sulphates as fertilisers. SBS is considered efficacious as preservative for all animal species, as acidity regulator in feed for pets and other non-food producing animals and as flavouring substance for pets, based on the fact that SBS is authorised for the same uses in food and on the studies provided. The FEEDAP Panel concludes that SBS is not efficacious as silage additive at the concentrations tested (0.4 and 0.8 %). RECOMMENDATIONS The FEEDAP Panel recommends setting a maximum content of 0.5 % for SBS if authorised as acidity regulator and flavouring substance for pets and other non food-producing animals. The specification for mercury should be adapted to the provisions of Commission Directive 2008/84/EC. 36 DOCUMENTATION PROVIDED TO EFSA 1. Sodium bisulphate (SBS) for all species as preservative and silage additive; for pets and other non food-producing animals (non-food fur animals) as acidity regulator and for pets as flavouring. December 2009. Submitted by Jones-Hamilton Co. and Grillo-Werke AG. 2. Sodium bisulphate (SBS) for all species as preservative and silage additive; for pets and other non food-producing animals (non-food fur animals) as acidity regulator and for pets as flavouring. Supplementary information. April 2011. Submitted by Jones-Hamilton Co. and Grillo-Werke AG. 3. Sodium bisulphate (SBS) for all species as preservative and silage additive; for pets and other non food-producing animals (non-food fur animals) as acidity regulator and for pets as flavouring. Supplementary information. September 2011. Submitted by Jones-Hamilton Co. and Grillo-Werke AG. 4. Evaluation report of the European Union Reference Laboratory for Feed Additives on the methods(s) of analysis for sodium bisulphate. 5. Comments from Member States received through the ScienceNet. REFERENCES Clausen TN, Sandbøl P and Hejlesen C, 2007. Sodium-bisulfate and ammonium chloride for mink in the growing period. NJF Seminar No. 403, Kolding, Denmark. JECFA (Joint FAO/WHO Expert Committee On Food Additives), 2009, online. Seventy-first meeting. Geneva, 16-24 June 2009. Available from: http://www.who.int/foodsafety/chem/jecfa/summaries/summary71.pdf 36 OJ L 253/1, 20.9.2008, p. 1. 14
Naumenko PA, Tyutyunnik MV, Marinov KA and Fridberg RV, 1995. Nutritive and productive action of silage prepared with a chemical preservative. Zootekhniya, 11, 17-18. 15
APPENDIX Executive Summary of the Evaluation Report of the Community Reference Laboratory for Feed Additives on the Method(s) of Analysis for sodium bisulphate 37 In the current application authorisation is sought for Sodium Bisulphate under the category technological additives and sensory additives, functional group 1(a) preservatives (all species), 1(j) acidity regulators (pet & non-food fur animals), 1(k) silage additive (all species), 2(b) flavouring compounds(pets:dogs & cats), according to Annex I of Regulation (EC) No 1831/2003. The active agent is sodium bisulphate of technical grade with a minimum purity of 95.2%. It is intended to be marketed as a dry (anhydrous), non-dusting (>100 μm diameter spheres) granular crystals to be incorporated into premixtures and/or complete feedingstuff at quantum satis concentration. For the determination of sodium bisulphate in feed additive the applicant proposes the Food Chemicals Codex IV (FCC IV) monograph. The method is based on a titrimetric assay for the determination of sodium bisulphate for industrial use. The CRL recommends this FCC IV monograph method for official controls for the determination of sodium bisulphate in feed additives. The unambiguous determination of the content of exogenous sodium bisulfate added to premixtures or feedingstuffs is not achievable by analysis. The Applicant did not provide any experimental method or data on this matter. Furthermore, no international standard methods of analysis could be identified. Therefore the CRL cannot evaluate nor recommend any method for official control to determine sodium bisulfate in premixtures or feedingstuffs. Further testing or validation is not considered necessary. 37 The full report is available on the EURL website: http://irmm.jrc.ec.europa.eu/sitecollectiondocuments/finrep-fad- 2009-0049.pdf 16