Chemicals Rather than Bacteria? – Neither is Permitted in the EU
Part 2: Plant powder and nutritional supplements
Ellen Scherbaum, Dr. Christiane Lerch, Leonie Moser, Eric Eichhorn, Dr. Michelangelo Anastassiades
» Part 1: Residues of Fumigations with Ethylene Oxide in Sesame Seeds
» Part 3: Instant Noodles – Asian also fumigated with ethylene oxide!
In August 2020 high amounts of ethylene oxide in sesame seeds from India were reported in Belgium and communicated in September via the European Rapid Alert System for Food and Feed (RASFF). The EU Commission reacted quickly and decisively: in the meantime sesame seeds from India may now only be imported into the EU when accompanied by an appropriate negative analysis certificate [1]; ethylene oxide in the seeds are now rarely conspicuous.
As official food controllers, however, we are still working on the case. We have continued and expanded our investigations to include other types of food samples, made possible by our newly developed analytical methods. Nutritional supplements, for example, have made our hit list, yielding a surprisingly high number of findings.
What is ethylene oxide?
Ethylene oxide is a colorless, highly flammable gas with a sweet smell. It is mainly used as an intermediary product in the synthesis of other chemicals. A tiny fraction (~0.05 % of world production) is used to fumigate and disinfect medical instruments or to combat mold and bacteria in foods, such as spices, nuts and oil seeds.
How is the application of ethylene oxide regulated?
For toxicological reasons, the application of ethylene oxide as a food fumigant was already banned in Germany in 1981. In 1991 its use as a pesticide was fully banned in the entire EU, due to its categorization as a carcinogen and mutagen. It is also explicitly banned in the EU for the sterilization of food additives (see Info Box) [5].
In 2008, the currently valid residue definition was established as the sum of ethylene oxide and 2-chloroethanol, expressed as ethylene oxide [2]. The maximum authorized levels were set at the agreed analytical limit of quantification.
The use of ethylene oxide is still permissible in third countries such as India, but also in the USA and Canada. The motto here seems to be, “chemicals are better than bacteria”. At the end of 2019 in Canada an MRL of 7 mg/kg for ethylene oxide and of 940 mg/kg (!) for 2-chloroethanol in sesame seeds were recommended and then legalized on 10 January 2020 [3, 4].
Info Box
Ethylene Oxide in Food Additives Legislation
The EU regulates, among others, the use of additives via Regulation (EC) No. 1333/2008. It also specifies here that only additives adhering to the specifications in Regulation (EU) No. 231/2012 may be applied (Appendix II, Part A, No. 21.1 of Regulation (EC) No. 1333/2008). As stated in the Appendix to Regulation (EU) No. 231/2012, ethylene oxide may not be used for the sterilization of additives. According to Article 5 of Regulation (EC) No. 1333/2008, foods containing additives that do not adhere to the specifications stipulated by this Regulation may not be sold [6].
How is ethylene oxide determined in foods?
Ethylene oxide is an extremely volatile and reactive compound. In treated foods it is generally present in such small amounts that it is no longer detectable as such. The most important reaction product of ethylene oxide in food is 2-chloroethanol. Legislation therefore foresees residue limits for the summed-up residue of ethylene oxide and 2-chloroethanol, calculated as ethylene oxide. In 2020, CVUA Stuttgart developed an analytical procedure that can individually determine the presence of ethylene oxide and 2-chloroethanol as separate substances [7]. We successfully integrated both substances into established, widely used multi-methods (QuEChERS, QuOil) [8], thereby enabling the routine analysis of ethylene oxide and its reaction product on a large scale.
How are the detected amounts judged in terms of their toxicity?
In its official opinion paper, the Federal Institute of Risk Assessment (BfR) specifies an “intake amount of minimal concern” for ethylene oxide, amounting to 0.037 µg per kg body weight (see Info Box). No toxicological threshold could be elaborated for 2-chloroethanol (2-CE) due to lack of sufficient data. From BfR’s point of view, the risk assessment of the suspected mutagen 2-CE should be carried out based on the toxicological threshold derived for its parent compound ethylene oxide. If the “intake amount of minimal concern” is exceeded, the food in question is classified as unsafe; an exceedance of two or more times the above-mentioned amount will result in the food product being judged a health hazard. In both cases, the affected food product will have to be removed from the market as a protective measure for consumer health.
Info Box
Toxicological Assessment of Ethylene Oxide and 2-Chloroethanol
Ethylene oxide is classified by the European Chemicals Agency (ECHA Classification [10]) as a Category 1B carcinogen and mutagen, so food with determinable residues of ethylene oxide are classified as a health hazard.
The data situation for 2-chloroethanol, the legally relevant reaction product of ethylene oxide, is inconsistent and partly incomplete. No reliable statement can currently be made regarding the carcinogenic characteristics of 2-chloroethanol. There are numerous indications for genotoxic activity. However, the existence of a possible threshold value and the in-vivo relevance haven’t been definitively clarified. There is currently no evidence that 2-chloroethanol has a higher level of toxicity than ethylene oxide. As a precaution, therefore, the Federal Institute for Risk Assessment recommends in its current opinion statement of 20.11.2020 that the risk assessment for 2-chloroethanol should be conducted as that for ethylene oxide [9]. Foods are therewith also to be classified as unsafe if the given summed residue of ethylene oxide is solely based on findings of 2-chloroethanol. The BfR confirmed this assessment in response to a request by the NEM Association (for nutritional supplements) in June 2021 (not yet published) [11].
In view of the carcinogenic effects of ethylene oxide, the BfR established a benchmark dose (BMDL10) of 370 µg/kg body weight per day as a reference point for risk assessment. The BMDL10 describes the lower limit of the confidence interval for the dosage given in animal experiments that would cause promotion of a tumor in 10 % of the animals. By applying a Margin of Exposure (MOE) of 10,000, the intake amount of minimal concern for ethylene oxide was calculated as 0.037 µg/kg bodyweight.
Ad-hoc analysis of nutritional supplements and herbal powders: what were the results?
After the first two findings of very high levels of 2-chloroethanol in nutritional supplements were verified, CVUA Stuttgart initiated a short-term special research program in June 2021 to analyze a total of 135 samples of nutritional supplements, herbal powders and empty capsules for ethylene oxide and 2-chloroethanol.
Herbal powder – „Superfood“
Powder from plants and dried fruits – often with exotic origins – have been successfully sold for years under the legally unregulated marketing term „superfood“. As a general rule, „superfoods“ are only consumed in small amounts (spoonfuls), mainly in smoothies, but also in yogurts and breakfast cereals. They are also widely available as nutritional supplements in the form of capsules or tablets/pills.
We have reported several times in recent years that exotic superfoods were often not complying with regulations as regards pesticide residues and microbial contamination [12–14]. In our current project, we analyzed a total of 53 samples of herbal powders, such as barley grass, moringa, maca and psyllium husks. Three of these samples were exceeded the maximum residue limit for the sum of ethylene oxide and 2-chloroethanol (expressed as ethylene oxide): 1x moringa and 2x psyllium husks. Table 1 shows an overview.
| Category |
Number of Samples
|
Samples w/ 2 Chlorethanol
|
Assessment |
|---|---|---|---|
|
(thereof organic)
|
(thereof organic)
|
||
| Psyllium husks |
22 (9)
|
2 (0)
|
Exceedance of MRL |
| Maca powder |
9 (9)
|
0
|
|
| Moringa powder |
4 (4)
|
1 (1)
|
Exceedance of MRL, health hazard |
| Grass powder |
5 (3)
|
0
|
|
| Algae powder |
2 (2)
|
0
|
|
| Other* |
11 (6)
|
0
|
|
| TOTAL |
53 (33)
|
3 (= 5.7 %)
|
Of the 53 analyzed herbal powder samples, three (5.7 %) raised concern: moringa and psyllium husks. The organic products grown in the EU were did not raise any adverse attention.
Nutritional supplements in capsules
Herbal powders can also be consumed in the form of capsules. As seen on the shelves of supermarkets, drug stores and especially on the Internet, there is more than a wide range of offerings. It is in any case a huge business.
The ingredients lists sometimes read like a recipe for a magic potion out of Harry Potter:
like…
• shatavari root powder, HPMC, reishi mushroom, turmeric root extract, shatavari root extract, broccoli seed sprouts, extract from green tea leaves, maca root extract, ginger root, aloe vera juice concentrate, seaweed, spirulina
or
• horse chestnut seed extract, red wine leaf extract, HPMC, grapeseed extract, rutin powder, bamboo extract, calcium ascorbate, vitamin E, butcher’s broom root extract.
The suggested effects cover a range wide enough to please everyone: joints, veins, the immune system, eyes, women problems, libido – there is a capsule for almost everything. We find, however, that consumers should give considerable thought to whether such compositions of ingredients make sense.
We have currently analyzed 40 samples of nutritional supplements in capsule form for residues of ethylene oxide and 2-chloroethanol and come up with some surprising results.
Separate investigations into capsule husks (empty capsules) and their contents revealed that, with certain products, the husks were contaminated but not the contents. Without exception these were made from the additive hydroxypropylmethylcellulose (HPMC, E 464).
Due to the increasing popularity of eating vegan, nutritional supplements with powder ingredients are now mostly offered in the form of HPMC instead of gelatine capsules. If taken in moderate amounts, the consumption of HPMC, which is indigestible for humans, is not a health concern.
The assessment and also the determination of causation are much more difficult for samples containing complex combinations of ingredients, however, especially when not only the capsule husk but also the contents show positive findings.
In view of the world-wide marketing channels, tracing the sources of ingredients in such complex compositions as depicted above presents a challenge for the responsible enterprises.
Table 2 presents the analytical results of the 12 positively tested capsules. The findings are presented separately, for the whole capsule, the capsule contents and the capsule husk. Thirty percent of the analyzed samples were positive; 6 cases were judged to be hazardous for consumption. Some of the 2-chloroethanol amounts came from the capsule, some from the powder, and in some cases both components seemed to be contaminated. Since there is an inner connection between the capsule and its contents where a material exchange occurs, only an examination of the raw materials can give absolute clarity.
| Sample |
Detected amount of 2-Chloroethanol
|
Calculated amount of ethylene oxide
|
Organic/ Conventional
|
Assessment |
|---|---|---|---|---|
|
[mg/kg]
|
[mg/kg]
|
|||
| Barley grass capsules |
177
|
96.8
|
Organic
|
Hazardous to health, Exceedance of MRL |
| · barley grass powder contained thereof |
37.3
|
20.4
|
||
| · empty capsules (from HPMC) |
698
|
384
|
||
|
|
|
|
||
| Moringa capsules |
3.716
|
2.035
|
Conventional
|
Hazardous to health, Exceedance of MRL |
| · moringa powder contained thereof |
4.040
|
2.210
|
||
| · empty capsules (from gelatine) |
3.065
|
1.686
|
||
|
|
|
|
||
| Red maca capsules |
1.6
|
0.88
|
Organic
|
Notice Food Additive Legislation |
| · red maca powder contained thereof |
0.37
|
0.2
|
||
| · empty capsules (from HPMC) |
7.8
|
4.3
|
||
|
|
|
|
||
| Women’s health capsules |
3.2
|
1.8
|
Conventional
|
Notice Food Additive Legislation |
| · Powder mixture from various plant parts contained thereof |
0.8
|
0.44
|
||
| · empty capsules (from HPMC) |
Not carried out
|
|||
|
|
|
|
||
| Milk thistle capsules |
1.3
|
0.71
|
Organic
|
Notice Food Additive Legislation |
| · powder contained thereof |
0.11
|
0.06
|
||
| · empty capsules (from HPMC) |
6.9
|
3.8
|
||
|
|
|
|
||
| Prickley pear blossom capsules |
144
|
79.2
|
Conventional
|
Hazardous to health |
| · powder contained thereof |
49.7
|
27.2
|
||
| · empty capsules (from HPMC) |
480
|
264
|
||
|
|
|
|
||
| Turmeric capsules |
0.4
|
0.22
|
Organic
|
Notice Food Additive Legislation |
| · empty capsules (from HPMC) |
2.4
|
1.3
|
||
| · powder contained thereof |
Not carried out
|
|||
|
|
|
|
||
| Capsules for veins |
204
|
112
|
Conventional
|
Hazardous to health |
| · powder contained thereof |
164
|
89.8
|
||
| · empty capsules (from HPMC) |
374
|
205
|
||
|
|
|
|
||
| Capsules for joints |
127
|
69.3
|
Conventional
|
Hazardous to health |
| · powder contained thereof |
10
|
5.4
|
||
| · empty capsules (from HPMC) |
777
|
425
|
||
|
|
|
|
||
| Capsules for immunity |
2.5
|
1.4
|
Conventional
|
Notice Food Additive Legislation |
| · powder contained thereof |
2.3
|
1.3
|
||
| · empty capsules (from HPMC) |
4
|
2.2
|
||
|
|
|
|
||
| Lactobacteria capsules |
0.17
|
0.1
|
Conventional
|
Notice Food Additive Legislation |
| · empty capsules (from HPMC) |
0.55
|
0.3
|
||
| · powder contained thereof |
Not carried out
|
|||
|
|
|
|
||
| Ashwaghanda capsules |
21.5
|
11.8
|
Conventional
|
Hazardous to health |
| · powder contained thereof |
9.7
|
5.3
|
||
| · empty capsules (from HPMC) |
103
|
56.3
|
||
Empty capsules made of hydroxypropylmethylcellulose (HPMC)
Due to our results for nutritional supplements in capsules, we also analyzed empty capsules: 10 samples were ordered via the Internet and further samples were taken from nutritional supplement contract manufacturers. A total of 21 samples of empty capsules made of HPMC and two samples of HPMC powder were investigated.
Three of the empty capsule samples showed positive findings for 2-chloroethanol. The detected quantities of 2-chloroethanol ranged from under 1 mg/kg to over 500 mg/kg. With such high amounts as 500 mg/kg, consuming just one capsule a day would already put one over the “intake amount of minimal concern” indicated by the BfR.
The certificates presented to us for the empty capsules increasingly showed that cellulose extracted from wood was the raw material most commonly used in the production of HPMC.
Info Box
Production of the additive HPMC (E 464)
HPMC is produced from cellulose by means of a so-called etherification procedure, where organic chemicals are put under drastic chemical-physical conditions.
HPMC is sold, depending on the desired technological characteristics, in various grades of polymerization and substitution [15,16].
HPMC serves myriad technological purposes as a food additive; besides as a coating, it is also used as a filler, thickener, stabilizer, carrier, and emulsifier [16]. In the pharmaceutical realm the substance is known by the designation „hypromellose“. In many cases HPMC is mixed with other substances, such as polyethylene glycol and carrageenan.
Certificates alone do not offer nutritional supplement producers sufficient protection. The certificate for two rather inconspicuous empty capsules, for example, stated that no application of ethylene oxide had been made. One of the samples with a Korean certificate stating „no Ethylene Oxide“ was, however, highly contaminated.
The path from tree to capsule husk is sometimes very far: pine wood fibers from the east coast of the U.S. are sent to Korea to be processed into HPMC powder, which is then sent on to China to produce capsule husks. These arrive at a nutritional supplements producer in the German Federal State of Baden-Württemberg by means of an Austrian importer. With so many and such widespread stations, tracing the cause of contamination is certainly very difficult. Moreover, the information disclosed in these certificates is alarming in terms of the negative ecological footprint of such capsules, the circumstances of which are most likely not known to many consumers.
Nutritional supplements in the form of pills
Based on the afore-mentioned analytical results, we found it urgently necessary to also investigate nutritional supplement products in tablet or pill form, where HPMC was listed in the ingredients label.
We very quickly hit the jackpot with some commonly sold mineral and vitamin preparations. HPMC was mentioned in all of the ingredients lists for the positive samples; depending on the product, there was also a whole string of other ingredients declared, including other (modified) celluloses: microcrystalline cellulose (E 460 (i)), hydroxypropyl cellulose (E 463), cross-linked sodium carboxymethyl cellulose (E 468) and cellulose (E 460 (ii)). See Info Box.
Info Box
Cellulose ethers as food additive
In addition to HPMC (E 464), a series of so-called “modified celluloses” are also used in foods, produced via etherification (additives E 461 to E 469).
Modified cellulose is permitted for many foods. With few exceptions, the substances may be used „quantum satis“. That means there are no concrete limitations given, but the substances should only be used in amounts that are necessary for achieving their technological purpose.
A total of 19 pill samples were analyzed, mainly mineral and vitamin preparations. Reports were generated for 6 of the samples (2 preparations were analyzed twice, from different batches). The quantity detected was between 2 and 11 mg/kg pills which, depending on the recommended daily intake, already exceeded the toxicological threshold (“intake amount of minimal concern”).
What we found – summary
Among 135 samples of plant powders, nutritional supplements with hydroxypropyl-methylcecllulose (HPMC) and empty capsules made of HPMC, 24 samples (18 %) were found being conspicuous as regards ethylene oxide residues. The individual product groups were affected differently, however:
- Plant powder – superfood: 5.7 %
- Nutritional supplements in capsules: 30 %
- Empty capsules 14 %, and
- Nutritional supplements as pills/tablets (6 samples comprise 4 cases): 21 %.
What is still to be done?
The responsible food companies and the official food controllers are taking the necessary steps to remove the affected batches from the market. Moreover, the affected food companies but also the industry itself is required to determine the causes for the presence of ethylene oxide / 2-chlorethanol in the production chain and to improve their own measures of control to the extent necessary.
Analysis of these products will continue on a routine basis, although we intend to strengthen our focus on ingredients from non-EU countries and on food additives as such.
Info Box
EU-Food law: Responsibility of Food Companies
Foods that do not comply with requirements for food safety may not be marketed (Article 14 of the Basic EU Food Safety Regulation 178/2002/EC [20]). In addition, Article 19 stipulates that the responsible food companies are obliged to act: they must immediately initiate the removal of such food from the market shelves. If the product could have already reached the consumer, the company must effectively and precisely inform consumers as to the reason for the product recall and, if necessary, send out a recall notice, if other measures for achieving a high level of health do not suffice.
What do these results mean for you as a consumer?
There have already been some recalls and we anticipate further recalls of affected products. For your own protection, you can see these on the portal for food warnings (www.lebensmittelwarnung.de), at RASFF portal.
It’s obvious that there is a bigger health risk associated with unwanted substances from plant parts being imported from all over the world than with regional products. Locally grown superfoods boom especially during summer! The consumer advice center lists some delicious and affordable alternatives [17]. Don’t be fooled by exaggerated claims of efficacy for nutritional supplements! There are many dubious offers on the Internet, especially now in this time of Corona – we are reporting on these [18]. Nutritional supplements can be useful if they are taken properly, but not for everything and not for everyone [19].
Thanks
We are very grateful to our „Pestis“ team and the lab’s plant-based foods team for their engagement and flexibility in administrating and analyzing the many extra samples along with their routine activities. In so doing, they have made an important contribution to the protection of consumer health! Our thanks are also extended to the responsible officials on-site, who collected the special samples and carried out the implementation of these measures.
Photos
Andrea Karst, CVUA Stuttgart
References
[1] CVUA Stuttgart: Lieber "Kemie" statt Keime? - In der EU ist beides nicht zulässig
[2] Durchführungsverordnung (EU) 2020/1540
[3] Government of Canada: Proposed Maximum Residue Limit PMRL2019-29, Ethylene Oxide, accessed on 25.11.2020
[4] Health Canada – MRL Database (Auswahl: Ethylene Oxide & Sesame seeds), accessed on 25.11.2020
[5] Spezifikationsverordnung für Lebensmittelzusatzstoffe: VO (EU) Nr. 231/2012
[6] Verordnung zur Durchführung unionsrechtlicher Vorschriften über Lebensmittelzusatzstoffe
[7] Analysis of ethylene oxide and 2-chloroethanol in oily seeds using QuOil and QuEChERS in combination with GC-MS/MS; Analytical Observations Report
[8] Amtliche Sammlung von Untersuchungsverfahren nach § 64 LFGB: ASU L 13.04-5 2013-08 (QuOil), ASU L 00.00-115 2018-10 (QuEChERS)
[9] BfR-Stellungnahme zur Toxizität von Ethylenoxid und 2-Chlorethanol, hier: Funde in Sesamsamen und in hieraus hergestellten Erzeugnissen vom 20.11.2020, Az. 30-0202-01-11345065 – veröffentlicht als BfR-Stellungnahme Nr. 056/2020 vom 23.12.2020, hier: Gesundheitliche Bewertung von Ethylenoxid-Rückständen in Sesamsamen
[10] ECHA - Einstufung von Stoffen und Gemischen, accessed on 25.11.2020
[11] Stellungnahme des BfR zur toxikologischen Bewertung / Expositionsschätzung zu 2-Chlorethanolfunden in mit Guarkernmehl hergestellter veganer Wurst und in Nahrungsergänzungsmitteln vom 17.06.2021 (Az. 30-0301-06-11578895, bislang nicht veröffentlicht)
[12] CVUA Stuttgart: „Superfood“ – hält nicht, was der Name verspricht
[13] CVUA Stuttgart: Moringablattpulver – weiterhin mit Rückständen und unlauterer Bewerbung
[14] CVUA Stuttgart: Moringa oleifera – ein Update
[15] Wikipedia: Cellulosederivate
[16] Wikipedia: Hydroxypropylmethylcellulose
[17] Verbraucherzentrale Bundesverband: Superfood: Diese Alternativen sind gesund und günstig
[18] CVUA Stuttgart: Nahrungsergänzungsmittel gegen Corona - Die Werbetricks der Online-Händler
[19] Verbraucherzentrale Bundesverband: Nahrungsergänzungsmittel richtig verwenden
[20] Verordnung (EG) Nr. 178/2002 des Europäischen Parlaments und des Rates vom 28. Januar 2002 zur Festlegung der allgemeinen Grundsätze und Anforderungen des Lebensmittelrechts, zur Errichtung der Europäischen Behörde für Lebensmittelsicherheit und zur Festlegung von Verfahren zur Lebensmittelsicherheit
Translated by: Catherine Leiblein
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