1. Ban of Potassium Dichromate under REACH in relation to COD used in the UWWTD 91/271
Christof Mainz
European Commission
Directorate General for the Environment
unit C.2 – Marine Environment & Water Industry

2. Current regulation UWWTD 91/271/EEC

3. REACH Regulation
REACH regulation (EU) No 348/2013 of 17 April 2013 is amending Annex XIV to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH):
 (6) Potassium dichromate meets the criteria for classification as carcinogenic (category 1B), mutagenic (category 1B) and toxic for reproduction (category 1B) in accordance with Regulation (EC) No 1272/2008 and therefore meets the criteria for inclusion in Annex XIV to Regulation (EC) No 1907/2006 set out in Article 57(a), (b) and (c) of that Regulation.

4. REACH Regulation
(14) Concerning the seven chromium compounds, the Agency proposed the latest application date to be set at 21 months after entry into force of this Regulation. However, based on a discussion with Member States, a broader appreciation of the significance of the specific structure of the relevant markets and the related supply chains leads to the conclusion that the latest application date should be set at 35 months after entry into force of this Regulation.
 substance should not be placed on the market or used on its own, in mixtures or for incorporation into articles

5. REACH Regulation
(15) For each of the substances listed in the Annex to this Regulation the sunset date referred to in Article 58(1)(c)(i) of Regulation (EC) No 1907/2006 should be 18 months after the latest application date referred to in Article 58(1)(c)(ii) of that Regulation.

6. Mn III COD Cr VI COD BOD Comparing Typical Results:
Mn (III) COD developed as a less hazardous way to obtain an Oxygen Demand result in 1 hour at 150C; the selectivity is different than either BOD or Cr(VI) COD.
Typically 1 hour
Mn III COD
Comparing Typical Results:
BOD ≠ Cr VI COD ≠ Mn COD
Results are based on Cr(VI) oxidation (digestion) of the sample at 148°C, 2 hours. Developed to be a replacement to BOD, but selectivity is not same as BOD.
Typically 2 hours
Cr VI COD
Typically 5 days
Results are based on biological digestion of sample – selective oxidation, slow process requiring incubator.
BOD

7. Total Oxidizable Carbon - TOC
TOC is not influenced by H, N, P and S in sample. COD methods are influenced by H, N, P, S, O in sample.
Total Oxidizable Carbon - TOC
Carbon Dioxide
Oxidizable Carbon:
Carbon Dioxide evolves from Sample
Typically 5 to 60 minutes
Results are based on chemical digestion (oxidation) of sample with a persulfate reagent at ° C – carbon content in the form of evolved carbon dioxide is measured; influence due to selectivity is typically less than Oxygen Demand methods.
Sample that may contain:
a wide variety of compounds built from H, C, N, P, S, O
Comparing Typical Results:
TOC x factor ≠ Cr IV COD ≠ Mn COD

8. Possible Solution
COD still reflects the standard of 1991 when the Directive was published.
A change for another reference method is possible, under legal and technical aspects.
TOC is easier, cheaper and quicker and without use of hazardous chemicals or heavy metals.
Working group established under the UWWTD: UK, NL, DE, BE, SE, COM (DG ENV, JRC)

9. Solution for discussion: DRAFT - Revised Table 1
Parameters
Concentration
Minimum percentage of reduction (1)
Reference method of measurement
 COD
Total organic carbon (TOC) (2)
125 mg/l
30 mg/l 75 80
Potassium dichrom.
EN 1484
(2) COD measures … may be used until 31 Dec 2020 to establish a COD-TOC ratio for a wwtp for modelling purposes only.

10. For discussion
Send comments / suggestions via to:
by 30 Mar 2016 at the latest

11. Thank you for your attention.