8/7/12

Interagency Comments on Chromium Electroplating RTR Final Amendments and EPA Responses

1. EPA has provided new data on the behavior of non-PFOS fume suppressants (FS) in the memo titled 

Information on non-PFOS Fume Suppressants in Minnesota Chromium Electroplating Facilities. 

Although this data appears to support EPA’s position that non-PFOS FS are cost-effective 

replacements for FS with PFOS, Advocacy staff wanted to note that the data has not been seen by the 

public and has not been subject to a notice and comment period. Advocacy staff suggest that EPA 

issue a Notice of Data Availability (NODA) to provide the public with an opportunity to comment on 

the newly collected data.

EPA Response: As suggested during our call last week, we placed this memorandum in the docket. 

However, we do not believe it is necessary to issue an NODA because the data supports our decision 

regarding the phase-out of PFOS and the costs and effectiveness of non-PFOS fume suppressants. It is 

common that EPA receives additional data between proposal and final rulemakings and EPA considers 

these data and information in the development of the final rulemakings, as appropriate. 

2. Question regarding Attachment 3 to Information on non-PFOS Fume Suppressants in Minnesota 

Chromium Electroplating Facilities: What other conclusions can be drawn about the relationship 

between FS and surface tension from this spreadsheet besides that the surface tension has remained 

under 33 (surface tension limit if measured with a tensiometer)? For instance, some days it takes 

twice the amount of FS to achieve the same surface tension level e.g. 5/2/2012 and 5/3/2012 or 

4/17/2012 and 4/18/2012. 

EPA Response: The amount of fume suppressant that must be added to the tank to meet the surface 

tension limits is a function of production rate. Although fume suppressants degrade over time and 

must be replenished, there are more significant losses due to dragout, which refers to the liquid that 

remains on parts when the parts are removed from the tank. During periods of high production, 

electroplating rates are higher and more liquid is lost through dragout. The most likely explanation for 

the higher additions of fume suppressant on 4/17 to 4/18 and 5/2 to 5/3 is the production rates were 

much higher those days.

3. Does EPA have any data that contradicts the finding in the new German FS suppressant study 

performed by Merck that demonstrates that there is no correlation between surface tension level and 

emissions level?

EPA Response: As an initial matter, we disagree that the German study demonstrates that there is no 

correlation between surface tension and emissions levels. The report from the German Study includes 

very little documentation, and we question the representativeness of the test vessel and the 

appropriateness of the test method and procedures used. For example, we question whether they used 

valid emissions test methods. The German Study report also does not provide surface tension data and 

it is unclear if surface tension levels were measured during the testing. It also should be noted that the 

German Study Report draws no such conclusions about the relationship between surface tension and 

emissions. The only relevant conclusions presented in the report is that both the PFOS and non-PFOS 

commercially available fume suppressants achieve more than 95% control of chromium emissions, and 
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that the new experimental chemical (which is not commercially available and not really a fume 

suppressant) achieved no reductions. Obviously there is a problem with this new experimental chemical 

and it would not make it to the market as a fume suppressant.

With regard to data that support the effectiveness of non-PFOS in controlling emissions, we have 

attached a summary of a 2011 Danish Study (Danish, EPA. 2011) and a comparison of that study to the 

German Study. We believe the Danish Study is more representative of actual electroplating operations 

and used more appropriate methods for quantifying emissions. Although this study also did not report 

surface tension measurements, the results indicate that non-PFOS fume suppressants are as effective as

PFOS fume suppressants in controlling chromium emissions.

4. Please find attached a marked-up copy of the Cr Electroplating Industry Profile 6.27.12 document 

showing the facilities for which the NASF and EPA data differs. Does EPA believe that the NASF data is 

reliable and will EPA update this spreadsheet to reflect the most current data for the docket?

EPA Response: We have reviewed the data from NASF and have updated our database and the profile 

with the NASF data, where appropriate. We did not accept some of the NASF emissions estimates 

because they were assumed by NASF as being either 10% or 33% or simulated emissions values from our 

database, and we conclude there is no support or basis for these values.

5. Page 125, Table 2 to 63.342, Subpart N, item 5, column 2: There are two item "(iv)"s. Delete the first 

"(iv) Other cleaning method approved by the permitting agency;" because is already covered in item 

"(v)". 

EPA Response: We have incorporated this change into the preamble.

6. For consistency EPA should revise section 63.342(c)(2)(iv) by changing "are affected sources other 

than those that are existing affected sources located at small hard chrome plating facilities" to "are 

existing affected sources and are located at large hard chrome plating facilities" and by revising 

section 63.344(f)(i)(A) by changing "an affected source other than an existing affected source located 

at a small hard chromium electroplating facility" to "an existing affected source located at a large hard 

chrome plating facility." We are referring to the text in the rule that is not currently being revised by 

EPA. EPA made this change in section 63.342(c)(1)(iii) and section 63.342(c)(2)(i). It is definitely clearer 

to say a requirement applies to large facilities rather than saying it applies to everything other than 

small facilities.

EPA Response: We have incorporated this change into the preamble.

7. We would suggest that EPA consider adding some explanation in the discussion about the 

multipathway analysis on why chemicals that are not PB-HAP are unlikely to present non-inhalation 

risks. 

EPA Response: This question was discussed during the conference call on 8/2/12. We have inserted 

text into the preamble to address this comment.
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8. Did EPA consider monetizing benefits associated with reduction in cancer risks? 

EPA Response: As discussed during the conference call on 8/2/12, because the rule is not economically 

significant, EPA did not consider monetizing benefits associated with reduction in cancer risk. In 

addition, the Agency currently does not have a sufficiently developed methodology to monetize those 

benefits.

Reference:

Danish, EPA. 2011. Substitution of PFOS for use in non-decorative hard chrome plating. Pia Brunn 

Poulsen, Lars K. Gram and Allan Astrup Jensen. Danish Environmental Protection Agency. Environmental 

Project No. 1371 2011. 
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Comparison of German and Danish Studies on Non-PFOS Performance

Item German Study Danish Study Remarks

Process type Hard Cr Hard Cr For both studies, current density was 50 A/dm2

Plating Tank Volume, gallons 1.2 29 German Study was lab-scale; Danish Study was full scale 

(although the tank was small)

PFOS product HSO FL Fumetrol 140

Non PFOS product Fumetrol 21 Fumetrol 21

Surface tension Not specified (a) Not specified (b) No surface tension measurements reported. See Notes (a) and 

(b) below for estimated surface tensions

Test Method EN 15205 (c) EN 14385 (d) Method used for German study was not meant for quantifying 

emissions and is a “qualitative” method; Method used for Danish 

Study is meant for quantifying stack emissions

No. of test runs PFOS: 2

Non-PFOS: 3

PFOS: 5

Non-PFOS: 5

Danish Study included more test runs

Test run duration, hours 33 to 50 1,440 Given the lab scale size, it is difficult to believe the test run 

durations for the German Study were adequate; for the Danish 

Study, test runs were each 24 hours

Detection limit, ug/m3 Not specified 0.9

Average Cr Concentration, mg/dscm

PFOS 0.0065 0.0218 For German Study, PFOS performed better; for Danish Study, 

Non-PFOS 0.0266 0.0067 non-PFOS performed better

(a) Study included calibration curves that relate fume suppressant concentration and bubble lifetime to surface tension, but it is unclear how 

the calibration curves were used; report states that PFOS and non-PFOS chemical concentrations were in accordance to manufacturer’s 

specifications; based on Fumetrol 21 data sheet and reported concentration during test (2.0 to 2.5 ml/L), the surface tension should have been 

about 33 to 37 dynes/cm for the non-PFOS fume suppressant test (not 30 dynes/cm as suggested by NASF).

(b) Report states that both PFOS and non-PFOS chemical concentrations were 50% more than manufacturer’s specification; based on Fumetrol 

21 data sheet and reported concentration during test (3.6+ ml/L), the surface tension should have been about 26 to 28 dynes/cm for the nonPFOS fume suppressant test.

(c) DIN EN 15205, Determination of hexavalent chromium in corrosion protection layers - Qualitative analysis

(d) BS EN 14385:2004, Stationary source emissions. Determination of the total emission of As, Cd, Cr, Co, Cu, Mn, Ni, Pb, Sb, TI and V