Page 1 of 9 OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

June 28 , 2010

MEMORANDUM

S ubject : Occupational and Residential Exposure and Ris k Assessment for the

New Active Ingredient N, N’

- methylenebis (5

- methyloxazolidin) (Stabicide 71 )

F rom : Timothy C. Dole, CIH, Industrial Hygienist

Risk Assessment and Science Support Branch (RASSB) Antimicrobials Division (7510P)

T hrough : Timo thy Leighton

, Senior Scientist

Risk Assessment and Science Support Branch (RASSB) Antimicrobials Division (7510P)

And

Nader Elka ssa

ba n y Ph.D., Chi e f

R isk Assessment and Science Support Branch (RASSB) Antimicrobials Division (7510P)

T o : Dennis Edwards , Chief

Marshall Swindell, Product Manager, Team 33 Regulatory Management Branch I Antimicrobials Division (7510P)

DP Barcodes: D360880

Chemical: N,N’

- methylenebis (5

- methyloxazolidin)

PC Code: 114804

Registrant: S chulke & Mayr GmbH

The Antimicrobial Division’s (AD) Regulatory Management Branch I has requested that the Risk Assessment and Science Support Branch (RASSB) conduct exposure and risk

assessments to evaluate the application for registration of Stabicide 71 , which contains a new

active in gredient N,N’

- methylenebis (5

- methyloxazolidin)

.Page 2 of 9

Executive Summary

Stabicide 71 (i.e. N, N’

- methylenebis

- 5

- ( methyloxazolidin )) is proposed for use as a preservative to control non

- public health bacteria and some fun gi in metal working fluids, water based drilling muds and diesel fuels. It is anticipated that workers will experience dermal and inhalation exposure to Stabicide 71 and it’s degradate, formaldehyde, as a result

of these uses.

The toxicology database f or Stabicide 71 includes an acute dermal toxicity study, three mutagenecity studies

, a n oral prenatal developmental study in rabbits and a 90 oral toxicity study in rats. Because the database is limited and does not include inhalation or dermal studies, endpoints could not be selected for risk assessment for these routes of exposure. These endpoints will be selected once the required studies are submitted and reviewed.

Hydrolysis data indicates N, N’

- methylenebis (5

- methyloxazolidin) degrades to

formal dehyde with a half life of less than one hour (US EPA, 2010), therefore, the risk of formaldehyde inhalation exposure was also assessed. To assess non

- cancer risks, an inhalation RfC of 0.1 ppm (i.e. 100 ppb) was derived from a NOAEL of 0.1 ppm for peak exposures that was selected from literature studies where respiratory irritation was observed in workers exposed to formaldehyde. Cancer risks were assessed using a unit risk of 1.3 x

10 - 5 per ug/m 3 from IRIS and results of CIIT model runs as presented i n Conolly et. al. 2004.

There are no exposure data available for Stabicide 71 for machining operations . Based on the exposure data for a related chemical

, HHT, however, it is likely that formaldehyde exposures resulting from the use of Stabicide 71 in M WF will exceed the level of concern of 100 ppb

. The exact magnitude of the se exceedances cannot be predicted from the available

data because the sampling times generally ranged from 3 to 4 hours while peak exposures are normally measured with sampling tim es of 15 minutes or less . Since many of these results exceed the level of concern of 100 ppb as a 3 to 4 hour average; however, it can be assumed

that 15 minute samples taken within the same 3 to 4 hour time period would have also exceeded 100 ppb. It is also possible that the 3 to 4 hour samples which were below 100 ppb contained one or more 15 minute periods of exposure that exceeded 100 ppb.

Handlers will be exposed to formaldehyde during the addition of Stabicide 71 to drilling

muds and diesel fue ls. There are no exposure data available for Stabicide 71 for these

scenarios. The intensity of these exposures will depend upon the method of addition and the

c onfiguration of the process. If Stabicide 71 is added by open pouring into an open process with minimal engineering controls, then formaldehyde exposures could exceed the RfC of 100 ppb. Conversely, if Stabicide 71 is added using closed system transfer to processes that have engineering controls to prevent emissions, then it is possible that f ormaldehyde exposures would not exceed 100 ppb.

If workplace conditions are maintained such that peak exposures do not exceed 0.1 ppm, daily average exposures will be at least 3 times less than 0.1 ppm because workplace exposures from even the most wel l controlled processes have a within day variability of at least 3. If it assumed that workers are exposed to averaged daily concentration of 0.03 ppm for 240 days per year and 35 years per 70 year lifetime, the cancer risk ranges from

2.2 x 10 - 8 to 5. 8 x 10 - 5 depending upon which calculation method is used (IRIS or CIIT).Page 3 of 9

1.0 Product Use Profile:

Stabicide 71 is a formaldehyde releasing preservative that contain s a new active ingredient, N,N’

- me thylenebis (5

- methyloxazolidin) at a purity of 9 9

. 09 % a.i. It is proposed for use as a preservative to control non

- public health bacteria and some fungi in metal working fluids , water based drilling muds and diesel fuels

. The application rates are 500 to 2000 ppm for all three uses though a lower use rate o f 50 to 200 ppm is also listed for preventive treatment of diesel fuel.

2 .0 Summary of Toxicological Endpoints :

Because N,N’

- methylenebis (5

- methyloxazolidin) is a formaldehyde releaser, the toxicity of both the parent compound and the formaldehyde that i s released from the parent compound

must be considered.

2 .1 N,N’

- methylenebis (5

- methyloxazolidin)

A summary of the toxicity data that has been submitted for N,N’

- methylenebis (5

- methyloxazolidin) is incl uded in D360405 (EPA, 2009) . These studies in clude an acute dermal toxicity study, three mutagenecity studies, a n oral prenatal developmental study in rabbits and a 90 oral toxicity study in rats. There are no inhalation or dermal studies

available for N,N’

- methylenebis (5

- methyloxazolidin) . D3604 05 also includes a listing of the studies that are required for the registration of N,N’

- methylenebis (5

- methyloxazolidin)

, and this list includes dermal and inhalation toxicity studies. Endpoints will be selected for risk assessment upon receipt and revi ew of these studies.

2 .2 Formaldehyde

Hydrolysis data indicates N, N’

- methylenebis (5

- methyloxazolidin) degrades to formaldehyde with a half life of less than one hour (US EPA, 2010). This degradation occurs through a number of steps and includes the formation of Hexahydro

- 1,3,5

- tris (2

- hydroxypropyl)

- s

- triazine.

Table 1 .0 summarizes the toxicological endpoints for formaldehyde which are described in more detail in following memorandum: " Formaldehyde/Paraformaldehyde

- Report of the

Antimicrobials Div ision Toxicity Endpoint Selection Committee (ADTC) ” from T. McMahon to S. Carlisle, dated June 24, 2008. Endpoints were selected only for assessing inhalation

exposures to formaldehyde and it was determined that assessments of the other routes of

exposur e (dietary, dermal and incidental oral) would not be not required. In addition, the following disclaimer from the “ Response to Public Comments on the Formaldehyde Preliminary Risk Assessment RED ” from T. McMahon and T. Dole to S. Carlisle, dated January

, 6, 2009 is provided for the non

- cancer formaldehyde endpoint:

OPP developed the formaldehyde inhalation non

- cancer toxicological endpoint used in this document through the established registration process, which includes stakeholder consultation and publ ic comment. However, the result has not been subjected to an inter

agency review or external peer review. Because of time constraints imposed by statutory deadline, OPP could not consider all available peer reviewed science (for example, the

intentional h uman dosing toxicity studies). Thus, this value should be considered an interim value, developed solely for the purposes of this determination and subject to future revision and subsequent peer review and should not be used in other contexts as EPA's opin ion of the

best available science on the non

- cancer effects of formaldehyde.Page 4 of 9

For the purposes of this assessment, the formaldehyde endpoints are expressed as RfCs which are the NOAEL divided by the uncertainty factor (UF). The UF is 1 for the occupation al exposures because the NOAEL was derived from observational studies of workers exposed to formaldehyde and the UF is 10 for the residential exposures to account for the increased sensitivity of some members of the residential population. It is also impo rtant to note these RfCs are for peak exposures.

The range of potential cancer risks were bracketed using the biologically based CIIT model (Conolly, 2004) and the upper bound cancer risks from IRIS reflecting default linear extrapolation. The CIIT model cancer risks were taken from Table 8 of Conolly, 2004.

Table 1

- Summary of Toxicological Doses and Endpoint Selection for Formaldehyde

Exposure

Scenario Dose Used in

Risk Assessment Reference Concentration (RfC) Study and Toxicol ogical Effects

Inhalation (all durations) NOAEL (human)

= 100 ppb RfC occupational = 100 ppb

RfC residential = 10 ppb

Where:

RfC = NOAEL

UF

UF = 1 for occupational

UF = 10 for residential ACGIH 2001

, TLV Documentation for

F ormaldehyde

Ho rvath, E.P. et al. (1986): JAMA 259(5): 701

- 707. Based on complaints of eye, nose, and throat irritation in particle board workers at formaldehyde concentrations of 0.4

– 1.0 ppm.

Redden, J. (2005): Section 18 Emergency Exemption for the use of Paraform aldehyde: U.S. Army Medical Research Institute of Infectious

Diseases.

Cancer Lifetime extra cancer unit risk estimate of 1.3  10 - 5 per  g/m 3 ( US EPA IRIS

http://www.epa.gov/ncea/iris/subst/0419.htm )

And

CIIT modeling : Tables 8A (for residential) and B (for professional). Hockey stick

- shaped CRCP (nonsmoking) (Conolly, 2004)

2 .3 Comparison to Other Formaldehyde Endpoints

The Occupational Health and Safety Administration (OSHA) issued the formaldehyde standard as a final rule on May 27, 1992. This standard includes a Permissible Exposure Limit (PEL) for formaldehyde of 0.75 ppm as an eight hour time weighted average (TWA) and 2 ppm as a 15 minute short term exposure (STEL). This means that 8 hour TWA formaldehyde exposures cannot exceed 0.75 ppm a nd 15 minute exposures cannot exceed 2

ppm. Since 1992, the American Conference of Governmental Hygienists (ACGIH) has recommended a threshold limit value (TLV) of 0.3 ppm as a ceiling (C) value. A TLV

Ceiling is an exposure limit that should not be ex ceeded at any time during the workday and is normally assessed as a 15 minute exposure. According to ACGIH “The recommended

TLV

- Ceiling of 0.3 ppm for workplace air formaldehyde is based on evidence of irritation from reports of occupational exposure to f ormaldehyde as well as human formaldehyde exposures in other settings. This recommended TLV may not eliminate all worker complaints of sensory irritation associated with exposure to this chemical. However, ACGIH believes that the 0.3 ppm ceiling value sh ould result in a significant reduction of complaints currently associated with exposure to formaldehyde”.Page 5 of 9

3 .0 Exposure Assessment for Non

- Cancer Risks

Because the proposed uses Stabicide 71 are limited to industrial environments, only the occupationa l Rf

C of 100 ppb is applicable to exposure assessment for non

- cancer risks

. There are three occupational exposure scenarios that involve the use of Stabicide 71. These scenarios include: (1) Metal Working Fluid Treatment, (2) Drilling Mud Treatment and (3)

Diesel Fuel Storage Tank Treatment.

3

. 1 M etal Working Fluid Exposures

Contram ST

- 1 is proposed for use in metal working fluids ( MWF ) at a maximum rate of 2000 ppm and this use will likely result in exposures to formaldehyde. Since formaldehyde

h as a significant vapor pressure ( 1 mm Hg at 25 C as formaldehyde in formalin) , the vapor inhalation exposure is the primary route of exposure . Inhalation exposure to the vapor is considered to be representative of exposure to the MWF aerosols containing f ormaldehyde as well as formaldehyde vapor s that evaporate from MWF

.

Exposure Data

No data have been submitted regarding the potential formaldehyde exposures during the use of MWFs treated with Stabicide 71. There are data available, however, from two studies

on Hexahydro

- 1,3,5

- tris(2

- hydroxy ethyl )

- s

- triazine (HHT) which is closely related to Hexahydro

- 1,3,5

- tris(2

- hydroxy propyl )

- s

- triazine which is a degradate of Stabicide 71 ( US EPA, 2010 )

. These studies were reviewed by AD in memo D345082 of June 3 0, 2008

a nd summaries are included below:

C ohen, 199 4

This study was conducted at a triazine formulation facility and at seven different manufacturing facilities that used triazine to treat metal working fluids (MWF). The manufacturing facilities inc lude d steel rolling mills, automotive transmission plants, industrial machinery manufacturers

, an automobile manufacture and two aluminum can

manufact u r er s. Personal breathing zone (PBZ) air samples were collected on the workers as they conducted normal p roduction operations such as tool setup, machining, grinding, steel rolling and aluminum can drawing and ironing using MWF treated with triazine. Samples were also taken during the addition of triazine which typically occurred in the middle of the

shift. Area samples were taken in the work areas near the employees and source samples were taken near potentially high exposure areas such as MWF sumps and return flumes. Background samples were also taken in areas such as adjacent office spaces to determine ambient formaldehyde levels that were not associated with MWF operations. Metal working fluid samples were taken from the sumps at each facility before and after triazine addition and were analyzed for triazine.

The PBZ samples were collected either wi th SKC silica gel tubes and/or GMD 570 passive badge dosimeters both of which were treated with 2, 4

- dinitrophenylhydrazine (DNPH). In many cases duplicate samples were taken using both methods. The samples were taken for 120 to 240 minutes each during MWF operations before and after triazine addition and for 5 to 27 minutes during triazine addition. Area, source and background samples were also collected also using midget impingers operated at a flow rate of 1 LPM in addition to the silica gel tubes an d passive dosimeters. The tube samples were analyzed using EPA Method #T011 and the impinger samples were analyzed using NIOSH MethodPage 6 of 9

#3500. The badge samples were analyzed by eluting acetonitrile and analyzing with HPLC

and UV detection. The limit of quantification (LOQ) for a 4 hour sample was 17 ppb, 18 ppb and 27ppb for the impingers, tubes and badge dosimeters, respectively. The LOQ for a 15 minute sample was 270 ppb, 297 ppb and 426 ppb.

Field recovery samples were generated by spiking with kno wn amounts of a solution of one microgram formaldehyde per microliter of water to approximate the quantities expected from a four hour sample at 100 ppb. The results indicated generally good recoveries with the exception of the badge dosimeters from site 3B which indicated an excessive recovery of 272%. This recovery was greater than the recovery of 103 % from site 3A or the average recovery of 113 % from all of the sites combined. There were only a few recoveries that

were less than 90% and these inclu de the two badge spikes from site 1 (58% and 64%) and 2 tube spikes from site 4 (67% and 80%).

A summary of the PBZ and background sample results is included in Table 2 . The results for the production operations ranged from non

- detect to a maximum of 4 90 ppb and many exceeded the 100 ppb level of concern. The highest results were from Site 3B which had good ventilation and few worker complaints. The PBZ samples for triazine addition are not included in the table because they were all less than the LOQ which ranged from 165 ppb to 930 ppb due the short sampling times. The background samples ranged from non

- detect to 118 ppb with the highest levels measured at sites 5 and 7.

Table 2

- Formaldehyde PBZ Air Concentrations Measured on Workers

Using Tri azine Treated MWF

Site Operation MWF Triazine Level (ppm) N Duration

(Minutes) Reported Values

(ppb) Background

Level (ppb)

1 Charging Reactor Drumming Triazine N/A 1

1 80

264 130

28 Not

Measured

2A Operator and Helper 550

, 1240 6 182 to 223 <19 to < 35 <20

2B Operator and Helper 0

, 220 5 179 to 223 <21 to 110 <20

3A Heat Treat Operator Lathe Operator

Grinder Machining Operator 0

, 400 1

1

6

7 117, 174
127, 172

1 10 to 172

1 09 to 166 <26 , <55

<26 , <36

<37 to < 58

<28 to < 56 <18

3B Machining Operator Maintenance Helper Pipefitter 1300 , 1400 8

2

3 1 44 to 212

206 , 146

47

- 223 1 4 0 to 4 9 0

250 , 410

140

- 340 <18

4A Worker in General Area Machinery Operator 1045 ,1685 2

1 162

- 242

211 ,161 52 , 106

154 ,257 28

4B Machinery Operators 1045 , 1685 6 1 53 to 236 1 0 2 to 1 63 28

5 Grinder Operators Machine Operators 586 to 1107 4

10 171 to 220

1 8 9 to 218 110, 130

55 to 2 50 78

6A Machine Operator Setup Operator 169 , 1894 4

4 160 , 236
236, 237 <18, 160

<18, 140 26

6B Grinder Operator 301 , 1847 4 175 to 208 <30 to 58 26

7 D& I Operator Washer Operator 997 , 1160 8

2 195 to 277

194 , 284 1 2 3 to 196

175 , 127 118

8 D & I Operator Line 1 975 , 1823 2 421 to 464 123 to 209 50 * Results highlighted in bold font exceed 100 ppbPage 7 of 9

Linnainmaa , 2003

This study was conducted i n 8 workplaces where hard metal or stellite blades were ground and 10 workplaces where general machining operations, such as grinding, turning, drilling, sawing and milling, were done. Seven different types of recirculating local exhaust ventilation syste ms were tested by measuring endotoxin concentrations in the exhaust air during the normal operation of the machines. Both personal and area samples were collected for formaldehyde using Waters Sep Pak silica cartridges treated with DNPH at a flow rate of

0.1 LPM for 2 to 4 hours. The concentration of triazine in the MWF was also measured in conjunction with the air sampling.

Twenty one personal samples were collected and the formaldehyde air concentrations ranged from 8.1 ppb to 179 ppb with a mean o f 42 ppb and a median of 20 ppb. Twenty seven area samples were collected and the air concentrations ranged from 6.5 ppb to 195 ppb with a mean of 45 ppb and a median of 17 ppb. The concentrations of triazine in the MWF ranged from <0.5 to 3500 ppm with a mean of 470 ppm

. The concentrations of triazine in the MWF correlated well with the formaldehyde concentrations in the air near the machines (n=23) with a correlation coefficient (R) of 0.69. The authors concluded that the triazine levels should be kep t above 500 ppm to prevent bacterial growth and that overdosing should be avoided to keep airborne formaldehyde levels low.

Machining Operations Exposure Assessment

Based on the exposure data from the Cohen and Linnainmaa studies it is likely that

formal dehyde exposures resulting from the use of Stabicide 71 in MWF will exceed the level of concern of 100 ppb , which is expressed as a peak value

. The exact magnitude of the exceedance cannot be predicted from the available data because the sampling times ge nerally ranged from 3 to 4 hours while peak exposures are normally measured with sampling times

of 15 minutes or less . Since many of these results exceed the level of concern of 100 ppb as a 3 to 4 hour average; however, it can be assumed that 15 minute s amples taken within the same 3 to 4 hour time period would have also exceeded 100 ppb. It is also possible that the 3 to 4 hour samples which were below 100 ppb contained one or more 15 minute periods of exposure that exceeded 100 ppb.

3

. 2 Drilling Mu d Exposures

Exposure to formaldehyde can occur during the addition of Stabicide 71 to drilling muds. Because formaldehyde has a high vapor pressure (1.0 mm Hg in formalin), the inhalation unit exposure data from PHED and CMA are not applicable because t hese data are based upon chemicals that have a much lower vapor pressure (less than 1.0 x 10 - 4 mm Hg). When the vapor pressure is less than 1.0 x 10 - 4 mm Hg, chemicals are airborne primarily as aerosols, while at a higher vapor pressure, chemicals are ai rborne primarily as vapors.

There are no exposure data available for Stabicide 71 for drilling mud operations; however, t he exposures to oil mist and vapor resulting from the use of oil based drilling muds during off

- shore drilling has been extensivel y studied in Norway (Steinsvag et al., 2006). This study indicated that rig type, technical control measures, and mud temperatures significantly determined exposure to oil mist while rig type, base oil type, base oil viscosity, work area and mud temperatu re and season determined exposure to oil vapor. The technicalPage 8 of 9

control measures mainly included cabins for the operators, more efficient ventilation systems and closing mud pits and fluids lines. Additional data regarding exposures to other

contaminants including formaldehyde from biocides are included a related study (Steinsvag et al., 2007). According to the 2007 study, formaldehyde levels measured in the workers breathing zone ranged from 0.06 to 0.29 ppm (n=6) while formaldehyde levels in area sample s ranged from 0.05 to 0.53 ppm (n=10). These samples were merged from two reports. One report was from 1999 where sampling was done when filling biocide during water injection on an installation and a second report from 2000 includes sampling work at a

bio cide unit at another installation. No other details regarding these repor ts were included in the article and it is not known which formaldehyde containing or releasing biocide was used.

3.3 Diesel Fuel Storage Tank Treatment

Stabicide 71 is proposed f or use as a preservative in diesel fuel contained within storage tanks. The intensity of worker exposure for this use will depend upon the method of addition and the configuration of the tanks. If Stabicide 71 is added by open pouring into the hatch of

a tank that has minimal engineering controls, then formaldehyde exposures could exceed the level of concern of 100 ppb. Conversely, if Stabicide 71 is added using closed system transfer to tanks that have engineering controls to prevent emissions, then it is possible that formaldehyde expo sures would not exceed 100 ppb ; however, a ir monitoring data would be

needed to verify this conclusion.

4.0 Exposure Assessment for Cancer Risks

If workplace conditions are maintained such that peak exposures do not exceed 0.1 ppm,

8 hour daily average exposures will be at least 3 times less than 0.1 ppm because workplace exposures from even the most well controlled processes have a within day variability of at least 3. If it assumed that workers are exposed to aver aged daily concentration of 0.03 ppm for 2 4 0 days per year and 35 years per 70 year lifetime, the cancer risk ranges from

2.2 x 10 - 8 to 5.8 x 10 - 5 depending upon which calculation method is used (IRIS or CIIT)

.

Table 4

– Occupational Cancer Risks for Exposure to Formaldehyde

Average Daily

Concentration (8 hour TWA) Days Exposed

per Year Years

Exposed per

Lifetime Life Time

Average Daily

Concentration A IRIS

Cancer

Risk B CIIT

Cancer

Risk C

0.03 ppm /41 ug/m 3 2 4 0 /365 35 /70 4. 5 ug/m 3 5.8 x 10 - 5 2.2 x 10 - 8

A. LADC = Average Daily Concentration (ug/m 3 ) * (8/24)*(2 4 0/365) *(35/70) B. IRIS Cancer Risk = LADC (ug/m 3 ) * IRIS Unit Risk (1.3 x 10

- 5 per ug/m 3 )

C. CIIT Cancer Risk is taken from Table 8, Part B of Conolly et al.

, 2004 (Light work, Hockey stick C RCP, nonsmoking). It is based on the 8 hour TWA, 5 days per week of exposure and exposures for 40 years of an 80 year lifetime.

5 .0 Human Studies Considerations

All of the exposure studies mentioned in this risk assessment (C ohen, 1994, Linnainma a, 2003

, Steinsvag et al. , 2006 and Steinsvag et al., 2007 ) have been determined by the OPP

ethics reviewers to be observational in nature and did not involve intentional exposure to human subjects.Page 9 of 9

6 .0 References

Cohen, 199 4 . “A Study of Formaldehyd e Exposures from Metalworking Fluid Operations Using Hexahydro

- 1,3,5

- Tris (2

- Hydroxyethyl)

- S

- Triazine, MRID 473354

- 02, H . J. Cohen, University of New Haven, May 3, 199 4

Conolly, R. B., Kimbell, J.S., Janszen, D., Scholsser, P. M., Kalisak, D., Preston, J., and Miller, F.J. 2004. Human Respiratory Tract Cancer Risks of Inhaled Formaldehyde : Dose

Response Predictions Derived From Biologically

- Motivated Computational Modeling of a Combined Rodent and Human Dataset. Toxicological Sciences: 82 (279

- 296).

Linnainmaa, 2003. “Control of Worker’s Exposure to Airborne Endotoxins During Use of Metalworking Fluids”, Markuu Linnainmaa, Hannu Kivirata, Juha Laitinen and Sirpa Laitinen, Kuopio Regional Institute of Occupational Health and National Public Health Institute Department of Environmental Health, Kupio, Finland, AIHA Journal 64:496

- 5000, July/August 2003.

Steinsvag et al., 2006. “Exposure to Oil Mist and Oil Vapour During Offshore Drilling in Norway, 1979

- 2004”, K. Steinsvag, M. Bratveit and B. Moen, University of Bergen, Ann. Occupational Hygiene, Volume 50, Number 2, pp. 109

- 122, 2006.

Steinsvag et al., 2007. “Exposure to Carcinogen s for Defined Job Categories in Norway’s Offshore Petroleum Industry, 1970 to 2005”, K. Steinsvag, M. Bratveit and B. M oen, University of Bergen, Ann. Occupational Environmental Medicine, Volume 64, pp. 250

- 258,

2007.

US EPA, 2009. Toxicology Study Requirements (Scoping) and Toxicology Study Review of N, N’

- methylenebis (5

- methyloxazolidin) . Memorandum from Steve Malish to Marshall Swindell and Demson Fuller, D360405, June 17, 2009

US EPA, 2010. Environmental Fate Assessment of Stabicide 71 and Requests for Metalworking Fluids and Offshore Oilfield Use in Drilling Muds where Release in Water

will Occur. Memorandum fro m James Breithaupt to Dennis Edwards and Marshall Swindell, D360401, May 24, 2010.

Sign

- off Date: 06/28/10

DP Barcode: D360880