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MEMORANDUM

TO: Tina Ndoh, U.S. EPA/OAQPS/SPPD – Minerals and Manufacturing Group

FROM: Eastern Research Group, Inc.

DATE: June 9, 2014

SUBJECT: Comparison of 40 CFR Part 60, subpart V (Standards of Performance for the 

Phosphate Fertilizer Industry: Diammonium Phosphate Plants) and 40 CFR Part 

63, subpart BB (National Emission Standards for Hazardous Air Pollution from 

Phosphate Fertilizers Production Plants)

This document presents a general comparison between the applicability, definitions, emission 

standards, monitoring and operating requirements, and testing and compliance requirements of 

NSPS 40 CFR Part 60, subpart V, and NESHAP 40 CFR Part 63, subpart BB (hereafter referred 

to as subpart V and subpart BB, respectively). Subpart V was last amended on October 17, 2000 

and subpart AA was last amended on April 20, 2006. This document does not encompass 

recordkeeping or reporting requirements: each subpart references the respective general 

provisions.

1.0 COMPARISON OF NSPS 40 CFR PART 60, SUBPART V TO NESHAP 40 CFR 

PART 63, SUBPART BB

The following sections provide a brief comparison of subpart V to subpart BB standards for 

diammonium phosphate (DAP) plants.

1.1 Applicability

Both subpart V and subpart BB apply to DAP production. However, subpart V does not apply to 

monoammonium phosphate (MAP) production and subpart BB does. Subpart V references 

design capacity, while subpart BB applies to major sources. All emission points specified in 

subpart V are also specified in subpart BB. Refer to Table 1.1 for details.

Table 1.1. Applicability Provisions in 40 CFR Part 60, Subpart V and 40 CFR Part 63, Subpart BB

40 CFR Part 60, Subpart V 40 CFR Part 63, Subpart BB

The affected facility is each granular[a] diammonium 

phosphate plant[b]having a design capacity of more 

than 15 tons of equivalent P2O5 feed per calendar 

day [§60.220(a)]

Each new or existing diammonium and/or 

monoammonium phosphate process line[a],[b]at a 

major source [§63.620(b)(1) and §63.620(c)]

No R&D exemption Includes R&D exemption [§63.620(d)]

No SSM exemption Includes SSM exemption [§63.620(e)]
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[a] Although the term “granular” is explicitly used in the applicability of subpart V; subpart BB does not do this, instead, subpart 

BB uses the term “granular” in the definition of a “diammonium and/or monoammonium phosphate process line” (see Section 

1.2).

[b] For both subpart V and subpart BB, requirements apply to: reactors, granulators, dryers, coolers, screens, and mills.

1.2. Definitions

The definitions are nearly identical for DAP, although subpart BB includes a note that the 

phosphoric acid must be “derived from or manufactured by reacting phosphate rock and acid”. 

Subpart BB does define DAP and MAP together, but this does not cause an issue for the DAP 

definition comparison. Refer to Table 1.2 for details.

Table 1.2. Definitions in 40 CFR Part 60, Subpart V and 40 CFR Part 63, Subpart BB

40 CFR Part 60, Subpart V 40 CFR Part 63, Subpart BB

Granular diammonium phosphate plant: any plant 

manufacturing granular diammonium phosphate by 

reacting phosphoric acid with ammonia.

[§60.221(a)]

Diammonium and/or monoammonium phosphate 

process line: any process line manufacturing 

granular diammonium and/or monoammonium 

phosphate by reacting ammonia with phosphoric 

acid that has been derived from or manufactured by 

reacting phosphate rock and acid. [§63.621]

1.3. Total Fluorides Standards

The total fluorides standards are identical between subpart V and existing sources for subpart 

BB. New sources do have a slightly lower (i.e., more stringent) total fluoride standard for subpart 

BB. Refer to Table 1.3 for details.

Table 1.3. Total Fluorides Standards in 40 CFR Part 60, Subpart V and 40 CFR Part 63, Subpart 

BB

40 CFR Part 60, Subpart V

40 CFR Part 63, Subpart BB

Existing Sources New Sources

Each Granular 

Diammonium Phosphate 

Plant: 

30 g/Mg of equivalent P2O5

feed (0.06 lb/ton) [§63.222(a)]

Each Diammonium and/or 

Monoammonium Phosphate 

Process Line:

30 g/metric ton of equivalent P2O5

feed (0.06 lb/ton) [§63.622(a)]

Each Diammonium and/or 

Monoammonium Phosphate 

Process Line:

29 g/metric ton of equivalent 

P2O5 feed (0.058 lb/ton) 

[§63.623(a)]

1.4. Monitoring and Operating Requirements

The most substantial difference between subpart V and subpart BB in regards to monitoring and 

compliance is related to establishing and adhering to parameter monitoring ranges for wet 

scrubbing systems. Each subpart includes requirements to operate a continuous parameter 

monitoring system to record pressure drop, but only subpart BB includes a requirement to 

monitor and record the flow rate of scrubbing liquid. Subpart BB also includes specific language 
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that facilities must operate within the established parameters, whereas such language is not 

included in subpart V. Refer to Table 1.4 for details.

Table 1.4. Monitoring and Operating Requirements in 

40 CFR Part 60, Subpart V and 40 CFR Part 63, Subpart BB

40 CFR Part 60, Subpart V 40 CFR Part 63, Subpart BB

P2O5 Feed Accounting

 Install, calibrate, maintain, and operate a 

monitoring device which can be used to 

determine the mass flow of phos-bearing 

feed to process within an accuracy of ±5% 

over operating range. [§60.223(a)]

 Maintain a daily record of eq. P2O5 feed 

according to procedures in subpart.

[§60.223(b)]

 Install, calibrate, maintain, and operate a monitoring 

device which can be used to determine and 

permanently record the mass flow of phos-bearing 

feed to process within an accuracy of ±5% over 

operating range. [§63.625(a)]

 Maintain a daily record of eq. P2O5 feed according to 

procedures in subpart. [§63.625(b)]

Scrubbing Systems

Install, calibrate, maintain, and operate a 

monitoring device which continuously 

measures and permanently records the total 

pressure drop across the scrubbing system

(accuracy of ± 5% over operating range).

[§60.223(c)]

Install, calibrate, maintain, and operate a monitoring 

system which continuously measures and permanently 

records:

A) the pressure drop across [§63.625(c)(1)], and 

B) the flow rate of scrubbing liquid to [§63.625(c)(2)],

Each scrubber in the process scrubbing system in 15-

min block averages (accuracy of ± 5% over operating 

range). [§63.625(c)(1) and (c)(2)]

Establish allowable ranges, maintain daily averages 

within the established ranges, for pressure drop and 

flow rate. [§63.624 and §63.625(f)]

1.5. Testing and Compliance

The testing and compliance requirements vary in frequency and method between subpart V and 

subpart BB. Subpart V only requires an initial performance test, whereas subpart BB requires 

initial and annual testing. Subpart BB also allows facilities a broader choice of test methods than 

subpart V in determining P2O5 content of feed. Refer to Table 1.5 for details.

Table 1.5. Testing and Compliance in

40 CFR Part 60, Subpart V, and 40 CFR Part 63, Subpart BB

40 CFR Part 60, Subpart V 40 CFR Part 63, Subpart BB

Frequency of Performance Test

Within 60 days of max production rate, but no 

later than 180 days after initial startup [§60.8]

Existing Sources: On or before applicable compliance 

date and then annually. [§63.626(a)(1)]

New Sources: Within 180 days of compliance date and 
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Table 1.5. Testing and Compliance in

40 CFR Part 60, Subpart V, and 40 CFR Part 63, Subpart BB

40 CFR Part 60, Subpart V 40 CFR Part 63, Subpart BB

then annually. [§63.626(a)(2)]

Sampling and Analysis Methods

Total Fluorides: Method 13A or 13B with 60 

minute sampling time and 0.85 dscm (30 dscf) 

sample volume. [§60.224(b)(2)]

P2O5 Content of Feed: The Association of 

Official Analytical Chemists (AOAC) Method 

9. [§60.224(b)(3)(ii)]

Total Fluorides: Method 13A or 13B with a 1 hour 

sampling time and 0.85 dscm (30 dscf) sample volume.

[§63.626(c)(2)]

P2O5 Content of Feed: Various methods from the 

Association of Florida Phosphate Chemists, Seventh 

Edition 1991 and the Official Methods of Analysis of 

AOAC International, sixteenth Edition, 1995.

[§63.626(c)(3)(ii)]