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ASSIGNED PROTECTION FACTORS AND ISO PROTECTION LEVELS
ASSIGNED PROTECTION FACTORS AND ISO PROTECTION LEVELS
There are known knowns
There are known knowns
THE ISO DTS 16973 CLASSIFICATION REGIMEN
THE ISO DTS 16973 CLASSIFICATION REGIMEN
TABLE 18: Protection level classes
TABLE 18: Protection level classes
OBSERVATION
OBSERVATION
OBSERVATION
OBSERVATION
OBSERVATION
OBSERVATION
OBSERVATION
OBSERVATION
OBSERVATION
OBSERVATION
QUESTION
QUESTION
QUESTION
QUESTION
QUESTION
QUESTION
OBSERVATION
OBSERVATION
OBSERVATION
OBSERVATION
OBSERVATION
OBSERVATION
WPF DATA
WPF DATA
WPF DATA
WPF DATA
WPF DATA
WPF DATA
WPF DATA
WPF DATA
WPF DATA
WPF DATA
POSSIBLE PROBE EFFECTS
POSSIBLE PROBE EFFECTS
WPF DATA
WPF DATA
A KNOWN KNOWN
A KNOWN KNOWN
A KNOWN KNOWN
A KNOWN KNOWN
A KNOWN KNOWN
A KNOWN KNOWN
ASSUMPTION
ASSUMPTION
CALCULATION BASIS
CALCULATION BASIS
AVAILABLE WPF DATA
AVAILABLE WPF DATA
Howie et al (1996)
Howie et al (1996)
AVAILABLE WPF DATA
AVAILABLE WPF DATA
Riala & Riipinen, Colton et al (1990)
Riala & Riipinen, Colton et al (1990)
AVAILABLE WPF DATA
AVAILABLE WPF DATA
Tannahill, Colton et al (1989)
Tannahill, Colton et al (1989)
AVAILABLE WPF DATA
AVAILABLE WPF DATA
Myers et al (1984)
Myers et al (1984)
AVAILABLE WPF DATA
AVAILABLE WPF DATA
Zhuang et al (2003)
Zhuang et al (2003)
AVAILABLE WPF DATA
AVAILABLE WPF DATA
Myers & Zhuang (1998)
Myers & Zhuang (1998)
AVAILABLE WPF DATA
AVAILABLE WPF DATA
Hery et al (1993)
Hery et al (1993)
AVAILABLE WPF DATA
AVAILABLE WPF DATA
Liu et al (2006)
Liu et al (2006)
AVAILABLE WPF DATA
AVAILABLE WPF DATA
Han (2002)
Han (2002)
Summary
Summary
TM3, FF-ve AP
TM3, FF-ve AP
PHR, ?-mask, FFR
PHR, ?-mask, FFR
FFR, ?-mask -ve AP
FFR, ?-mask -ve AP
Known unknowns
Known unknowns
CONCLUSION
CONCLUSION

: ASSIGNED PROTECTION FACTORS AND ISO PROTECTION LEVELS. : Owner. : ASSIGNED PROTECTION FACTORS AND ISO PROTECTION LEVELS.ppt. zip-: 188 .

ASSIGNED PROTECTION FACTORS AND ISO PROTECTION LEVELS

ASSIGNED PROTECTION FACTORS AND ISO PROTECTION LEVELS.ppt
1 ASSIGNED PROTECTION FACTORS AND ISO PROTECTION LEVELS

ASSIGNED PROTECTION FACTORS AND ISO PROTECTION LEVELS

Robin Howie Robin Howie Associates ISRP, York, April 2013

2 There are known knowns

There are known knowns

These are things we know we know. There are known unknowns. That is to say, these are things we know we dont know. But there are also unknown unknowns. These are things we dont know we dont know.

Donald Rumsfeldt

3 THE ISO DTS 16973 CLASSIFICATION REGIMEN

THE ISO DTS 16973 CLASSIFICATION REGIMEN

Determine max Lab TIL; Compare max TIL with Table 2 and assign to relevant TIL Level; Apply the Safety Factor relevant to the TIL Level; Determine the Protection Level (PL) Class.

4 TABLE 18: Protection level classes

TABLE 18: Protection level classes

TIL max (%)

Safety Factor

Protection Level

Class

0.001

10

10,000

PL6

0.01

5

2,000

PL5

0.1

4

250

PL4

1

3.3

30

PL3

5

2

10

PL2

20

1.25

4

PL1

5 OBSERVATION

OBSERVATION

From personal experience most high performance devices give much lower Lab TIL than the maxima specified in the EN. So, Lab PF may be higher than the relevant EN NPF for such devices.

6 OBSERVATION

OBSERVATION

PL5 is effectively equivalent to current TM3 and full-face ve pressure P3. A more stringent assessment of the data would set the APF for these devices at somewhere around 20.

7 OBSERVATION

OBSERVATION

PL5 effectively sets the NPF for these devices at 2000 whereas BS4275 set the APF at 40.

8 OBSERVATION

OBSERVATION

The draft ISO classification takes no account of the nature of the device and therefore fails to address factors that could affect performance in the workplace, e.g. sweating during heavy work and/or in hot conditions is likely to be more deleterious with ?-mask -ve performance than with ff-ve or PAPR.

9 OBSERVATION

OBSERVATION

Consider the case where YOU may be exposed to, say, 50 fibres/ml of amosite, and you are offered 3 devices fitted with P3 filters, all meeting ISO PL5: a ?-mask -ve pressure device; a full-mask -ve pressure device; and, a full-mask TM3.

10 QUESTION

QUESTION

How many would choose the ?-mask -ve pressure device?

11 QUESTION

QUESTION

How many would choose the full-mask -ve pressure device?

12 QUESTION

QUESTION

How many would choose the full-mask TM3?

13 OBSERVATION

OBSERVATION

Consider a full-mask PAPR that gave a max TIL of 0.003%: i.e. a Lab PF of 33,000; The device would be assigned to an ISO TIL class of 0.01%, i.e. a PF of 10,000; The ISO Safety Factor would be 5, so giving an ISO NPF of 2,000.

14 OBSERVATION

OBSERVATION

But a known known is that WPF measured for such devices using suitable in-mask sampling probes give 95%iles in the region of 20-100.

15 OBSERVATION

OBSERVATION

The current ISO draft would therefore take us back 20 years to effectively selecting RPE on the basis of NPF.

16 WPF DATA

WPF DATA

There is a fundamental error in how data are presented for WPF studies that involve continuous in-mask sampling. For the inhale part of the sample duration in-mask contaminant is collected. For the exhale part only the non-body deposited contaminant is collected. If all of the contaminant deposits in the body the true WPF is half of the reported WPF. For continuous flow powered or air-fed devices any exhaled contaminant will be diluted by the incoming air; and the true WPF will be about half of the reported WPF.

17 WPF DATA

WPF DATA

It would be prudent to half all WPF results from studies with continuous in-mask sampling; including the data from Howie et al (1996).

18 WPF DATA

WPF DATA

I proposed such correction when drafting of BS4275 but, as such correction would have rolled down into setting very low APF for FFR and ?-mask devices, the proposal was rejected.

19 WPF DATA

WPF DATA

The then available WPF data were evaluated when setting the APF for BS4275: copies of these data should be available in the BSI archives. If not available from BSI the relevant references were cited in BS4275. Further WPF data are now available.

20 WPF DATA

WPF DATA

A major problem, addressed in BS4275, is that most WPF studies carried out in the USA use/used in-mask probes that are likely to have significantly under-measured in-mask concentrations and therefore caused WPF to be significantly over-estimated.

21 POSSIBLE PROBE EFFECTS

POSSIBLE PROBE EFFECTS

PAPR

FF-veP3

UK

14-130 Howie et al (1996)

16-50 Tannahill (1991)

US

728 Colton et al (1990)

95 Colton et al (1989)

22 WPF DATA

WPF DATA

WPF derived from US studies must therefore be assessed with care.

23 A KNOWN KNOWN

A KNOWN KNOWN

The quantitative fit factors that were obtained did not predict which workers would have the highest or lowest WPF. Although the data were limited, it appears there was no correlation between WPF and quantitative fit factor. Colton et al (1989). 8.8.1 Fitting tests only identify gross misfits and do not guarantee adequacy of fit. BS4275: 1997

24 A KNOWN KNOWN

A KNOWN KNOWN

The Zhuang et al (2003) and Han (2002) studies reported correlation between WPF and QnFF. Zhuang et al studied the correlation over a short period and did not address long-term effects. Hans r^2 values for FF <100, the normal pass criterion for such devices, was 0.31 and for FF >100 was 0.02.

25 A KNOWN KNOWN

A KNOWN KNOWN

The Zhuang et al (2003) and Han (2002) studies reported correlation between WPF and QnFF. Zhuang et als data exhibit declining correlation as FF increases above 100. Hans r^2 values for FF <100, the normal pass criterion for such devices, is 0.31 and for FF >100 is 0.02.

26 ASSUMPTION

ASSUMPTION

Where QnFF are available but Lab PF data are not, it will be assumed that QnFF can used as an indicator of likely Lab PF.

27 CALCULATION BASIS

CALCULATION BASIS

Required Safety Factors below will be based on ISO TIL class/95th%ile WPF

28 AVAILABLE WPF DATA

AVAILABLE WPF DATA

Howie et al (1996) 4 x TM3 devices Large diameter deep probe No Fit Testing for workmen. All investigators achieved QnFF >10,000

29 Howie et al (1996)

Howie et al (1996)

Device

5

5

5

5

5

2000

2000

2000

2000

2000

40

130

14

40

40

250

80

670

250

250

Lab PF

QnFF

ISO PF

ISO SF

ISO PL

95% WPF

Reqd SF

Work

men

Investr

R1 (62)

R2 (65)

R3 (33)

All (177)

All (62)

>10000

>10000

>10000

>10000

>10000

na

na

na

na

>10000

10000

10000

10000

10000

10000

30 AVAILABLE WPF DATA

AVAILABLE WPF DATA

Riala & Riipinen (1998) 6 x PAPR, P3, assumed TM3 Small diameter probe, depth not defined. No Fit testing ----------------------------------------------------- Colton et al (1989), PAPR Liu probe effectively flush with inner surface of inner cup All QnFF >1000

31 Riala & Riipinen, Colton et al (1990)

Riala & Riipinen, Colton et al (1990)

R&R

Colton et al

Device

PAPR (31)

PAPR (20)

>2000

na

na

>1000

1000

1000

4

4

250

250

5

>700

200

-

Lab PF

QnFF

ISO PF

ISO SF

ISO PL

95% WPF

Reqd SF

32 AVAILABLE WPF DATA

AVAILABLE WPF DATA

Tannahill (1990, 1991) 3 x Full-mask ve AP with P3 filters Sampling in visor area No Fit Testing -------------------------------------------- Colton et al (1989) Full-face ve Liu probe effectively flush with inner surface of inner cup All QnFF >500

33 Tannahill, Colton et al (1989)

Tannahill, Colton et al (1989)

Device

A (33)

B (28)

All (67)

_ve

>10000

>10000

>10000

na

na

na

na

>500

10000

10000

1000

100

5

5

5

3.3

2000

2000

2000

30

16

50

20

95

600

200

500

-

Source

Tannahill

Colton

Lab PF

QnFF

ISO PF

ISO SF

ISO PL

95% WPF

Reqd SF

34 AVAILABLE WPF DATA

AVAILABLE WPF DATA

Myers et al (1984) 2 x loose-fitting AP PHR Probe on inside surface of vizor opposite mouth Minimum QnFF >1000

35 Myers et al (1984)

Myers et al (1984)

Device

AH3 (22)

W-344 (23)

Both (45)

na

na

na

>2000

1200

1200

1000

1000

1000

4

4

4

250

250

250

37

20

30

30

50

30

Lab PF

QnFF

ISO PF

ISO SF

ISO PL

95% WPF

Reqd SF

36 AVAILABLE WPF DATA

AVAILABLE WPF DATA

Zhuang et al (2003) 2 x ?masks -ve with P100 filters Probably shallow Liu probe ZZ very kindly supplied raw data Study deliberately included wearers with QnFF <100 Only data for wearers with QnFF >100 analysed herein

37 Zhuang et al (2003)

Zhuang et al (2003)

Device

3M 6000 (23)

MSA Comfo ll (20)

Both (43)

na

na

na

>100

>200

>100

100

100

100

3.3

3.3

3.3

30

30

30

c20

c50

c50

5

2

2

Lab PF

QnFF

ISO PF

ISO SF

ISO PL

95% WPF

Reqd SF

38 AVAILABLE WPF DATA

AVAILABLE WPF DATA

Myers & Zhuang (1998) 3 x ? mask DFM, 2 x FFR DM, 8-11 subjects per mask type Probe probably on inside surface of mask All QnFF >100.

39 Myers & Zhuang (1998)

Myers & Zhuang (1998)

Device

Gerson & MSA (20)

All (54)

na

na

>100

>100

100

100

3.3

3.3

30

30

c20

45

5

2

Lab PF

QnFF

ISO PF

ISO SF

ISO PL

95% WPF

Reqd SF

40 AVAILABLE WPF DATA

AVAILABLE WPF DATA

Hery et al (1993) 2 x FFP2, 3 x ?-mask P2, 1 x ?-mask P3 Flush probe No Fit Testing

41 Hery et al (1993)

Hery et al (1993)

FFP2 (29)

FFP2 (30)

?+P2 (29)

?+P2 (29)

?+P2 (30)

?+P3 (30)

37

20

125

17

13

200

na

na

na

na

na

na

20

20

100

5

5

100

2

2

3.3

1.25

1.25

3.3

10

10

30

4

4

30

2

2

2

2

2

2

10

10

50

2

2

50

Device

Lab PF

QnFF

ISO PF

ISO SF

ISO PL

Reqd SF

95% WPF

42 AVAILABLE WPF DATA

AVAILABLE WPF DATA

Liu et al (2006) 2 x ? mask OV Probe on inner surface of mask QnFF with pass level of 100, FF for 3M device ranged 155-15000 FF for Survivair device ranged 219-76000

43 Liu et al (2006)

Liu et al (2006)

Device

3M

Survivair

na

na

155

212

100

100

3.3

3.3

30

30

47

9

2

10

Lab PF

QnFF

ISO PF

ISO SF

ISO PL

Reqd SF

95% WPF rank

44 AVAILABLE WPF DATA

AVAILABLE WPF DATA

Han (2002) 3 x N95 FFR Probe probably on inner surface of mask QnFF 10-200

45 Han (2002)

Han (2002)

Device

3M 8511

MSA FR200

Wilson 10FL

na

na

na

20

5

10

20

5

5

2

1.25

1.25

10

4

4

6

2

3

3

2

2

Lab PF

QnFF

ISO PF

ISO SF

ISO PL

Reqd SF

95% WPF

46 Summary

Summary

The known knowns.

47 TM3, FF-ve AP

TM3, FF-ve AP

Device

TM3

TM3

FF-ve

LabPF/QnFF

>10000

>2000

>10000

ISO SF

5

4

5

WPF based SF

80-670

200

200-600

Source

Howie ea

Riala & Riipinen

Tannahill

48 PHR, ?-mask, FFR

PHR, ?-mask, FFR

Device

PHR

? P100

?-veP3

?-veP2

FFP2

LabPF/ QnFF

>1200

>100

200

13-125

20-37

ISO SF

4

3.3

3.3

1.25-3.3

2

WPF based SF

30-50

2-5

50

2-50

10

Source

Myers ea

Zhuang ea

Hery

49 FFR, ?-mask -ve AP

FFR, ?-mask -ve AP

Device

LabPF/ QnFF

>100

>100

155

212

>40

ISO SF

3.3

3.3

3.3

3.3

2-3.3

WPF based SF

5

2

2

10

5-10

Source

Han

Gerson & MSA

All

OV

OV

N95

Myers &

Zhuang

Liu

et al

50 Known unknowns

Known unknowns

What are the effects of higher then moderate work rates on TIL? (See TNO data on Gas Masks and consider the sweating of wearers working hard; particularly when wearing impervious clothing.)

51 CONCLUSION

CONCLUSION

The current draft ISO classification regimen fails to address the WPF data base and is therefore highly likely to put RPE wearers at unnecessary, avoidable, and thus negligent, risk: particularly for the nominally high performance AP devices.

ASSIGNED PROTECTION FACTORS AND ISO PROTECTION LEVELS
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