thorns

How to Stop Thorn and Blackthorn Injury

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An obvious danger to professional and amateur gardeners and arborealists alike is that posed to the hands by thorn from rose, yucca cactus and most seriously in the UK by blackthorn. If you are working in this field you need to understand the risks and how to stop thorn and blackthorn injury.

Thorn strikes and scratches can and often do become swollen and of course painful very quickly after an injury. If you are unlucky plant thorn arthritis or synovitis can be developed.

Fragments of plant matter left in the skin can can cause swelling in the affected joint with pain, stiffness and associated movement restriction. The onset of such symptoms can be delayed for days or even weeks after the injury, often hindering diagnosis.

In extreme cases scans are used to locate the offending matter and then surgery is carried out to remove the thorn fragment. Usually however a course of anti inflammatory drugs can be prescribed and a full recovery ensues.

HOW TO STOP THORN AND BLACKTHORN INJURY

As ever, prevention is better than cure. Traditionally thick leather gloves have been used by people to protect their hands when gardening. Whilst these are cheap and adequate for gross motor tasks such as clearing hedges they are not dexterous and can cause hand fatigue after prolonged use. Also they do not offer much protection against sharp thorns, particularly the long, thin blackthorn threat.

Professionals are increasingly choosing gloves specifically designed to resist puncture threats posed by needles and fine sharps. The best of these gloves allow enough dexterity to handle tools and perform the fine motor skills required.

TurtleSkin gloves and sleeves made with single layers of ballistic fabrics, can help stop thorn and blackthorn injury whilst allowing enough dexterity to easily handle tools and carry out the finest tasks.

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Short Guide to Glove Puncture Testing

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Introduction:

In Europe and North America there is very close agreement in the in required puncture test requirements. There are some differences but more agreement. The most important factor to take away is that there are at least 3 types of puncture threats that glove specifiers need to consider. Large nail, small nail and hypodermic needle. Sadly good performance for one of these penetrators does not predict performance with the others. Gloves engineered for needle may not have high performance for the large nail and like wise large nail performance does not predict needle results. Users have to select glove and equipment designed for there puncture needs.

ANSI/ISEA Puncture Level for “Large Nail”

The ANSI test is best described as the large nail puncture test. The puncture probe is a 5mm diameter (3/16 Inch) with a dull conical tip.

There are 2 other puncture test that are important

  • NIJ 99-144 “Small Nail” ASTM F 1342 Puncture Resistance Levels

  • ASTM F3 2878-10 Hypodermic Needle Puncture 28 Gauge WMI

Of the 3 important puncture tests the “Large Nail” is the least informative about the material performance against sharp threats. The “small nail” and hypo test offer results relevant to sharp puncture threats

ASTM /ISEA 105 (EN388) Level Puncture (Newtons) Large nail

Level

Newtons

Grams force

lbf

0

< 10

0

1

≥ 10

1020

2.2

2

≥ 20

2039

4.5

3

≥ 60

6118

13.5

4

≥ 100

10197

22.5

5

≥ 150

15296

33.7

EN388 “Large Nail” Puncture Levels

The EN388 test is best described as the large nail puncture test. The puncture probe is a 5mm diameter (3/16 Inch) with a dull conical tip.

There are 2 other puncture test that are important

  • NIJ 99-144 “Small Nail” ASTM F 1342 Puncture Resistance Levels

  • ASTM F3 2878-10 Hypodermic Needle Puncture 28 Gauge WMI

Of the 3 important puncture tests the “Large Nail” is the least informative about the material performance against sharp threats. The “small nail” and hypo test offer results relevant to sharp puncture threats

The EN388 and ANSI 105 are off set by one level. EN388 level 4 is equal to ANSI 105 level 5.   

level

Newtons

grams force

lbf

1

20

2039

4.5

2

60

6118

13.5

3

100

10197

22.5

4

150

15296

33.7

NIJ 99-144 “Small Nail” ASTM F 1342 Puncture Resistance Levels

The NIJ-ASTM puncture test is based on a small 1.5mm diameter sharp penetrator. This is not a hypodermic needle but this test simulates a small sharp nail.

Like all penetration tests the “Small Nail” test uses a compression testing machine and a drum head clamp to hold the sample.

Level

Newtons

Grams force

lbf

Low

>20

2039

4.5

Moderate

>60

6118

13.5

High

>100

10197

22.5

ASTM F3 2878-10 Hypodermic Needle Puncture 28 Gauge WMI

We use the standard test for hypodermic puncture resistance. Base on Warwick’s 20 years of needle protection we have developed a set of levels that define a useful range of needle puncture resistance.

Like all puncture tests the needle puncture test is based on a compression testing machine. The sample is held in a drum head clamp.

 

Level

grams

Newtons

oz force

1 ≥

50

0.5

1.76

2 ≥

100

1.0

3.52

3 ≥

200

2.0

7.05

4 ≥

400

3.9

14.10

5 ≥

600

5.9

21.15

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Short Guide to Glove Cut Testing Methods

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Introduction:

Cut testing has 2 primary modes, knife edge only cutting and knife tip cutting. The standard evaluations for glove and safety gear use the knife edge only. The edge only cut data provides a good baseline for users on cut resistance. There is good agreement between the EN388, ANSI 105 an the NIJ cut criteria.  Users and glove specifiers should take note of the scalpel cut data for a better understanding of the actual resistance of the gloves and equipment in service. Real cut injuries generally include the knife tip.

ANSI/ISEA 105 Cut Level (ASTM F 1790-97 or -05)

The ANSI cut levels are based on the force required to cut through the protective material with a razor knife edge.

In this test the tip of the knife does not contact the material only the blade edge.

The most common cut testing method ASTM 1790-97 is based on a cutting distance for the knife of 25mm (1 inch). The force required to cut through the protective material in 25.4mm of knife travel is the test output.  

The levels are set as follows.

(25 mm of blade travel – ASTM F1790-97)
(20 mm of blade travel – ASTM F1790-05)
Level Grams force newtons lbf
1 ≥ 200 2.0 0.44
2 ≥ 500 4.9 1.10
3 ≥ 1000 9.8 2.20
4 ≥ 1500 14.7 3.30
5 ≥ 3500 34.3 7.71

Modified ASTM F 1342 Scalpel Cut Levels WMI

This Scalpel test is alternate to the straight knife cut tests.  This test measures the force required for the Scalpel blade to puncture and cut through the protective material.

Unlike the ANSI cut test the Scalpel test simulate cut events that involve the tip of sharp tools, sheet metal and glass shards.

The levels have been set to roughly correlate to the ASTM cut method, however because this is knife tip test there are differences in material performance.

The cutting force is measured on a compression testing machine with the sample held in a drum head clamp ring.

Level Grams force Newtons lbf
1 ≥ 75 0.7 0.17
2 ≥ 150 1.5 0.33
3 ≥ 300 2.9 0.66
4 ≥ 600 5.9 1.32
5 ≥ 1200 11.8 2.64

NIJ 99-114 cut rating (ASTM F 1790-97)

The NIJ  cut levels are based on the force required to cut through the protective material with a razor knife edge.

In this test the tip of the knife does not contact the material only the blade edge.

The most common cut testing method ASTM 1790-97 is used by NIJ for this rating. The test is based on a cutting distance for the knife of 25mm (1 inch). The force required to cut through the protective material in 25.4mm of knife travel is the output of this test.  

These levels are roughly the same as ANSI 105 levels 2, 3 and 4

The NIJ levels are set as follows.

Newtons Grams force lbf
Low < 5 509.9 1.12
Moderate ≥ 6 611.8 1.35
High ≥ 16 1631.5 3.59

EN388 Cut resistant levels Rotary Knife or ISO13997 Cut testing

The EN388 cut testing program has 2 tests. A test using a rotary knife machine that measure the rotations to cut through the sample. The calibration process for this machine make it unsuitable for some materials at the higher cut levels so a second test method ISO13997 is used. This is a straight razor knife force test. The ANSI 105 cut levels are similar at level 4 but are quite different for level 5. The ANSI 105 cut level 5 is a higher requirement.

Level Cut Index

(turns of knife)

EN388 rotary

ISO13997 testing

cut force Newtons

ISO13997

cut force grams

ISO13997

cut force lbf

1 >1.2
2 >2.5
3 >5
4 >10 13 1326 2.9
5 >20 22 2243 4.9
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