i

まえがき
労働安全衛生法第 65 条に規定する作業環境測定は，事業場の労働衛生管理の基本となるもので，その的確な実施のために，厚生労働大臣の定める「作業環境測定基準」に則して「作業環境測定ガイドブック」が当協会から刊行されています。
『作業環境測定ガイドブック』（以下，ガイドブック）は，作業環境測定法
施行規則別表の作業場の種類に従ってガイドブック 1（粉じん・石綿・RCF），
同 2（電離放射線関係），同 3（金属類を除く特定化学物質），同 4（金属類），
同 5（有機溶剤）に分かれているほか，デザイン，サンプリングおよび測定結果の評価方法等を説明したガイドブック 0（総論編）と同 6（温湿度・騒音・酸欠等関係）の全 7 冊から構成されてきました。
このうち，化学物質関係のガイドブック 3，4，5 は 2019（令和元）年に「物質別各論」へと改題して発行されたほか，作業環境測定への個人サンプ
リング法の導入に伴い，ガイドブック 0 が『作業環境測定のためのデザイン・
サンプリングの実務』へと継承され，［A・B 測定編（上）（下）］（2021 年），
［C・D 測定編］（2020 年）に分かれて発行されました。
ガイドブック 1 は，鉱物性粉じん，石綿，リフラクトリーセラミックファイバー（RCF）について，その的確な測定の実施のため，作業環境測定基準に則して刊行されてきましたが，ガイドブック 3，4，5 が「物質別各論」として改題され発行されたことに伴い，このたび，装いを新たに『作業環境測定ガイドブック 1［鉱物性粉じん・石綿・RCF］の測定の実務』として発行するものです。内容としては，2018（平成 30）年に改訂され発行されたガ

ii
イドブック 1（第 6 版）から大きな変更はありませんが，用語用字の修正等を行いました。
本書が，作業環境管理に携わる関係各位に広く活用され，作業環境測定・評価の技術水準および精度等の一層の向上に寄与することを期待いたします。
2021 年 11 月

(公社)日本作業環境測定協会

iii

目

次

Ⅰ 粉じんの基礎
1. 物理量と単位および基本物理定数 ··········································· 2
2. 粉じんとは ············································································ 3
3. 粉じんの濃度 ········································································· 4
4. 粉じんの大きさ······································································ 6
5. 粉じんに関係する物理現象 ····················································· 9
5.1 光散乱現象 ·········································································· 9
5.2 重力，遠心力と粉じん粒子 ··················································· 10
5.3 慣性効果と粉じん粒子 ························································· 12
5.4 拡散効果と粉じん粒子 ························································· 13
5.5 静電気力と粉じん粒子 ························································· 14
5.6 熱泳動力と粉じん粒子 ························································· 15
5.7 空気力学相当径 ·································································· 16

6. フィルターの粉じん捕集原理················································ 17
7. 粉じん粒子の粒度分布の表し方 ············································ 19

Ⅱ 1001 空気中の土石，岩石，鉱物，金属または炭素の粉じんの濃度の測定
1. 分粒装置を用いるろ過捕集方法および重量分析方法 ·············· 24
1.1 測定対象粉じん ·································································· 24
1.2 質量濃度測定方法 ······························································· 25
1.2.1 分粒装置 ····································································· 25⑴ 多段平行板式分粒装置 ···················································· 25⑵ 慣性衝突式分粒装置 ······················································· 27

iv⑶ ハイボリウムエアサンプラーに装着する
慣性衝突式分粒装置 ······················································· 29
1.2.2 ろ過材 ········································································ 30
1.2.3 流量計 ········································································ 31⑴ 流量計の種類 ································································ 31⑵ 流量計の較正方法 ·························································· 33
1.2.4 ろ過捕集方法の流量較正方法 ·········································· 35⑴ 流量較正装置とろ過捕集器具の接続 ·································· 35⑵ 流量の補正（面積式流量計） ··········································· 36
1.2.5 圧力計 ········································································ 37
1.2.6 吸引ポンプ ·································································· 37⑴ ローボリウムエアサンプラー ··········································· 38⑵ ハイボリウムエアサンプラー ··········································· 39
1.2.7 天びん ········································································ 39⑴ 天びんの種類とその原理 ················································· 39⑵ 天びんおよび天びん台の設置環境 ····································· 40⑶ 試料の取り扱い ····························································· 41⑷ 天びんの操作 ································································ 42⑸ 天びんの操作手順 ·························································· 43⑹ フィルターのひょう量方法 ·············································· 44
1.2.8 粉じんのサンプリング方法 ············································· 45⑴ 試料の採取 ··································································· 45⑵ 定 量 ········································································· 45⑶ 試料空気の採取時間 ······················································· 46

2. 相対濃度指示方法による粉じん濃度測定 ······························· 47
2.1 相対濃度 ··········································································· 47
2.2 相対濃度計の特徴 ······························································· 47
2.2.1 光散乱方式 ·································································· 47
2.2.2 圧電天びん方式 ···························································· 48

v
2.2.3 粉じん計の保守管理 ······················································ 48
2.3 質量濃度変換係数の求め方 ··················································· 48⑴ 光散乱方式の粉じん計の場合 ··········································· 48⑵ 圧電天びん方式の粉じん計の場合 ····································· 49
2.3.1 質量濃度変換係数の求め方 ············································· 49⑴ 光散乱方式の粉じん計 ···················································· 49⑵ 圧電天びん方式の粉じん計 ·············································· 50
2.3.2 併行測定の際の留意事項 ················································ 50
2.3.3 併行測定を必要としない場合の算出方法 ··························· 52

Ⅲ 1002 遊離けい酸の分析法
1. 遊離けい酸の定義 ································································ 58
2. 粉じんの管理濃度 ································································ 59
3. 粉じん中の遊離けい酸の測定方法の手順 ······························· 61
3.1 粉じん中の遊離けい酸の定量について ···································· 61
3.2 粉じん中の遊離けい酸の分析手順 ·········································· 61

4. 遊離けい酸分析用粉じん試料の採取方法および粒度調整方法 ······································································· 63
4.1 浮遊粉じん ········································································ 63
4.1.1 浮遊粉じん試料の採取方法 ············································· 63
4.2 堆積粉じん ········································································ 63
4.2.1 堆積粉じんの採取方法 ··················································· 63
4.2.2 分析試料作成方法：再発じん方法 ···································· 64⑴ X 線回折用試料の調製方法 ·············································· 64⑵ 再発じん装置の取り扱い方法 ··········································· 64⑶ 再発じん試料採取の留意事項 ··········································· 66
4.2.3 分析試料作成方法：液相沈降法 ······································· 67⑴ 装置および機器 ····························································· 67⑵ 粒度調整のための操作手順 ·············································· 68

vi⑶ 沈降時間の算出法 ·························································· 71

5. 試料の X 線回折分析方法による定性分析 ······························ 73
5.1 遊離けい酸の定性分析 ························································· 73
5.1.1 遊離けい酸を含む鉱物種と X 線粉末回折図形····················· 73
5.1.2 妨害物質 ····································································· 76
5.2 遊離けい酸の定性分析 ························································· 77
5.2.1 試 料 ········································································ 77
5.2.2 測定条件の選定 ···························································· 77⑴ X 線管球の選定 ····························································· 77⑵ X 線管の印加電圧・電流の選定 ········································ 78⑶ スリット幅の選定 ·························································· 78⑷ ゴニオメータの走査速度 ················································· 79⑸ 時定数の選定 ································································ 79
5.3 定性分析の解析手順 ···························································· 80
5.3.1 測定の手順と解析法 ······················································ 80

6. X 線回折分析方法 ································································ 88
6.1 基底標準吸収補正法 ···························································· 88
6.1.1 X 線回折分析方法による遊離けい酸定量法 ························ 88
6.1.2 基底標準吸収補正法による遊離けい酸（結晶質シリカ）の定量 ········································································ 88⑴ 基底標準吸収補正法の原理 ·············································· 88⑵ 試 薬 ········································································· 90⑶ 装置および器具 ····························································· 90⑷ 検量線の作成 ································································ 91⑸ 遊離けい酸定量方法 ······················································· 94
6.2 定量下限 ··········································································· 99
6.2.1 変動誤差の定義と計算方法 ············································· 99
6.2.2 定量下限の算出 ···························································· 99
6.2.3 測定条件と解析方法 ····················································· 100

vii

7. りん酸法············································································· 103
7.1 りん酸法の原理 ································································· 103
7.2 王水添加りん酸法 ······························································ 103
7.2.1 試 薬 ······································································· 103
7.2.2 装置および器具 ··························································· 104
7.2.3 試料の採取および処理 ·················································· 104
7.2.4 分析操作手順 ······························································ 105⑴ 準 備 ········································································ 105⑵ 分析操作 ····································································· 105
7.2.5 最適加熱条件の設定方法 ··············································· 107⑴ リン酸温度による最適加熱条件の範囲の設定 ····················· 107⑵ 微斜長石による最適加熱条件の設定 ································· 108⑶ 石英による最適加熱条件の設定 ······································· 108⑷ りん酸法の最適加熱条件 ················································ 109⑸ フッ化水素酸残さ率の条件 ············································· 109
7.2.6 試料中の遊離けい酸定量法 ············································ 109⑴ 定量条件の確認 ···························································· 109⑵ 試料中の遊離けい酸含有率 ············································· 109
7.2.7 ゲル状物質の生成 ························································ 110
7.2.8 その他 ······································································· 111
7.3 王水・過塩素酸処理法 ························································ 113
7.4 簡略型王水添加りん酸法 ····················································· 114
7.4.1 目 的 ······································································· 114
7.4.2 試 薬 ······································································· 115
7.4.3 装置および器具 ··························································· 115
7.4.4 試料の採取および処理 ·················································· 116
7.4.5 分析操作手順 ······························································ 116⑴ 準 備 ········································································ 116⑵ 分析操作 ····································································· 116

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7.4.6 最適加熱条件の設定方法 ··············································· 118
7.4.7 試料中の遊離けい酸定量法 ············································ 119
7.5 りん酸法および簡略型りん酸法 ············································ 119
7.5.1 りん酸法 ···································································· 119
7.5.2 簡略型りん酸法 ··························································· 119
7.6 定量下限 ·········································································· 119

8. 測定結果の取り扱い ···························································· 120
8.1 りん酸法の場合 ································································· 120
8.2 X 線回折分析方法の場合 ····················································· 121
8.3 作業環境測定結果報告書（A 様式 5A ページ「10遊離けい酸含有率の測定」）に記入する遊離けい酸含有率と管理濃度の取り扱い ········································································· 121

Ⅳ 1003 石綿濃度の測定
1. 石綿の定義 ········································································· 124
2. 石綿の管理濃度··································································· 126
3. 石綿標準試料 ······································································ 127
4. 計数分析法（メンブランフィルター法） ······························ 129
4.1 原 理 ············································································· 129
4.2 捕集方法 ·········································································· 129
4.3 標本作製の準備 ································································· 132⑴ 標本作製器具 ······························································· 132⑵ 標本作製の準備 ···························································· 133
4.4 標本の作製 ······································································· 133⑴ フィルターの処理 ························································· 133⑵ フィルターの透明化 ······················································ 133
4.5 計数にあたっての準備 ························································ 134
4.5.1 顕微鏡での寸法確認 ····················································· 134
4.5.2 顕微鏡観察者の計数寸法の評価 ······································ 136

ix⑴ テストスライドの概要 ··················································· 136⑵ テストスライドの使用方法 ············································· 137
4.6 計 数 ············································································· 138⑴ 計数対象粒子 ······························································· 138⑵ 計数の手順 ·································································· 138⑶ 繊維数の判断についての約束 ·········································· 139⑷ 計数視野領域境界に交差している石綿繊維の取り扱い ········· 140⑸ ブランク値の求め方 ······················································ 140⑹ 計数に際しての注意 ······················································ 140
4.7 石綿繊維数濃度の計算 ························································ 141
4.8 定量下限 ·········································································· 141

Ⅴ 1004 リフラクトリーセラミックファイバー(RCF）の測定
1. リフラクトリーセラミックファイバーとは··························· 144
2. リフラクトリーセラミックファイバーの管理濃度················· 145
3. 計数分析法（メンブランフィルター法） ······························ 146
3.1 原 理 ············································································· 146
3.2 試 薬 ············································································· 146
3.3 装置および器具 ································································· 146⑴ 捕集用器具 ·································································· 146
3.4 計数装置等 ······································································· 147⑴ 標本作製用 ·································································· 147⑵ 顕微鏡 ········································································ 147
3.5 試料の採取条件 ································································· 148
3.6 標本の作製 ······································································· 148
3.7 計数対象粒子 ···································································· 149⑴ 繊維数の判断についての約束 ·········································· 149⑵ 計数視野領域境界に交差している繊維の取り扱い ··············· 150

x⑶ ブランク値の求め方 ······················································ 150
3.8 リフラクトリーセラミックファイバー繊維数濃度の算出 ··········· 152
3.9 定量下限 ·········································································· 152

Ⅵ 付

録

1. 測定用機器の種類およびその原理 ········································ 154
1.1 X 線回折分析方法 ······························································ 154
1.1.1 X 線の基礎知識 ··························································· 155⑴ 波長エネルギー ···························································· 155⑵ X 線の発生 ·································································· 155⑶ X 線の強度 ·································································· 156⑷ X 線スペクトル ···························································· 156⑸ 特性 X 線（固有 X 線）·················································· 158⑹ X 線の吸収 ·································································· 160⑺ X 線の散乱 ·································································· 161⑻ 結晶による X 線の回折 ·················································· 162⑼ 被ばくの防止 ······························································· 165
1.1.2 X 線回折装置の基礎知識 ··············································· 166⑴ 粉末法（デバイ・シェラー法） ······································· 166⑵ X 線粉末ディフラクトメーター法 ···································· 166⑶ X 線の単色化 ······························································· 167⑷ X 線ディフラクトメーターの概要 ···································· 169
1.1.3 X 線回折分析方法の基礎知識 ········································· 172⑴ 定性分析 ····································································· 172⑵ 定量分析 ····································································· 177⑶ X 線回折分析方法の一般的留意事項 ································· 184
1.2 位相差顕微鏡 ···································································· 187
1.2.1 位相差顕微鏡の原理 ····················································· 187⑴ 吸収物体と位相物体 ······················································ 187

xi⑵ 光の干渉と回折 ···························································· 188⑶ 直接光と回折光 ···························································· 189⑷ 位相差顕微鏡における結像の原理 ···································· 189
1.2.2 位相差顕微鏡の構造 ····················································· 198
1.2.3 位相差顕微鏡の操作 ····················································· 198

2. ACGIH による分粒装置の基準 ············································ 199
さくいん ···················································································· 201

Ⅰ

粉じんの基礎2

Ⅰ 粉じんの基礎

1．物理量と単位および基本物理定数
本書で使用する基本的な物理量の名称・記号および単位記号を表Ⅰ.1 に示す。単位記号は，SI 国際単位を基準としたが，使用が認められている単位記
号および一般によく用いる単位記号を併記した。下記以外の物理量および物
理量の記号は，必要に応じて本文中に示した。なお，物理量の記号は斜体で，単位記号は，接頭語を含めて立体で表すことに決められている。また，接頭語と物理量の記号はスペースを空けないで記述する。単位の掛け算，および数値と単位の間は，半角を空けて表す。
表Ⅰ.1 物理量と単位記号
物理量の名称

物理量の記号

単位記号

質量

m

g，mg，μg

物質量nmol，mmol，μmol

長さlm，cm，mm，μm

時間ts，min，h

電流

I

A

モル質量

M

g mol-1

モル濃度

cmol m-3，mol L-1，mmol L-1，μmol L-1

質量濃度

C

g m-3，mg m-3，g L-1，mg L-1，μg L-1

分率％

百分率，10-2ppm

百万分率，10-6

ppb

十億分率，10-9

体積V

m3，dm3，cm3，mL，μL

面積A

cm2，m2熱力学的温度T

K

セルシウス温度

t

℃

圧力

p

Pa，hPa密度ρg mL-1

波長

λ

μm，nm

拡散係数

D

m2 s-1，cm2 s-1

2．粉じんとは 3

2．粉じんとは
空気中に粒子が分散している状態を総称してエアロゾル（aerosol）と呼んでいるが，その発生源や粒子の性状から粉じん，ヒューム，ミスト，煙，霧など種々の呼び名がある。
粉じんは固体が粉砕，研磨，爆破などにより空気中に分散したもので，形，大きさが不均一であるが，粒子の大きさは他に比べて大きい。
ヒュームは固体が蒸発し，その後凝縮したものであり金属の加熱溶解，溶接，溶断などで生じ，粒子の大きさは粉じんより小さい。
ミストは浮遊している粒子が液状であるものを総称し，液体が蒸発凝縮した場合や噴霧などにより生じる。ミスト粒子は発生条件によって大きさはさ
まざまであるが，表面張力により球形をしている。
煙は主に有機物の燃焼生成物，灰分，水分などを含む粒子で球形に近い粒子が集まって塊となることが多い。
本書で測定対象とする粉じんとは，上の意味での粉じんではなく，作業環
境で存在するすべてのエアロゾルを含んでおり，ヒューム，ミストもこの粉じんに含まれる。

4

Ⅰ 粉じんの基礎

3．粉じんの濃度
粉じんを吸入することによって生じる健康障害には，じん肺症，中毒症，がん，アレルギー症などがある。これらの健康障害を含めた職業性疾患の予防のため，労働衛生管理のアプローチとして「作業環境管理」「作業管理」「健康管理」があり，これらをあわせて「労働衛生三管理」と呼ばれる。
このうち，「作業環境管理」は，作業環境中の有害要因を把握して，それらの要因を取り除き，または有害な程度にならないように管理するもので，労働衛生三管理の中でも最も基本となる対策である。
「作業環境測定」は，作業環境管理の中の重要な手法であって，作業環境
中の化学物質等の気中濃度や外部放射線の線量当量率，騒音，気温，湿度等を科学的・客観的手法で測定し，作業環境をできるかぎり客観的に把握するものである。その結果の評価に基づいて，必要に応じ局所排気装置等の設置や改善，作業方法の改善等の措置が講じられ，良好な作業環境の実現・維持につなげるものである。
粉じんについても，法令で一定の作業場（「特定粉じん発生源」に係るもの）について定期に気中粉じん濃度の測定が事業者に義務付けられている。
図Ⅰ.1 は，人と関わりのある「場所」と「粉じんの濃度」の関係を表した

図Ⅰ.1 環境空気中の粉じんの濃度